Master the lost wax casting technique for jewelry making. Our articles cover materials, tools, and procedures as well as product reviews and advice.
14K Pink Casting Grain – made with recycled gold
These slow, quiet days of summer are always a good time to review your shop practices before the busy holiday season kicks into high gear. To help you prepare to successfully cast all of the pieces you hope will be…
In each step of manufacturing jewelry, there are many factors that can adversely affect quality. Because of this, process control is very important. Investing is one of those steps in which process control is vital. Most investment manufacturers help the investor control the process variables by providing a consistent product, user instructions and technical support. However, improper handling of the investment powder often destroys their efforts. Improper storage, poor water quality, wrong mixing ratios, insufficient mixing methods, uncontrolled temperatures and others can each reduce casting quality and thus cause loss of production and money. This paper will present some data that will show what some factors do to the various investment properties.
Casting of silver can be fairly easy and these notes are the results of my experience through trial and error as well as instruction from an experienced jeweler and instructor. Mark Ruby the instructor for the Fort Collins Senior Center was instrumental in helping with these notes and instructions. The person that has helped me test and experiment with the different methods is Mary Jo Ziedler. We have made some mistakes and we have had our successes. Mary Jo and I have only performed investment and casting using centrifugal equipment.
The casting department at Stuller Inc. in Lafayette, Louisiana, has been experimenting with casting photopolymer models, and it has found a way for small shops to eliminate the problem of ash residue defects: Adding vents to the casting tree. Anyone who…
Racine and his son, Ittai, a physicist by profession but a top engineer, passed on purchasing the dated facility and equipment, instead opening a new tech-savvy casting workshop. It was here that they designed the Etype automated wax injection system that earned them a 2011 MJSA Thinking Ahead Award. The system features a motorized conveyor belt that brings barcoded molds to an injection station. There they are read and injected using the corresponding stored parameters, then returned on the conveyor belt to a worker, who removes the wax and starts the process over again. The number of wax injection stations used varies between one and four, depending on the volume needs of the manufacturer.
A good practice for preventing investment blowout is to measure the height of the trees before investing. The maximum tree height should be between 0.5 inch and (for larger trees with more metal) 0.75 inch shorter than the fill level of the flask. It’s also important to leave a 0.125 inch gap between the top of the investment and the top of the flask if you are using benchtop vacuum casting with a solid flask.
Dental probes and knives make good wax tools. Your local dentist or dental hygienist or school for the same can supply you with used tools for free. If they don’t.
You will require a 5 to 6 inch by 3 inch wide brass or copper tube, silver solder a cover on both ends a thicker one or double up for the base to retain the heat. Ideally the tube and top plate should be 1/8th inch thick with the base plate being.
Here’s something to aim for: a well laid-out, orderly workshop, well-lit by multiple non glare light sources, well-maintained equipment, electrically and fire safe, with low dust and few procedures involving solvents, with excellent local ventilation at the appropriate work.
This paper describes a process that eliminated fire scale during a vacuum casting cycle. Castings should not have a fire scale problem if the casting are cooled following this procedure.This casting was cooled using this process. This is what it looks like after quenching and brushing with a brass brush.
Clean, fresh investment, water and investment at room temperature, de-ionized or distilled water or water that has been sitting overnight. Follow the proportions suggested by the investment manufacturer. Usually 40cc of water to 100 grams of investment is good. Use a dust filter mask and gloves. Time yourself. Remember: ‘Well begun is half done’.
The internet has put the world at our fingertips. In minutes or less you can start a video chat with a friend in Hong Kong, download a recipe and ingredient list for Pad Thai to your smartphone, or buy a new HDTV. So why shouldn’t you expect the same immediate gratification when shopping for an engagement ring?.
Invented by Victor Joyner, a Chicagobased manufacturing jeweler, patented High Definition (HD) Patterns are made of a light-curing polymer material that can he injected into a silicone mold with very low pressure at room temperature. After hearing about the exceptional detail achieved by these patterns, and the subsequent clean burnout, I decided to put the material to the test in my shop.
AJM recently asked Linus Drogs of AU Enterprises in Berkley , Michigan , to test the new Ultra-Vest MAXX Investment from Ransom ‘ Randolph in Maumee , Ohio . Designed to reduce the formation of gas porosity when casting white gold alloys, as well as provide smoother surfaces on castings made from resin rapid prototype model materials, Ultra-Vest MAXX is a reformulation of Ultra-Vest, the company’s standard gold and silver casting investment. It promises to offer thermal stability under severe casting conditions. Drogs and his staff at AU Enterprises put the investment to the test in the shop. Their results follow.
A very high percentage of investment casting defects can be directly or indirectly attributed to the design of the sprue system feeding metal to the pattern. Defects such as incomplete pattern filling and shrinkage porosity are easily identified as directly related to poor sprue design. Gas porosity might be caused by a poor burnout but it could also be caused by casting at a higher than necessary temperature. And the elevated temperature could be necessary for complete pattern filling through an inadequate sprue system; this is an example of the sprue system indirectly causing a defective casting.
You can begin carving waxes right out of the box with this starter kit. An instruction book offers expert lessons in creating wax models; an assortment of waxes, tools and templates helps you successfully produce your designs with professional results.
If you are experiencing rough surfaces, discolored metal or no-fills, the problem may be in the burnout. When casting, the burnout cycle is an important step that is often treated with indifference. The burnout is not just a means to…
Recently a customer requested that we make her an unusual mother’s ring. She chose a magnificent 3.56 ct. oval blue sapphire as her center stone and this design was made for her ring. The two bezel set side stones, one…