Jewelry Casting Line Solution

As a precious metal equipment expert, we provide a one-stop service to solve any problems with your jewelry casting line.

How to Cast Jewelry by Vacuum Lost Wax Casting?

jewely casting line

Lost wax casting process is one of the most effective production methods for jewelry casting. Regarded by numerous experts as a highly efficient method, its dominance in the creation of custom jewelry, such as rings, bracelets, and pendants can be seconded to none.

Vacuum pressure casting is among the many lost wax casting methods that have propelled lost wax casting usage in the industry. Hundreds of renowned jewelry manufacturers fancy using a vacuum pressurized lost wax casting machine in casting metals such as pure gold, silver, copper, platinum, etc.

It’s of importance to note that casting jewelry via the traditional jewelry casting methods would easily leave you with finished piece prone to oxidation, bubbles, and cracks— making the post-casting process extremely cumbersome.

The vacuum pressure casting process, on the other hand, operates in a closed environment. This ensures that you do not have to worry about oxidation, densification, shrinkage, or porosity of the final product. Vacuum casting method provides high dimensional accuracy and excellent surface finish. Suitable for casting complex-shaped Jewelry, small holes, and thin-walled Jewelry.

Steps for Casting Jewelry via the Vacuum Pressure Casting

  1. The first step is to prepare the wax molds. It’s advisable you weld the wax molds into a wax mold tree (the wax molds can be copied in batches by a wax injection machine or printed by a 3D printer).
  2. Make a lost wax casting mold with a vacuum powder mixer.
  3. Use a wax burnout furnace in melting the wax out of the mold.
  4. Melt the precious metal and fill the entire gypsum of the vacuum pressure casting equipment.
  5. The rough piece of the Jewelry is formed after the melted wax cools.
  6. Remove the excess plaster with a plaster cleaning machine, and you are good to market your Jewelry.

You can bank with Superbmelt to provide you with a one-stop production line solution. The production package ranges from on-site guidance, equipment, and engineers to help you scale through the process.

Superbmelt is committed to solving your casting problems while proffering step by step guide to precious metals. We have been at the forefront of the Jewelry casting industry for 15+ years. We possess professional and meticulous engineers’, on-site training service, and a casting experience of more than ten years.

Superbmelt has helped build dozens of jewelry casting production lines in places like India, Dubai, Australia, Qatar, etc. Our engineers have rich experience in crafting a complex and unique piece of Jewelry.

I wanna build the jewelry casting line

Jewelry Casting Line Process

1st 3D Printing Machine

Jewelry Casting Line Solution

3d printing machine is used for making wax molds, which can directly print the design drawings.

3rd Wax Burnout Furnace

Jewelry Casting Line Solution

It is used for melting and flowing the wax in the plaster mold and a hollow plaster mold is obtained. [Learn More>>]

5th Plaster Cleaning Machine

Jewelry Casting Line Solution

Plaster cleaning machine is used to clean the finished product and get a clean jewelry blank.

Jewelry Casting Line Solution

Making Wax Mold

Jewelry Casting Line Solution

Making Cast Plaster

Jewelry Casting Line Solution

Burnout Plaster Mold

Jewelry Casting Line Solution

Melting and Casting

Jewelry Casting Line Solution

Cleaning Finished Part

2nd Vacuum Investment Powder Mixer

Jewelry Casting Line Solution

Vacuum gypsum powder mixer is used for making plaster moulds for jewelry casting. [Learn More>>]

4th Vacuum Pressurized Casting Machine

Jewelry Casting Line Solution

The vacuum pressurized casting machine is customized to melt and cast gold, silver and other precious metal. [Learn More>>]

Build Jewelry Line Now
1st 3D Printing Machine
3d printing machine is used for making wax molds, which can directly print the design drawings.
2ndVacuum Investment Powder Mixer
Vacuum gypsum powder mixer is used for making plaster moulds for jewelry casting.[Learn More>>]
3rdWax Burnout Furnace
It is used for melting and flowing the wax in the plaster mold and a hollow plaster mold is obtained. [Learn More>>]
4thVacuum Pressurized Casting Machine
The vacuum pressurized casting machine is customized to melt and cast gold, silver and other precious metal. [Learn More>>]
5th Plaster Cleaning Machine
Plaster cleaning machine is used to clean the finished product and get a clean jewelry blank.
Build Jewelry Line Now

How to cast jewelry: Jewelry casting process and casting line configuration solution

 

Chapter 1:

History of Precious Metals

It’s no news that at the fair mention of the word ‘Precious metals’ the first thing that comes to mind are naturally occurring metallic chemical element of high economic value. Precious metals are among the oldest elements on the earth’s crust.

Notable for the high investment and industrial value they possess, we would like to have a little peek at the history behind the three major precious metals used in jewelry casting. The precious metals on our list include gold, silver, sterling silver, and platinum.

Possessing incomparable market value within numerous industries, Gold, silver, and platinum are regarded as the most sought out precious metals of all time.

Gold

This malleable ductile metal is ranked 79 in the atomic table. Naturally known for its yellowish bright colour, gold is the least naturally occurring element amongst all the precious metals available on our list but unlike any other precious metal, its market value is always on the rise.

Gold is mainly used in crafting jewellery, coinage and arts. 50% of the gold used globally were mined from Witwatersrand, South Africa.

Frequently noted by numerous ancient Greek texts and literature for its eloquence in medical, financial and the technological industry, its usage dates as far back as 40,000 BC.

Traced back to a Spanish cave during the late Paleolithic period, Gold gained widespread usage during Egypt’s Pre-dynasty period.

Ranging from medals to trophies, idolatry artefacts to holy wares its usage has paved path for a notable cultural and spiritual uprising and growth.

Relevant Facts About Gold

  • Golds purity is determined by its carat weight
  • The ocean contains over 20 million tons of gold.
  • Traces of gold are contained in our blood
  • Gold is widely regarded as a component of the sun.

Sliver

A lustrous metal capable of conducting heat and electricity. Silver is ranked 47 in the atomic table. Popularly known for its shiny nature, silver is one of the most treasured precious metal used in making jewelry.

Sharing the same solubility as gold, most of the silver utensils and pieces of jewelry being made are a combination of copper and silver. Silvers usage dates as far back as 3000 BC during Egypt’s Pre-dynasty period.

Apart from its renowned influence in the production of Jewellery’s and electronics, antimicrobial properties capable of preventing bacteria build-up in cloths are contained in the element. 85% of the silver used by numerous industries worldwide are mined from Peru and Mexico.

Before the inception of paper currency, silver was widely regarded as a viable means for monetary trade.

Relevant Facts about Silver

  • Consumption of silver can cause blue pale skin.
  • Separation of gold from silver can be done through heating with salt.
  • Silver’s abundance on the earth crust is estimated to be about 0.08 parts per million.
  • Compared to most other heavy metals, silver possesses low toxicity.
  • Silver plays an influential role in tons of notable medical applications

Platinum

Are you tired of having to craft your jewelry out of a particular metal? Platinum is a family of them all {platinum, iridium, palladium, ruthenium, rhodium, and osmium}. Recently imbibed into the jewelry casting process, Platinum is listed amongst the least reactive metals.

Platinum was first used in ancient Egypt in creating artefacts. Platinum gained widespread usage in Spain after it acquired the tag ‘little silver’. Platinum’s rare refining process made it impossible for it to acquire notable usage in the Jewellery making industry until the 1900s after the invention of the oxyhydrogen torch.

The noble metal has been acknowledged by numerous experts as a component of catalytic converters used in automobiles. South Africa is home to some of the biggest platinum mining industries. Over 80% of the platinum used annually are mined within the region.

Platinum plays a major role in the creation of anti-cancer drugs due to its low reactivity levels.

Relevant Facts about Platinum

  • Platinum’s weight does not oxidize
  • Only a few hundred tonnes of platinum is produced annually
  • Platinum possesses six naturally occurring isotopes.
  • Platinum is commercially obtained as by-products from nickel and copper mining
  • Platinum has an extraordinarily high resistance to tarnishing and corrosion.

1.1, When does the mining and use of precious metals begin?

From the previous chapter, you might have noticed that one of the key characteristics behind every precious metal is its rarity on the earth’s crust. Precious metals have been able to retain an influential stance past time and space due to its unmatched ability to create an impeccable portfolio suitable for any investment policy with a profitable hedge against inflation.

The mining of precious metals began in ancient Egypt in 3600 BC. While no particular reference was made by any history book regarding the first precious metal to be mined from the surface of the earth, most history books place Gold as the bone of contention while referring to its usage globally.

The first precious metal minted coin was created in 564 BC by King Croesus of Lydia. Gold mining gained widespread usage in Rome after it was inculcated into their monetary system in 58 BC. In 1717 AD Great Britain adopted the pure gold standard; few years after a huge number of silver mining locations were discovered in Mexico, Bolivia and Peru.

By 1751 AD platinum was globally recognised as an element. Its took it a few hundred years to gain a reputable spot as a precious metal. Gold operated as a protective tool against radiation in the first manned spaceflight in 1961 AD. In 1967 AD, South African mint created the first gold bullion coin for carrying out transactions. South Africa is currently regarded as home to notable gold and platinum mining industries.

Since the dawn of the 21st century, precious metals have grown to become the most sought out means for creating ornaments and Pieces of jewelry.

While its influence in commerce is still as productive as ever, its solubility and rarity have enabled it to excel in numerous other industries worldwide. Ranging from automotive, electronics and jewelry creation to investments, chemical and the medical industries, precious metals have gained a dominative spot.

Circulating currencies: precious metals long history in commerce haven’t depreciated in any way. Modern storage facilities still utilise gold bars and silver ornaments in carrying out monetary transactions. It’s of importance to note that amongst the long list of precious metals available, only silver and gold are still in circulation as currencies.

Electricity and Electronics: a lot of electronic devices and appliances found in our homes contains gold and sterling silver bars. Globally known for their ability to conduct heat and electricity, the shiny precious metals have become a must-use element in most electronic companies.

Investment: what better way is there to ensure that you get a substantial return for your funds than investing in metals that cannot be replicated by men. While paper money investment is still as viable as ever, the depreciable nature they possess has made its investment returns incomparable to that of gold bars.

Pieces of jewelry and Ornaments: dating as far back as 40,000 BC, precious metals were used in creating Egyptian artefacts and burial rite tools. Finding any 21st-century jewelry company that does not utilise any or all of the above listed precious metal is impossible.

1.2, When do precious jewelry appear

Our previous chapter explained the mining process and notable uses of precious metals in the 21st century. Since we are now familiar with the facts and figures, let’s dive into its usage in the Jewelry industry.

At the fair mention of the word Jewelry, the first thing that comes to mind are rings, necklaces, earrings, pendants, bracelets, cufflinks and the likes. Since the dawn of time, numerous cultures and traditions have enjoyed the reputable adornments that putting on a priced piece of ornament comes with. Ranging from cowries to beads and now metals and gemstones, jewelry has undergone its fair share of growth and decline since time inception.

Few years after the widespread use of precious pieces of jewelry in Egypt, hundreds of significant crafts in Mesopotamia were redesigned with precious metals. Most of the precious jewelry created in Mesopotamia was a combination of precious metals and gemstones. By 1600 BC, casting, twisting bars, and making wire had become a popular technique for precious jewelry creation in Greece. Usage of precious rings in Greece skyrocketed after the Persian war. While the Persians didn’t fancy flaunting precious jewelry, it was widely used as gifts and worn by wealthy women.

After the Romans conquest, heavy weighted gold leaf and silver was used in creating religious and pollical ornaments. Light-weighted gold leaf was adopted in the creation of precious jewelry during the middle age by the Byzantium empire. At the dawn of the 17th century when commerce had gained widespread acceptance within the whole of Europe, there was an increased dominance in the usage of precious metals and gemstones in creating jewelry.

The birth of modern archaeology in the 18th century brought about an industrial revolution that provided access for middle-class individuals to partake in the exciting thrill attached to putting on precious jewelry. Art Nouveau came to fusion in the late 1890s. Art Nouveau explores the usage of precious ornaments in decorating houses and pathways. The English name for Art Nouveau is Modern style.

Pacific North and south America and Indian have also had a long history with jewelry. Precious pieces of jewelry gained widespread usage within the above-listed regions about 2000 years ago.

1.3, Precious Jewelry in Modem Day

Science and technology have undoubtedly taken the world by surprise. Its dominance in almost every industry has made thousands of renowned ring casting methods and styles possible. With 3D printing ad modelling software available, crafting numerous jewelry styles and designs out of precious metals have become possible.

The long list of designers, fashions and trends have paved the way for the creation of impeccable precious jewelry designs. The United States is ranked as the largest jewelry market with over 30% shares while China and Europe are regarded as influential contributors to the global market.

Chapter 2:

How to Choose the Best jewelry Casting Method

When it comes to jewelry casting, the type of method you chose to use is of utmost importance. Unlike most other notable casting processes, Jewelry casting requires strict adherence and care. Mistakes or negligence during casting can cost you a fortune. While our FAQ section is designed to help you scale through each time you come across a blockade while casting, taking out time to ensure that you are on track during the process would save you a lot of hassle and stress.

Here are a Few Things to Consider before Choosing a Jewelry Casting Method

Suitable Casting Material: no individual would fancy going through the hectic process of casting to end up with a piece of jewelry with little to no strength or resistance to corrosion. Selecting the right alloy would require checking out the shape, size, texture and weight.

Specific Product Requirements: before diving in jewelry casting, you would have to make up your mind as to what you would like the end product to look like. Whether you are trying to cast a piece of jewelry for yourself or you have a huge customer base at your wake, operating without accessing the product requirement and specifications can lead to miscalculations in the metal casting process.

Project/Tool Cost: the type of jewelry casting machine required is dependent on the casting method. Jewelry casting is an expensive venture, to ensure that you don’t end up at the losing end, it’s essential an estimate on the project cost is carried out before the casting process begins.

Wax Casting: Amongst all the notable casting techniques that renowned jewelry casting experts have used in creating jewelrys since time inception, Wax casting technique is among the few that have been able to withstand the test of time.

Wax casting ring technique utilises a wax model of a specific object in creating the mold. After the creation of the mold, molten metal is poured into the created mold to produce a sculpture. Wax casting influential position in creating small jewelry settings of any shape and size have made it one of the most sought out casting technique of all time.

While there are tons of notable wax casting methods available, we would focus on the two jewelry wax casting methods operating with the lost wax casting jewelry {investment casting} technique ‘Vacuum casting method and Centrifugal casting method’.

Designed to enable users enjoy a stress-free process and well-polished jewelry designs, hundreds of notable jewelry casting companies utilise the productive influence that the above-listed jewelry casting methods provides.

Since we are familiar with all the facts attached to wax casting, lets jump into the casting methods and processes involved.

2.1, Vacuum casting method

Vacuum casting method involves the usage of vacuum casting machines to suck the molten metal into the mold. Functioning with almost the same tool and procedures as centrifugal, the vacuum lost wax casting method is notable for its requirement for the flask to be loaded in a sleeve within a chamber to enable the forced vacuum to inhale molten metal into the investment.

