We also use Resin Rock, I have been using clear pro art die spacer from Ivoclar and it works great. It is always a good idea to exactly follow the manufacturers instructions regarding water to powder raitios because if you are using too much water it will change the density of the stone. So pretty...[More]

I agree with Melissa, the water ratio maybe too high. Dental die stone won't crumble unless the mixing ratio is way off, mixing procedure is not correct, or the stone is not being properly stored. I would also check how long the stone sets.When I did models long ago I poured them the night before...[More]

We use Resin Rock from Whip Mix and dva die conditioner from dental ventures of america.  Never have a problem.  Not sure who is pouring the models, but the water powder ratio is crucial.  :)