- A staple in the glass casting community
- Widely recognized as the strongest mold material available for glass casting on the market today
- The glass caster's best choice for large pieces or configurations that will place significant stress on the mold material
Package size: 50 pound
Made in the USA
7 Reviews Hide Reviews Show Reviews
Having used several refractory mixes over 20 years, this product makes for a convenient pre-mix used in most applications. However, in some specific uses, it can be troublesome. The heavier particles settle to the bottom during shipping and create an uneven mix if used without remixing. Also those same particles can settle in the wet mix as well as the flask, forming a weakness in the mold wall as well as in some cases binding to the glass. Where as this is a poured mold and cannot be hand built, the mold can be excessively thick in areas making cold regions in the mold. R&R 910 should be used mainly for crucible casting and is not always recommended for frit fusing. Sometimes good old 50/50 is all you need .
My work flow is to sculpt in clay, 3D scan, 3D print, and do lost plastic casting in glass. Glass-Cast 910 stands up to the drying, burnout, and casting cycles. I give it 5 stars.
I have already made several molds for glass casting and I really like this material.
It's much easier to use than Castalot or plaster - and seems to produce very nice molds.
I really liked the calculator for determining water and investment ratio.
I'm mixing with a mixer on a drill - that works well.
On one of 4 molds I made yesterday I tried to push the mold out of its plastic container too soon - and the mold cracked. The other 3, where I waited a bit longer were just fine. You may want to mention that letting mold set for at least 1/2 hour improves quality in your usage notes.
Overall I found your usage notes very helpful but I am still learning some stuff on my own.
I am casting both glass and bronze on an artist level and this pushes the upper limits. 910 never fails; it is strong and gives fabulous detail results every time. Stick to the water powder ratio carefully, make sure to use cold water.
Great product and technical support
I loved using R&R 910 and was thrilled with how it withstood over 514 hours casting time for the 29 pound piece I just finished. I didn't use a flask for this application, but threw on layers, each colored a bit differently, and because I was scared of leakage, dipped fiberglass cloth pieces into the investment for one of the layers. The fiberglass layer was probably overkill. This work was planned for one-time use but with the strength of the mold, if it hadn't had so many undercuts, the material would have withstood more castings. It left a really clean finish on the glass and the only clean up I have to do is to clean up my mistakes which were many. I liked it so much I ordered 100 pounds more!