Tools required for Vacuum Casting

  • Pattern Wax: pattern wax are completely combustible materials that can be filled with soluble wax for hollow forms. Operating with a material void of this form would leave room for residue which is quite detrimental to the casting process.
  • Sprue wax:this is a wax used in attaching sprue to the main sprue tree.
  • Investment: adequate investment supply suitable for one to six-month casting project. Endeavour to apply hand lotion before using bare hands to mix investment.
  • Scale: a laboratory scale that can be used in weighing the size of metal, wax and investment needed for the job.
  • A Mixer: substantial mixing equipment for mixing the investment. A bowl and scoop would also suffice.
  • De-bubblizer:a vibrating platform capable of eliminating bubbles within the model and investment.
  • Burn out oven:a furnace system for heating the wax and investment.
  • Torch: Oxygen/Acetylene torch capable of melting metals.
  • Eye protection: a dark eye ware capable of keeping your eyes at a safe distance away from the lightning-caused by the torch.
  • Heat resistant gloves and tongs: you don’t want to use your hands in removing heated up flask. Heat resistant gloves and tongs provide speed and increase efficiency.
  • Crucible:a cubicle big enough to hold as much molten metal as desired for the casting process.
  • Stirring rod: suitable object such as carbon rod for stirring melted metal and for removing impurities.
  • Flux:Borax powder or any suitable flux for cleaning the flask after burn out.
  • Gallons of Water:used in cooling off the flask after finalising the casting process.
  • Fire extinguisher:in case of any unnecessary burn out that may occur.
  • Vacuum casting machine

Known for its ability to produce big series of functional materials, the first step in vacuum casting is placing a two-piece mold in a vacuum chamber. After the vacuum chamber absolves the mold, the end product is solidified in an oven.

Utilizing this prototyping method would ensure that you get to enjoy a small number of polyurethane prototype parts with highly accurate results.

Unlike most other jewelry casting methods, vacuum casting possesses a shorter production time. vacuum casting machines are a bit expensive but purchasing any would ensure that you don’t have to go through the rigorous balancing procedure that the other lost wax casting rings method requires.

2.2, Centrifugal casting method

Centrifugal casting method has been at the forefront of the casting industry for hundreds of years. The first centrifugal casting machines dates back to 1807. Generally known for casting hollow pipes and tubes, the smooth and efficient casting style involved has been inculcated into wax jewelry casting.

Centrifugal jewelry casting process involves the use of the centrifuge force to create inertia capable of distributing metal into the hollow cavity. Designed with a flask placed in a cradle on a swing arm in direct alignment with a crucible, the melted burn out produced from the hollow cavity is dependent on the heat frequency, induction and the torch used in melting the metal. After a maximum melting point has been attained, the inertia reduces and the burnout is poured into the flask.

Tools Required for Centrifugal Casting

  • Pattern Wax: pattern wax are completely combustible materials that can be filled with soluble wax for hollow forms. Operating with a material void of this form would leave room for residue which is quite detrimental to the casting process.
  • Sprue wax: this is a wax used in attaching sprue to the main sprue tree.
  • Sprue bases and flask: a flask big enough to carry the mold when placed in the furnace system.
  • Investment: adequate investment supply suitable for one to six-month casting project. Endeavour to apply hand lotion before using bare hands to mix investment.
  • Scale: a laboratory scale that can be used in weighing the size of metal, wax and investment needed for the job.
  • A Hand Mixer: substantial mixing equipment for mixing the investment. A bowl and scoop would also suffice.
  • De-bubblizer: a vibrating platform capable of eliminating bubbles within the model and investment.
  • Burn out oven: a furnace system for heating the wax and investment.
  • Torch: Oxygen/Acetylene torch capable of melting metals.
  • Eye protection: a dark eye ware capable of keeping your eyes at a safe distance away from the lightning-caused by the torch.
  • Heat resistant gloves and tongs: you don’t want to use your hands in removing heated up flask. Heat resistant gloves and tongs provide speed and increase efficiency.
  • Crucible: a cubicle big enough to hold as much molten metal as desired for the casting process.
  • Stirring rod: suitable object such as carbon rod for stirring melted metal and for removing impurities.
  • Flux: Borax powder or any suitable flux for cleaning the flask after burn out.
  • Gallons of Water: used in cooling off the flask after finalizing the casting process.
  • Fire extinguisher: in case of any unnecessary burn out that may occur.
  • Centrifugal casting machine

The casting process attached to using the centrifugal lost wax casting rings is dependent on the surface tension of the molten metal. Casting delicate metals would require more force to enable the machine to create durable molds.

When making use of centrifugal casting method, keeping a tab on the force been exacted by the centrifuge when creating a mold is of utmost importance. Excessive force can cause damage to the hollow cavity while too little wouldn’t be able to fill up tiny areas of the mold.

Centrifugal machines require the usage of a protective fence to ensure that molten metal doesn’t escape in situations where blow out occurs. While learning how to cast jewelry using the centrifugal method, adhering to the instructions listed below would enable you to avoid casting with flasks that are off-balance.

  1. Insert the investment into the centrifugal machine {not burnout}
  2. Slide the cubicle to the mold and insert the required amount of metal for the flask into it.
  3. Endeavour to keep the centre nut loosened to avoid screeching.
  4. Make a preferred adjustment to the counter-balance weights
  5. Ensure that the weight nut is well tightened.

2.3, Other traditional casting methods

Lost wax casting might have been able to garner a reputable number of individuals and companies to its casting methods but it isn’t all there is. The other notable casting processes available are plaster mold casting and sand casting.

Sand Casting

You wouldn’t find a better casting method for casting small molds at a profitable cost. Sand casting has been in use since the dawn of ancient Egypt. Its reliance on silica-based materials enables users to gain access to a casting process void of tearing and cracking. With the inclusion of clay to the sand casting process, a durable amount of flexibility during the cooling phase is obtainable.

Sand casting does not provide much room for the creation of ornaments and jewelrys like investment casting. Its credibility is widely acknowledged in the automotive and housing industry. Amongst all the traditional casting methods available, sand casting is the most cost-effective and suitable casting method for casting ferrous and non-ferrous materials.

Sand casting, on the other hand, is a bit unreliable in terms of accuracy. Gaining accurate measurements while casting components with specified size and weights can keep you at its wheels all day. Sand casting process bounds objects together using clays, chemical binders, or polymerized oils. Sand casting does not require as much maintenance as other casting methods.

Plaster Mold Casting

Sand casting and plaster mold casting shares a similar process. The major difference between the two-casting process is the mold material being used. Plaster mold casting utilises gypsum, strengthening compound, and water.

This casting process also requires the use of anti-adhesive compounds. These compounds are coated around the pattern to avoid stockage with the mold and to fill up cracks that might occur during casting.

While the plaster mold casting method does not provide wax molds for casting jewelry, the method is a bit cost-efficient for casting large molds. Plaster mold casting provides users with a smoother and more accurate surface than sand casting.

The casting technique can only be used with low melting point non-ferrous materials. Plaster mold method is termed expensive by most casting companies due to the high cost of maintenance it possesses.

2.4, Comparison of multiple casting methods

Casting methodAdvantagesDisadvantagesUsesBurn out cycle
Vacuum casting methodShort production time.

Notable degree of accuracy.

Smooth surface finish.

A bit expensive.jewelrys, pipes, flywheels, cylinder liners.1600° F for 12 to 16 hours
Centrifugal casting methodA high degree of accuracy.

Capable of creating tiny wall parts with accurate geometrics.

Extremely smooth surface finish.

Quite expensive.jewelry, pipes, flywheels, cylinder liners.1600° F for 12 to 16 hours
Sand casting methodLittle requirement for maintenance. Can be easily recycled.

Suitable for casting ferrous and non-ferrous materials.

Low accuracy level.

Creates products with a rough surface finish.

