Ultracal thickness for foam latex
I’m starting to get back into foam latex and I found a method that I could use, and I’ve made molds before, just not for foam in a while. How thick should the ultracal be to avoid cracking? Thanks!
I usually keep my molds fairly thick, aiming for at least an inch, depending on the mold size. If you are worried about a mold cracking because it's large or the shape may make it prone to break, you can embed wooden supports in the ultraclal to help. You can also add reinforcing fibers like hemp or sisil to the ultracal (after you make your detail coat so the fibers are not on the mold surface) to strengthen the mold.
This course has a lot of great tips for making stone molds: