Refractory Material and Mold Mixes

The below powder materials are used for Casting Glass, Bronze, metals and other materials, for making furnaces for glass blowing and other applications.

To learn how to use these materials we recommend buying a book. There are two excellent books on glass casting, "Glass Casting and Moldmaking" and "Pate de Verre and Kiln Casting of Glass". Click here for the books.

Mold Mix

A Castable Refractory mix developed specifically for glass slumping and casting.

Brand	10 Pound Bag	50 Pound Bag
SunTech Mold Mix	$18 #15410	$65 #15450
Master Mold Mix	$24 #15403	$90 #15404

Two Brands:

• Master Mold Mix - the origional
• SunTech - Our mix - we feel is as good or better than the origional Master Mold Mix - at half the price

The following are some characteristics that make this superior to other castable refractories:

• After pouring your mold and removing the master, the mold can be forced dried in a kiln and you will be ready to fire your piece in a matter of hours, compared to waiting days to air dry.
• Renders very fine detail when casting detailed relief.
• Does not break down after a few firings as with existing castables.
• No glass separator is required for slump-over molds.
• Simple to prepare as plaster of paris. Just mix 50/50 by volume with water, pour and fire. Finished mold can be reworked with a file, scraper, etc.

1. Notice: this process is very complicated and the below instructions are a simple guideline.
2. Always wear a respirator when working with any refractory product even though this product does not contain asbestos.
3. Determine the volume of MOLD material needed (approximate 50/50 by volume - material to water).
4. Have your master mold totally prepared with mold release applied.
5. Add mold mix to water and mix to desired consistency by hand for small molds. For larger molds, use a drill and mixer. The total working time is approximately 10 to 12 minutes. Longer working times can be obtained by using slightly more water to create a looser mixture.
6. After pouring, vibrate out trapped air or poke the liquid with a small stick all over, but gentle so as not to damage the master mold.
7. Set-up time is 20 to 30 minutes (or longer). Remove master mold.
8. Dry completely before putting in mold in kiln
   • It is important to completely dry before using
   • Crack lid 1/2"
   • Ramp mold to 200 degrees F (water turns to steam at 212 degrees F - so we are drying just below this temperature)
   • Soak for 2 hours
   • Turn off kiln and let cool naturally
   • Add your glass
   • Crack lid 1/2"
   • Ramp up 400 degrees per hour to 1000 degrees F
   • Soak for 2 hours
   • Close Lid
   • Continue to heat to the temperature you will fire your glass to.
   • When done, cool very slowly to prevent thermoshocking.
9. The finished mold can be reworked if you have changes, use files, drills, scrapers, etc.
10. The less you handle the finished mold the longer it will last. Allways place large molds on a kiln shelf and move it resting on the shelf.