Automotive and housing equipment.Less than a week
Plaster mold casting methodSmooth surface finish.

Can cast surface shape with thin walls.

Better dimensional accuracy than sand casting

Quite expensive

High requirement for maintenance

Casting equipment of complex geometryLess than a week

 

Chapter 3:

What to do before casting precious metals

Casting precious metals can get a bit rusty if you are not familiar with the processes involved. Even with the huge number of tools and machines currently available, individuals who embark on the casting process are still at high risk of getting injured without the right equipment.

Whether you are looking to learn how to make a mold for silver casting or a vacuum jewelry casting equipment is already handy and you are looking to dive straight into precious metal casting, there are a few things that must be put into consideration before kick-starting this venture.

Consider the Casting Concept

Like every other project, the first thing to consider when casting precious metals is the concept. Creating a workable concept would enable you to navigate your path while designing patterns.

Casting precious metals requires detailed planning and design. As soon as you finalise a workable concept, then you can use CAD software such as RhinoGold, JewelCAD, or 3Design to create 3D printed patterns that correlate with the initial concept.

Creating a wax Patten via a CAD software would enable you to get an insight on the end product. To get jewelry wax pattern suitable for the job, it’s important you make use of Resin 3D printers while creating the desired patterns.

Ensuring that the casting process is error-free is the key reason a lot of renowned casting companies fancy creating a digital model after designing the patterns via CAD software. Digital models can be created using fabrications from 3D printers.

Picking a Suitable Castable Resin

Most jewellers are diehard observers of traditions due to the incomprehensible market value most ancient jewelry designs have over recent once. While tons of new jewelry designs are created on a daily, it’s essential you settle for castable resins with the ability to work on the traditional process. The two major types of 3D castable resin printer available are laser SLA and UV LCD.

Factors to Keep in Mind

  • The casting material in use.
  • Small sprues which are a bit labour free compared to larger feed sprues can be used in filling the runner.
  • It’s of importance to ensure that the filigree part designed is as self-supporting as possible.
  • To minimize the expansion force on the investment, creating thin-walled shell designs would go a long way.

3.1, Obtaining Pure Precious Metals

3.1.1 How to get pure gold

Gold amongst all the other precious metal is the most valuable. It has built a notable reputation across numerous industries. The precious metal is mined in the form of ore. While pure gold can only be obtained from the surface of the earth, it’s of importance to note that the mining process would only provide you would gold nuggets, to obtain ‘pure gold’ you would have to follow few sets of instructions.

Gold nuggets also known as ore are a combination of numerous minerals such as silver copper, platinum etc. Pure gold is the end product of smelting and aqua regia refinement.

Being mined in the form of ores, the gold nugget undergoes smelting {heating the gold nugget to melting point}. After the heating process, the aqua regia refinement process is applied to remove all sort of impurities from the smelted gold.

Procedures involved in Obtaining Pure Gold

  1. For every ounce of gold, pour 30 millilitres of nitric acid and 120 millilitres of hydrochloric acid into a container.
  2. Leave for 6 to 8 hours.
  3. Use filter paper in removing any particle that the mixture might have created.
  4. Mix one pound of urea in a quart of boiling water and mix with the acid.
  5. Endeavour to carry out this mixture slowly so as not to create a mess from the bubbling reaction.
  6. Mix another quart of boiling water with storm precipitant. Ensure that for every ounce of gold an equal ounce of the precipitant is added.
  7. Stir till a muddy brown colour mixture possessing a strong odour is gotten.
  8. After 35 to 40 minutes, you can check for dissolved gold by using a gold detection liquid, stirring rod and a paper towel.
  9. Insert the stirring rod into the mixture, then place the edge of the rod on a paper towel. Apply gold detection liquid on the wet spot, if a dark brown colour is derived, then there is still gold to be extracted.
  10. Wait for the mixture to form separated layers then pour out the top surface. Beneath the layers lies the gold.
  11. Rinse with water, aqua ammonia then water again. At the time a texture is regained, you would have obtained 99.9% pure gold.

3.1.2 How to Obtain Sterling Silver

Before we go into details regarding the processes involved in obtaining sterling silver, we would like to straighten a particular fact. Sterling silver is not pure silver. Sterling silver contains a purity of 92.5% while pure or fine silver contains a purity of 99.9%. Casting silver rings at home with sterling silver would provide you with a piece of jewelry containing copper, nickel and zinc.

Possessing the same malleable nature as gold, sterling silver is a mixture of copper and silver. With copper occupying less than 8% of the precious metal, a lot of enterprise and jewelry casting companies across numerous part of the globe have acknowledged its marketing value. While sterling silver is notable for its durability, its life span cannot in any way be compared with that of pure silver.

Most sterling silver casted jewelrys are plated with fine silver to provide it with a glittering nature. To ensure that users can easily differentiate between sterling silver and fine silver, most of the silver bars sold are marked with initials such as 999 and 925 depending on the region the product is being sold from. The silver bars marked 999 represent fine silvers while does of a lesser number contains a silver purity of the specified number.

Procedures involved in obtaining sterling silver from traditionally worn-out equipment.

  • Put on your safety gears and pour your silver objects into a cubicle.
  • Put cubicle on a furnace.
  • Heat till melting point {1763 degrees Fahrenheit}
  • After removing from fire, use a graphite stir rod to remove the slag attached to the top of the molten silver.
  • Pour into a mold of choice, after it cools down, stir in water.

3.1.3 How to Obtain Pure Platinum

While platinum might not be able to boast of the same market value like gold or silver, its rarity on the earth crust and extraction process is similar to no other. Generally extracted from ores, pure platinum is a combination of minerals such as sperrylite and platinum arsenide. Obtaining an ounce of pure platinum would require 12 tonnes of ore and a minimum of six months. Unlike most other precious metals, platinum creates room for users to enjoy a dense metallic element with high resistance to corrosion.

Dating as far back as 700 BC, its appliance encompasses the jewelry casting industry, medicine, electronics and housing.

Pure Platinum’s Extraction Process

The platinum extraction process is quite labour intensive, before jumping into it, its essential you take out time to estimate the cost.

  • The major platinum-containing ores are sperrylite and cooperite. After extracting a platinum ore of choice, the next process is crushing.
  • Crushing the mined ore would enable you to acquire a smooth surface area containing all the precious materials contained in the ore.
  • Individual compounds can then be separated from the dissolved mixture in the form of slurry via immersion in water.
  • Platinum is quite dense so its certain that the raw product would settle at the bottom of the water. After it settles, pour out the individual compounds and leave to dry.
  • At this stage, the concentrated platinum is 99% pure. To remove the 1% impurity left, heat the concentration with an electric furnace to 2732F° (1500C°).
  • The above-stated procedure would enable you to remove impurities such as iron and sulphur, to extract nickel and copper impurities, you can employ electrolytic and chemical techniques.
  • To dissolve platinum metal from the mineral concentrate, pour the extracted platinum in a concoction of nitric acid and hydrochloric acid. This forms a concentration of chloroplatinic acid
  • Ammonium chloride can be used to convert the chloroplatinic acid into ammonium hexachloroplatinate. Burning out the ammonium hexachloroplatinate would form pure platinum metal.

3.2, Designing Jewelry

Since we are familiar with all the facts and figures attached to the materials used in casting rings, let’s get down to the designing business.

Like most other ventures, designing a reputable piece of jewelry would require ample time and funds. Undergoing a jewelry casting training before diving into the venture would enable you to obtain a notable stance in the competitive industry within a limited time.

As you might have already known, idea rules the world. With the huge number of jeweller available, proffering creative ideas is of the essence when starting. To come across suitable designing ideas, you can explore the internet, stores or even personal jewelry. One of the most notable methods most renowned jeweller use in acquiring an influential position ahead of the competition is checking out vintage jewelry products.

