questions about custom mold casting

I have recently got into making molds and casting my own custom parts. I ended up using composimolds molding agent. No mixing just microwave and pour...long story short very good stuff.

My problem lies in the plastic. I got some clear 2 part resin which mixes 1:1. The molded plastic takes forever to cure. Like 48 hours and is still very "rubbery". The part that is left over from mixing sets up super fast and hard as a rock. If I were making coasters this shit would be awesome.

Any suggestions on what I am doing wrong or should I use up this crap while honing my skills and go with....(your suggested resin here) .

I just noticed I posted this in the wrong section.

Can a mod move this to customs section?

I've only researched casting, no hands on yet, but I'd definitely use what you've got to figure out how to avoid getting bubbles in the final pieces. From what I've read, the rubbery vs hard is determined by the ratio used in the 2 part resin, so maybe try a pair of 2:3 ratio casts, one in favor each part to learn if one ends up super stiff and brittle and the other like silly putty then adjust to your liking.

I would recommend smooth on prodocts like smooth cast 25
most are dyeable or clear they have a range of cure times I use smooth on 25 drys to finish in about 15 mins you can get them at smooth-on.com the even have a cool mold box calculator

Thanks guys.

I have gotten rid of bubbles thanks to needles. With the clear silicone you can stick the needle in and pull bubbles out. That and seriously the composimold sets up with a lot fewer bubbles than the others I have tried. If you screw it up you just melt and reuse.

I will check into the smooth cast as well. I am currently trying to change up my mix to see if that helps.

I like using the clear resin and adding a few drops of green. A friend said it helps with yellowing ib the future and if you add just enough you get a cool old glass coke bottle look.