alru19

Alright, I gave it a shot, but never was successful. Here is my list of how the polyurethane resin reacted to the plaster. Unsealad plaster:Poly adhered. Plaster sealed with Elmers: Poly adhered. Wet unsealed plaster: Poly removed easily but it had a bubbly surface. Unsealed plaster with vaseline: Bubbly poly surface. Sealed plaster with vaseline: Bubbly poly surface. Sealed plaster with pam: Bubbly poly surface. Plaster sealed with paint: Closest to success, but the paint came off on the poly. I ended up just doing what vodkaman said first and made a silicone mold. I am sure there is a way to do this successfully in plaster, but it definitely involves sealing the plaster so no bubbles get into the poly. Thanks all for the help.

Thanks gents. My original master is wood, and a very simple design. It's lathe-turned, so my 2-sided pop molds don't have any undercuts and removal shouldn't be a problem. But I have already made several pop molds of this wooden master, and don't care about ruining the plaster molds if infact they get lodged in there. I have decided to give the urethane resin route a try. I assume I will need to seal the plaster and use mold release so this resin doesn't stick to the mold? I plan on sealing the molds with elmers like I do for the plastisol, but don't know about mold release. Thanks again.

I am looking to make multi-cavity 2-piece pop mold, so I'm going to need multiple masters. I have seen that most people just make the multi-cavity molds by using plastisol baits as the masters, but I would like for a more rigid material that I can sand the seams off of. Is there any hard plastic that I can pour into a pop mold that will give me a rigid model that I can then sand and use to make more molds? Thanks.

I don't know of a mold but you could take a look at the deps death adder as well.