Jewelry can be designed via beads or precious metals. Bead jewelry designs are mostly homemade and do not require strenuous processes. The supplies used in making bead jewelry are a precious gem, string, wires, beads, pliers and scissors.

Precious metals, on the other hand, requires a molding and casting process. We would talk about all the steps and procedures involved in casting jewelry in the coming chapter, for now, we would like to talk about suitable devices for casting jewelry.

3.3, Select device

With tools like silver casting machines and gold ring casting kit providing companies and jewelry casting expert with a time saving and cost-effective casting process, you wouldn’t have a hard time trying to learn how to make a mold for silver casting.

Regardless of whether you prefer the traditional casting tools and equipment over the use of machines or you prefer the Vacuum jewelry casting machine over the centrifugal jewelry casting machine, our list comprises of must-have tools and devices. You can select a preferred design from a manufacturer of choice.

  • 3D Printing – CAD machine:3D printing machines are required for printing patterns and castable designs. With numerous variants of 3D machines available for 3D printing, you wouldn’t have a hard time navigating a CAD machine of choice.
  • Burnout Ovens:it’s impossible to carry out a successful casting process without utilizing burnout ovens. Tons of electric burnout oven with programmable controllers are available at our store.
  • Casting kits:kits of numerous sizes to help you kickstart the casting process.
  • Alloys and Grain:pick a preferred casting alloy and grain. Could be gold. Silver, platinum or any metal of choice.
  • Investing supplies: this comprises of supplies such as mixers, tables, scoops, timers, rubber bowls and the likes.
  • Metal melting device:casting torches have become a necessary tool for jewelry casting due to the solid nature most metals possess.
  • Mold supplies:this includes knives, mold clamps, frames, mold release spray etc.
  • Sprue cutters:protruding parts from plastic moldings, trees and metals can be a pain in the ass if necessary measures are not taken. Sprue cutters can be used in eliminating such issues.
  • Vulcanizers:vulcanizers is quite essential to the molding process, available in numerous size and price, you would find a lot of suitable vulcanizing machines at our store.
  • Wax injector:to avoid numerous common defect mechanism, it’s advisable you utilise the productive influence of a wax injector during molding.
  • Wax carving tools:tons of wax carving tools of different shape and size capable of retaining hot or cold texture are required during jewelry casting.
  • Sprue wax:for attaching sprue to the main sprue tree during tree building.
  • Porosity removers:this jewelry casting tools are used in burnishing metal. Capable of filling porosity issues that might arise during casting.
  • Mold rubber:mold rubber or silicone used in creating mold.
  • Investment:adequate investment supply for creating mixture used in casting is required.
  • Flask and basin:flask and basins for inserting mold and alloy into the furnace for casting.
  • Vacuum pressurized jewelry casting equipmente: suitable for casting jewelry via the vacuum pressurised casting style.
Chapter 4:

How to Make Jewelry by Vacuum Casting

A lot of jeweller have settled for lost wax casting jewelry service due to the remarkable portfolio it built over the years. Popularly acknowledged for the vacuum casting method it offers, its usage requires strict adherence to numerous steps and procedures. Ranging from the wax mold making process to the steps involved in polishing and cleaning the desired product, this chapter covers it all.

Step 1, Making Wax Mold

To create a wax mold traditionally, you would need a wax sculpture with sprues, plaster of paris, water and containers. If all the materials listed above are handy, let’s dive into the creation process.

  1. Make a Plaster Mixture:one notable instruction that most plaster packages come with is that users should add water to plaster, while this isn’t far from the truth, it’s advisable you carry out the instructions the other way around. Pouring water into plaster would create bubbles which can be detrimental to the desired result. To avoid such scenario, endeavour to slowly pour plaster mixture into the water.
  2. Time to stir:You can stir the mixture with hands to ensure that probable lumps are well dissolved. Plasters are quite light and would dissolve easily in water. To create a wax mold, a thick mixture is needed. Purchasing a big bag of plaster before embarking on the job would go a long way.
  3. Insert your Wax Sculpture:after a thick solution is acquired, insert your jewelry wax sculpture {Sculpture down, sprues up} into the mixture. While inserting, try to ensure that the wax doesn’t touch the bottom or side of the container. Hold at the middle with the sprues out till you feel the mixture grabbing a hold of it.
  4. Leave the plaster to set {might require 6 to 12 hours}
  5. Remove mold from the container.
  6. Melt the wax out with a conventional oven.
  7. To easily separate the desired wax mold from the mixture, you can make use of vulcanizers. Set the vulcanizer to 315 deg.F, and leave the mold to heat up. Ensure to crank down the handle of the vulcanizer during this process. Allow each layer of mold to heat for approximately 5 minutes then allow cooling. You can pull out the wax mold by pulling on the protruding sprue.

If you are in search of a casting pattern that is cost-saving, time-saving, able to complete a complex task and provide smooth surfaces, the traditional wax mold making style wouldn’t suffice.

Use 3D Printers

With hundreds of 3D printers offering jewellers numerous designs and style for casting patterns, you wouldn’t have a hard time designing a prototype via a castable resin. The 3D printing material allows jewellers to turn digital designs to 3D prints suitable for casting.

3D Castable Resin and 3D Not Resin Castable Resin

3D Castable resins mold are made out of an inflammable organic substance that is insoluble in water and is obtained from trees and other plants. 3D castable resins provide a flexible burn out schedule but require strict adherence to the manufacturer’s instructions when purchasing materials needed for investment.

3D not Castable Resin are made out of an artificial material derived from various organic polymers like nylon, PVC, polyethylene, etc. It is mostly referred to as a legacy product that requires more specific and gentle burnout schedule.

 

Insertion of Wax into Mold

After creating a pattern of choice via a suitable 3D castable resin, you can easily insert wax into mold by using a wax injector. Utilizing a wax injecting machine enables you to insert wax into the mold without distorting its shape. This procedure is suitable for creating duplicate wax molds.

Step 2, Making Wax Mold Tree

Creating a wax mold tree is the next phase. If the above-listed procedures are followed to the letter, you would have succeeded in creating wax molds suitable for building a wax mold tree. To traditionally create a wax mod tree, you would have to attach the post-processed prints to a main wax sprue with sticky sprue wax.

During this process, you might run into complications while trying to join numerous prints to a wax sprue. You can make use of a super glue or fast setting epoxy to rectify such issues.

After creating a wax mold tree possessing a similar nature to your original design, it’s essential you stick the mold tree into a debubblizer solution and wait till it regains a dry texture before proceeding

Step 3, Making Plaster Mold

Plaster molds are notable for their rare ability to duplicate structurally complicated objects. If your jewelry design is a bit old fashioned or a bit out of the ordinary, then making a plaster mold would enable you to figure out a suitable casting process in good time.

Since you are already familiar with the fact that plaster in its liquid form is extremely malleable and can withstand a high temperature of heat, let’s dive into the mold making process. To make a plaster mold the traditional way, you would require an object to duplicate, glue, modelling clay or similar material, mold spray, paintbrush, a plastic box with four corners, paper plate, Play Doh, wax and boiling water.

