AM 128 Silicone Rubber RTV 4.4 lb Kit

This stuff solids up pretty quick and makes great molds. First time using this product and it pretty straight forward. Just be sure to mix it well.

I paid for this stuff and from the picture it looks like a pretty good size that not the case its small and only good for one coat. it only come with one bottle of harderfor the price it should have at least two so i can get a second layer on my project likewise you will have more silicone then harder and they claim not to sell the harder by itself. that's not good( wanting you to buy more )other then the stuff working iti good if you like one coat and taking a chance of your one layer ripping when you take it off.

Buy their 1:1 mix, it makes a x1000000 more sense. WTF is 12:1 ratio ...with no specifics to measurement by liquid ? Their included instructions are a piece of paper. Not even a youtube video.

On the down side:The silicone is quite thick and relatively difficult to mix. Unwilling to invest in a strong vacuum system, I have attempted to remove problematic bubbles using a Foodsaver vacuum device and hard plastic Foodsaver vacuum containers. This setup does not do an adequate job of degassing this silicone, and bubbles in the final mold are a problem. The silicone is best left to vulcanize overnight, so not good for time-sensitive projects.On the up side:Molds produced with this silicone are very strong and durable.I believe the manufacturer sells a accelerator which can speed up the vulcanization process.If you already have a proper 29"Hg vacuum setup, you will be unlikely to have the same bubble problem I have.If I ever were to buy a vacuum pump and chamber, it would be highly likely that I would purchase more of this silicone. Without it, I am unlikely to use the rest of what I have.

You must use a digital scale. It works with a ratio of 10 to 1. I've used it on 2 projects so far. Spray a mold release on your project, generally 2 coats. Take a chip throw away brush & cut the brush down & spread it on. First coat should be heavy but not running off. Wait 24 hours to apply the second coat to cover any areas that are light. I fiberglass over the second coat after 24 hours with a mold release between the fiberglass & the pink silicone.I don't know what people are doing wrong but I love the stuff. It's a bit pricey, but you have to pay for quality.