Cast-a-Mold 30TF
Made in the USA
Made in the USA
When you buy from SRC, you'll receive fresh American-made materials every time, direct from the source.
Cast-a-Mold 30TF, faster and slightly harder than Cast-a-Mold 25T, with excellent tear strength and gives accurate detail reproduction.
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Cast-A-Mold 30TF is faster and slightly harder than the Cast-A-Mold 25T. It is a general purpose rtv silicone elastomer which exhibits excellent tear strength, long library life, and accurate detail reproduction. Cast-A-Mold 30TF is a condensation cured silicone (tin catalyzed ) It is used to make rubber molds that can be used to cast polyurethanes, epoxy's, polyester's, cement, concrete, soap, wax, plaster, etc.. It is easy to mix and de-air, and will cure at room temperature over virtually any surface. Cast-A-Mold 30TF is extremely useful for applications where superior physical properties are required.
| Mix Ratio | 10:1 by weight |
| Working Time | 15.0 minutes |
| Demold Time | 8 hours |
| Heat Tolerance | 300°F + |
| Tensile Strength | 600 psi |
| Elongation | 500% |
| Tear Resistance | 150 ppi |
| Color | Blue |
| Hardness | 30-A |
| Viscosity | 30,000 cps |
So, I purchased this while experimenting with polyurethane manufacturing. It's a tricky business, I'm learning. . . .
Since February of this year, I've tried the Flex-it 40, Tough-Cast 65D Black, Tough-Cast 75D, and now the Cast-a-Mold 30TF. I feel I've given this company's products a pretty fair shake. And, they have all performed flawlessly.
Yes, measuring carefully by volume or weight is VERY important, this is chemistry class after all. Measure wrong, results are wrong. . . while they may still work, they will vary from the specifications provided on the finished product.
This product (Cast-a-Mold) finishes in what looks like some kind of milky blue color. It is soft to the touch and looks like the object on the roof of the car in the movie Idiocracy. It is fairly heavy in weight, but flexible, and durable enough that I was able to pull a Tough-Cast 75D product out of the mold after forgetting to spray it with silicone (idiot move on my part).
I tried a similarly specced product I found on Amazon from a company called BBDINO. It looked ready to rock and roll and all, was a solid and medium blue color (like the add to cart buttons on the site today, 7/23/2025), but it refused to cure anywhere that it touched release agent that was sprayed in from an aerosol can.
Alternatively, the SRC product just keeps on working, each and every time I try it. Recommended and I'll likely not stray from this product going forward. Value, quality, consistency of results, and American made are where it's at.
Should have started with this in the first place if I had known about it.
Great product! Good value and quality mold making material. The molds came out great and they will last a long time.
Cast-a-Mold 30TF is easy to use for beginners and captures fine detail. I had 2 out of three of my first pours turn out perfect. On the third I used Pol-Ease 2500 and likely put it on too heavy as that pour resulted in a mold with a texture full of bubbles and funky waves. I chalked that up to operator error and bought another bottle of Cast-a-Mold to complete my project. No degassing was required and I did all the work in my kitchen.
Easy to use and worked great for concrete molds.