Steps Involved in Making Plaster Mold the Traditional Way

  • First thing first, look for a container big enough to fit the amount of plaster needed for the object you would like to duplicate. Trim the perimeter to size and stick to your overspill guard using a glue. Ensure that the height of the container you are making use of is taller than the object you are about to duplicate.
  • Insert your play doh into the created perimeter than place the object you would like to duplicate on it. it’s of importance to ensure that the play doh doesn’t cover more than half of the object. Also, ensure that the object does not contain any sort of opening. It might cause complications during extraction.
  • Create an artificial tube around the perimeter of the object so as to create room for molten materials to be poured when the plaster solidifies. To enjoy easy alignment between the two plaster parts after creation, you can use the end of a pencil-like object to create indentations around the play doh.
  • Apply mold spray around the object, play doh and containers’ perimeter to enable easy removal after making a plaster mold.
  • Mix your plaster mold with water and stir continuously to avoid lumps. You can use a powder mixer in hastening the process. When a texture of taste is acquired, pour gently into your container. Endeavour to pour the mixture from a specific corner and allow to flow around the container naturally to avoid bubbles.
  • After filling, detach the perimeter form the overspill guard, flip the plaster to the other part and re-glue. Remove the play doh and object from the plaster mold and follow the same procedure in creating a second part.
  • Remove the object and play doh from the second part after it solidifies. Join the plaster wax mold together by tying with rope. Melt wax {or any material of choice} in an oven and pour into the plaster mold. Try to be as careful as possible to avoid spillage on your finger.
  • Wait till the wax or material in use solidifies. You can pour boiling water on the surface of the plaster to remove spillage. Carefully open the plaster mold.

Using Powder Mixer

The traditional method of mixing plaster with bowl and water might seem interesting but its usage can leave bubbles capable of causing a flux during jewelry creation. To avoid the hassle of bubbles and water drops, exploring the opportunities a Vacuum powder mixer machine offers would go a long way. Most powder mixers can hold a maximum of 5 Pcs of 12.7* 25.4cm and one pc of 45*35cm.

Burn Out

After acquiring a desired solution via the vacuum powder mixer, pour the mold into a casting flask. Operating with a recommended burnout schedule, all that is needed is the insertion of the casting flask into the heating oven. This usually takes hours. it’s advisable you use a well-ventilated furnace to guarantee adequate airflow within the chamber.

Step 4, Melting and Casting Process

The melting and casting process sums up the whole job. With our main focus being on vacuum pressurized jewellery casting machine, just follow these steps and you are good to go.

  • Remove the wax mold from the heating oven after burnout.
  • Place the wax mold into the vacuum pressurized jewellery machine casting chamber.
  • Start metal melting and casting under the vacuum and pressurised circumstance.
  • The inert gases condition on which the machine operates on would enable you to avoid oxidation during casting.
  • When the metal melts, take out the flask and place it on the casting pad.
  • Set the flask aside to cool.

Step 5, Washing and Polishing

You ae done with the casting process and your jewelry is ready but is not looking as beautiful as you would like. To get the authentic nature of fine jewelry, you would have to wash and polish the

recently casted piece. Here is a list of tools needed for washing and polishing your jewelry.

  • Jewelry saw
  • Carborundum paper
  • Super pickle & pickle pot
  • Abrasives
  • Polishing compounds

Steps Involved in Cleaning

  1. Use a jewelry saw to cut off sprue
  2. Grind the remaining sprue left on the jewelry with Carborundum paper and bits.
  3. Put the piece of jewelry in a concentrated pickle solution to remove investment.
  4. Use steel, brass or wire brush to clean off the remaining investment depending on how rough it is.
  5. Clean with a medium abrasive such as sandpaper.
  6. Use a burnisher to burnish the piece.
  7. At this stage, you would have acquired a nice piece. You can use cratex wheels to checkmate any imperfections that might be left.

Using Cleaning Machine

If the above process is seeming a bit hectic or time-wasting, you can lessen the hassle by utilizing a cleaning machine. Different types of cleaning machines capable of providing your jewelry with the sparkling nature you desire are available in our lobby.

After cleaning, it’s time to polish the acquired piece. To polish, you can use abrasive polishing paste such as bobbing, Tripoli and red rouge. To provide the piece with a glittering nature, endeavour to polish the piece with the above-listed abrasives based on the order it’s written.

Step 6, Precision machining

With hundreds of jewelry casting machine manufacturers available, you would certainly come across thousands of notable jewellery casting machines. To enjoy a stress-free casting process, you must be willing to patronise machines from the best suppliers within your region.

Superbmelt provides a technical manufacturing service that is essential in creating and designing machines, parts, tools, and other hardware that are essential in modern manufacturing to maintain process controls and tolerances that function under extremely tight specifications.

Focused mainly on jewelry casting machines, you can expect to find a wide range of jewellery wax machine, ring casting machine, jewelry cleaning machine, wax injection machine etc in our Jewelry casting kit.

Chapter 5:

How does Superbmelt’s vacuum casting process solve the problems caused by the casting process

Superbmelt is designed to provide a one-stop casting service for your precious metal casting line. Known for our reputability with numerous famous brands, our machines are pack filled with features capable of providing an exceptional casting experience to individuals and companies.

With loads of jewelry casting machine for sale, a 24 hours support service and a professional R&D team to enable us to keep up with the ever-changing pace of the digital world, you can expect reliability at its peak from the services we provide.

5.1, Air Entrainment in wax

Air entrainment in wax is amongst the most popular defects that can occur during jewelry casting. This defect can occur in situations were jewellers operates with an insufficient mold venting system.

Its corny ability to leave you unaware of its presence during casting have dented the casting process of hundreds of fine jewelry. This jewelry casting defect can occur in two ways;

During wax injection into mold

Air entering the mold via external sources.

Air entrainment is generally caused by air incapable of finding an escape route during casting. Air that gets entrained during wax injection or from external sources creates lumps and air spaces in the solidified wax.

Issue of air entrainment can also arise in scenarios were the furnace system used in casting isn’t functioning at its optimal level.

How to Identify Air Entrainment in Wax

While the eyes remain our most trusted asset when trying to identify visual problems, you might have a hard time navigating air entrainment defects within wax banking on its navigational abilities alone.

Its advisable jewellers looking to identify air entrainment issues make use of a microscope but in situations where a microscope isn’t handy, you check for obvious symptoms like a protruding recessed cavity along the jewelry’s surface.

Note that the size of the cavity on the wax is dependent on how deep the air entrainment in wax is.

Effects of Air Entrainment in Wax

Can lead to the formation of bubbles within the jewelry’s structure

Issues of breaks within the structure would easily arise

Weakens the texture of the structure

Manufactured jewelry would easily break under stress

Probable Solutions

Avoiding air entrainment issues can be a bit tricky but it’s very much possible. One of the easiest ways to avoid issue of air entrainment is by checking the durability of the mold venting system before casting.

Regular cleaning of the gaskets and other parts of the furnace system would also go a long way in ensuring that issues of air entrainment don’t arise. Cavities caused by the air bubbles can be rectified by filling up the bubbles with an extremely hot pointed object.

5.2, Wrinkled Surface

wrinkled surface is the most common jewelry casting defect. Notably known as a ‘burn out process’ defect, jewellers who are in a rush to finish up the investment casting procedure are at high risk of coming across this defect.

It’s no news that the furnace walls are the hottest part of the interior. Placing a flask close to the walls would create room for wrinkled surface issues. Wrinkled surface generally occurs in surfaces made to endure a hotter heating process than other parts of the flask.

Inserting your flask into the furnace without proper observation of its positioning would leave you prone to wrinkled surface issues.

How to Identify Wrinkled Surface

We don’t think you would need the dictionary definition of wrinkle to get a palatable insight on what a wrinkled surface defect looks like. Notably caused on surfaces exposed to a hotter temperature during burnout, wrinkled surface defects are in most cases confined to a particular part of the item.

Effects of Wrinkled Surfaces in Wax

While there is no proven track record that wrinkled surface defect would have a negative influence on the mechanical strength or the microstructure of the item, its tolerance would undoubtedly leave you with an end product possessing a rough and detestable look.

Probable Solutions

To avoid issues of wrinkled surface, before heating up the furnace system, ensure that the flask is positioned at its centre. Proper exposure of every part of the flask to heat reduces the possibility of wrinkled surface defect by a huge margin.

To provide a smooth nature to a priced piece losing its value due to the wrinkled surface defect, thorough grinding and polishing of the surface would come in handy.

5.3, Tree Building Defects

The tree building process is among the few that you can’t afford making a mistake on.

Amongst the long list of defects mechanisms jewellers are prone to encounter during casting, tree building mistakes are widely regarded as a common source.

A tree building mistake would undoubtedly affect the end product of your piece. It’s quite essential you take out as much time as possible to ensure that your wax tree is built in an appropriate manner.

Identifying Tree Building Defects

The same way tree building effect can occur in numerous ways, so too can jewellers easily identify a piece void of this defect mechanism in different ways.

A well-crafted jewelry item void of tree building defects are known to possess smooth and seamless tree and wax joining points capable of providing a piece free of wrinkled surfaces.

Items with this defect are known to possess unwarranted spacing within the wax and protruding parts likely to break off when in contact with intensified heat.

You can visually analyse your jewelry casting item to ensure that the joining points of the tree are efficiently glued leaving no room for protruding parts capable of creating cavities at break-off to form.

Effects of Tree Building Defects

Affects the mechanical strength of the end product.

Leaves room for easy breakage of jewelry when exposed to stress.

Probable Solutions

Nobody fancies the thought of crafting a unique piece of jewelry easily prone to breakage or mechanical failure.

Unlike during most other jewelry making process, jewelers are advised to take extreme care when building a wax tree. We know that the modelling and coupling stage can be a pain in the ass — we are certain you wouldn’t have a hard time navigating your way around it if an exceptional piece is what you desire.

In scenarios were the tree building defect easily meets the eyes, you would have to melt and re-insert the wax into the tree to obtain a fine piece of jewelry.

5.4, Dewax Defects

Yeah, we know you want to feel the excitement attached to holding up your first piece of jewelry

Time and money can also be saved by jewelry casting companies operating with a hastened investment process.

But from experience, we advise –don’t hasten the investment process.

Dewax defects can arise as a result of hastened investment process. Popularly known for the liquid traces it leaves on the surface of the casted item, dewax defect affects the mechanical texture of the end product.

Identifying Dewax Defects

Jewellers can visually identify jewelry dewax defect by checking the surface of the jewelry item after casting for watermarks.

Poor investment usually causes a flow of liquid around the surface. This flowing rivulet of liquids is capable of leaving watermarks after solidification.

Effects of Dewax Defects

Numerous studies on dewax defects state that jewelers do not have a lot to worry about since it doesn’t go beyond the surface of the casted item.

This can be termed probable on occasions were the dewax defect affects a minimal part of the casted item –but in scenarios where the defect is exceedingly glaring, it’s important to note that you can easily end up with a finished product possessing little to no mechanical texture.

Probable Solutions

As we had already stated, jewelers or jewelry companies operating on minimal time or funds during the investment casting process are prone to this defect.

To avoid the antagonizing nature of this defect mechanism, it’s essential you invest as much funds and time as required into the investment casting process. Cautionary precautions and conscious effort to increase the investment processing time can also hinder any possibility of a Dewax defect occurring.

5.5, Cold Shuts

Just as the name implies, Cold shut defects are capable of leaving you with cold feet after spending hours or even days casting a fine piece of jewelry if adequate precautions are not taken.

Cold shuts defect can be caused by low casting temperature on alloys or metals used in casting. Unlike wrinkled surface defects caused by uneven heating –cold shuts are triggered on areas of the flask with little to no exposure to heat.

A lot of casting companies refer to cold shuts as gaps that arise in places where the molten metal are unable to mix. These gaps arise as a result of the turbulence that occurs before solidification, areas with little to no settlement of the molten metal flow are prone to cold shut defects.

Identifying Cold Shut Defects

You wouldn’t need a microscope to detect the flawed nature of cold shuts. A glance at a casted item suffering from cold shut defect would send your mind in the right direction.

Characterized by discontinuities, a lot of jewelers mistake cold shut defects for crack. To differentiate between the two, it’s advisable you look at the edges of the casted item, cold shut defects might consume a tangible portion of the object’s surface, but the edges are always unaffected.

Cold shut groves can also be identified by a visible pattern. Caused by molten metals unable to mix during turbulence, a closer look to its pattern would provide you with a visible sight of two molten metals flowing towards each other but stops halfway due to inadequate turbulence flow.

Effect of Cold Shut Defects

Cold shuts usually create room for space to within the material unavoidably leaving it mechanically weakened.

Materials with cold shut defects would easily widen or degenerate under stress.

Due to the discontinuities, the crafted piece would possess a rough surface finish. While polishing and grinding might provide it with an approachable look, its surface quality remains below peer.

Probable Solutions

To avoid the wrinkled surface that can arise from cold shut defect, placing the flask in the middle of the furnace is quite essential.

Cold shut is a defect caused by low temperature in the furnace, increasing the intensification of the furnace would go a long way to resolving the issue.

Take precaution not to increase the heat above the desired degree or you might end up with numerous other common defects after casting.

5.6, Crack

Excessive application of stress on the surface of the material is one of the major causes of cracks. Notably known for its tricky nature of devouring the casted material from inside, this defect mechanism is associated with the bad surface on tubes manufactured from continuous ingot casting.

Slowly tearing the material from inside, cracks are hardly noticed during casting. You can enjoy a smooth and efficient casting experience with little to no knowledge that the smooth surface that meets the sight is an illusion.

Cracks usually become visible when adequate stress is applied to the material when finalizing the casting process.

Identifying Cracks

Cracks in most cases are represented by long continuous stretch breaking and extending into smaller once. There are sceneries were jewelers can come across small cracks scattered all over the material. Cracks are undoubtedly among the few defect mechanisms that can make you start all over. Its ability to tear deep into the jewelry lowers the productive value and influence its geared to have in the market.

Effects of Cracks on Materials

Due to probable segregations that can arise as a result of cracks, the microstructure and grain structure level of the casted material would at most times remain questioned. This defect mechanism targets the mechanical strength of the material. The gaps and loosed ends it creates does not leave much room for jewelers to obtain an end product that can be termed ‘worth the hassle’

Probable Solution

While you can easily come across scenarios where you wouldn’t notice any sign of crack till you start polishing or cleaning your piece, paying as much attention as possible to detail during the casting process can enable you to enjoy an efficient casting process void of this defect.

One of the major causes of cracks is the appliance of excessive stress on the material. During casting, only apply as much force as required. Try to avoid applying unwarranted force/stress on the material.

5.7, Pores and Inclusions

If you are planning to land an exceptional piece after casting for hours, then you might want to put this at the back of your mind.

‘You can’t go about the casting business in a hastened or nagging manner’

Adequate time and preparation are required. Pores and inclusion defect can result in scenarios where jewelers dwell on the end product more than the procedures involved.

Pores and inclusion defects are capable of arising during the pouring of liquid into the mold, during the investment mixture, or while building the wax tree. This defect leaves room for high heat to break off brittle metal parts.

Identifying Pores and Inclusion Defects

Inclusion usually takes up surface space while pores are regarded as the empty spaces removed inclusion leaves behind. This defect is notable for its ability to exist only when the inclusion on the surface has been removed.

To identify this defect, look for visible pores taking the shape of an inclusion removed from the surface. Impurities can also in most cases be referred to as inclusion, so you can also identify this defect by keeping an eye out for surfaces were impurities were recently removed from.

Effect of Pores and Inclusion on Material

Since a smooth surface remains the desired goal of most jewelers, it’s impossible to neglect the effect pores and inclusion defect can cause. This defect mechanism can create room for individuals to come across a disfigured surface after casting. Fixing this defect would undeniably cost you more funds.

Probable Solutions

With pores and inclusion defect leaving a visible sight, the first thing that comes to the mind of a lot of jewelers is to try out polishing —unfortunately, this only worsens the case. The best alternative to pores and inclusion defect is to melt the material and start all over again.

5.8, Fins

The investment casting procedure is widely known as the easiest and most cost-effective but due to its uncanny ability to leave your end product at ruin if precautionary measures are not taken, a lot of common defects mechanism have been attributed to its process.

Casting with increased pressure on the investment can arise fin defects. High carats alloys are known for the higher densities they possess. Operating at a higher density above most other alloys, the investment is subjected to increased pressure.

This increased pressure paves the path for fins to arise on the material’s surface. Usage of low-quality investment materials can also trigger fin defects.

Identifying Fin Defects

Fins usually appear at the edges of the casted material. They are represented by slender shoots of metal materials. This defect mechanism can only be visually identified after the investment and wax tree have been made two separate entities.

Fins are irregular shaped and can be formed at the bottom of the flask were the pressure is highest. While fins usually show up in isolation, there are scenarios where you can pinpoint its presence in a material by examining the surface. Most materials possessing this defect mechanism tend to have a rough surface.

Effects of Fins on Materials

You would hardly find a jeweler who would fancy an end product that doesn’t possess the eye-catchy nature that the global market desires. Fin defect might not be able to cause mechanical or structural setbacks, but its ability to leave jewelers with a rough surface has earned it a ‘cost-effective and time taking venture’ tag.

Probable Solutions

Paying adequate attention and taking out time to create a durable and accurate investment mixture would go a long way in ensuring that the issue of the fin defect mechanism doesn’t arise. Issues of fins can be eliminated by polishing and cleaning the finished piece.

5.9, Shrinkage Porosity

Shrinkage porosity is among the few defect mechanisms that can arise as a result of poorly designed models. Operating with a model that does not possess an efficient gated design would eliminate the capability of molten metals to fill up empty spaces before solidification occurs.

For solidification to occur, it’s evident that the liquified metals would have to shrink. In scenarios where the molten metal placed in a poorly designed model with no credible allowance for the flow of molten is exposed to quick cooling, a solidification process which can lead to Shrinkage porosity occurs.

Identifying Shrinkage Porosity

Unlike most other common defects that occur during casting, shrinkage porosity is a bit more complex and can cause reputable damages to the end product if reliable solutions are not proffered.

Notably known to occur after the metal solidifies, you cannot easily access the pores formed with your naked eye. Although, there are a few cases where the defects are made visible to the naked eye in the form of black patches.

To check for shrinkage porosity issues, you can make use of a microscope or a device of similar nature to check for pores connected in a dendritic shape.

Effects of Shrinkage Porosity on Materials

Shrinkage porosity defects leave room for gap within the material. Its presence in a material creates spacings within the microstructure levels providing it with an increased tendency to experience breakage. This can also give rise to mechanical failures in situations where stress or force is applied to the material.

Probable Solutions

Due to the fact that this defect becomes visible only after solidification has occurred, you wouldn’t find a lot of probable solutions except starting all over again. To avoid repetition of this defect, endeavour to design your model in a way that the gates and channels are optimised for free and easy flow of molten metal around the material.

 

Chapter 6:

Conclusion

Jewelry casting dates as far back as 700 BC. Since its inception, hundreds of notable jewelry rings casting process has been created. Metals such as gold, silver and platinum are widely regarded as the best material for casting a fine piece of jewelry due to their malleability and rarity on the earth crust.

Whether you fancy the traditional jewelry casting process contained in this piece or the renowned vacuum pressurized jewellery casting machine and lost wax casting equipment we proffer is seeming like the perfect option, there are two must-haves ‘Time and Money’. Jewelry casting is a strenuous job, without adequate preparation and investment, exploring the profitability the craft offers would be impossible.

Chapter 7:

FAQs

What are the probable causes of small bubbles on casting?

When the investment is too vicious; 2. When the working time allocated to the investment to degas flask is too short; 3. When bubbles are trapped against the pattern.

Is there a dedicated time attached to mixing the investment and preparing the mold?

No specific time is dedicated to mixing the investment, although, if you would like to enjoy a smooth and clean casting process, it’s essential you utilise a powder mixer while mixing the investment.

How do I remove the porous surface on casting?

To remove the porous surface on casting, add reservoirs to the sprue tree.

Why am I having a pitted surface after casting?

Pitted surface is caused by the ash residue that results from incomplete burnout.

Apart from a wax heat pen, what other viable alternatives are available in joining a print to a wax tree?

In scenarios where the pattern is too fragile for a wax heat pen, you can use a fast setting epoxy or super glue in sticking print to the wax tree.

What are the effects of metal flashing in a mold?

Metal flashing can cause the investment to become weak thereby becoming cracked or damaged during burnout.

How can I remove Jagged blobs on casting?

There are a few things you can try out when jagged blobs are formed on casting. Some of the notable solutions are decreasing the amount of water during investment, increased the required bench set time after investment, create larger spacings between resin patterns.

Are they homemade methods for polishing a piece of fine jewellery?

There are a few homemade methods available for polishing fine jewelry. To get detailed instructions on all the processes required, you can check out this piece.

What is lost wax jewelry casting?

Lost wax jewelry casting is the process of creating a duplicate metal sculpture from the original. It's notable for the precision it provides.

What is casting wax used for?

Casting wax is required when designing a fine piece of jewelry. After wax casting occurs, the liquified material is poured into a mold which is then left to form a solidified material.

What type of wax is used for investment casting?

Different types of wax can be used for investment casting. The preferred choice is dependent on the part of the wax pattern on which you are working on. The available wax are Filled Pattern waxes Un-filled or Non-filled Pattern waxes, Runner waxes, Water-soluble waxes, Repair Waxes and Sticky waxes

What materials can be used for casting?

The material that can be used for metal casting includes Titanium alloy, Gray iron, Aluminum alloy, Steel, Copper and Zinc.

Is investment casting expensive?

Compared to most other forms of casting, investment casting is a bit expensive. Note that most other forms of casting cannot provide you with the smooth surface finish and mechanical properties that investment casting provides.

Why is it called the lost wax method?

Investment casting is also known as lost wax casting, because in the beginning wax model is created as per your desired casting pattern, then the liquid metal is inserted into the mold and the wax model is melted and wipe-out. The metal gets harden and get the desired shape similar to casting pattern.

What are the advantages of investment casting?

The major advantage of investment casting is that unlike in traditional casting procedures were the molten metal depends on gravity to flow into the cavities of the mold, investment casting ensures that the molten metal is forced into the cavities of the mold with either centrifugal force or the vacuum casting method.

What is vacuum casting process?

Vacuum casting process is a technique whereby vacuum is used to draw the liquid material into the mold. This process is used when air entrapment is a problem, there are intricate details or undercuts, or if the material is fibre or wire reinforced.

What is shrinkage allowance in casting?

Shrinkage allowance in casting is known as a time during casting whereby the material in use shrinks {reduces in dimension and volume}. Shrinkage allowance taking place during the first two stages of casting is called liquid shrinkage while shrinkage during the third stage is known as solid shrinkage.

What is the difference between mold and cast?

A mold is an impression of an object or organism while a cast can be seen as the final step that follows after the mold. Notable known as two distinct processes in jewelry making, for only after the creation of a mold do you get to cast.

What materials can be used as molds for pewter casting?

The materials required for making a mold during pewter casting include Object to cast, Small box, Sulfur free clay, RTV rubber, Mold release spray, Liquid pewter and Baby powder.

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