mark poulson Posted July 24, 2011 Report Share Posted July 24, 2011 I have made a master of sculpy clay, and I want to make a silicone mold. Do I need to seal the clay before I cover it in silicone? If so, what should I use? Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted July 24, 2011 Report Share Posted July 24, 2011 I found this tutorial that has a paragraph on sealing. Dave Quote Link to comment Share on other sites More sharing options...
mark poulson Posted July 24, 2011 Author Report Share Posted July 24, 2011 (edited) Dave, I found the paragraph, and it says fully cured Sculpy doesn't need to be sealed. I guess my next question is will I need a release agent? I plan to make an RTV mold of a swimbait with fins, a thumper tail, and a hook slot. I am going to use Alumilite 3 RTV. I made a mold of a similar, only larger, soft plastic swimbait, and it came out fine, with no release agent. But this master is hard, so I'm wondering if I need a release agent on it, and what to use as a release agent. Spray PAM is my default release agent for my POP molds, but I don't want to use anything that will interfer with the RTV curing correctly. Mark Edited July 24, 2011 by mark poulson Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted July 25, 2011 Report Share Posted July 25, 2011 I have read many times that the only thing that sticks to RTV is more RTV. In my experience this is not exactly true, I have had poured resin bodies pull a small chunk of RTV out of my mold when I have been a bit impatient demolding. Pam is OK with RTV, I have used it before, with success, but I have never used sculpy. The best release agents are those designed for RTV. I had a 'dry spray on' that I bought with the RTV, unfortunately it was a re-packaged shop brand, so I cannot help you with a product name. Are you going to seal the sculpy? I think it would be best. I always epoxy my masters. This gives a smooth finish that the RTV cannot get a hold on. I guess it depends on how smooth the sculpy surface is. Hopefully you will get more 'first hand' responces, if not, more Google reading. Good luck and I look forward to seeing the pics. Dave Quote Link to comment Share on other sites More sharing options...
MuskyGary Posted July 25, 2011 Report Share Posted July 25, 2011 Question, Do you bake the sculpy mold in the oven before casting it? or do you use the raw clay and just seal it? Quote Link to comment Share on other sites More sharing options...
mark poulson Posted July 25, 2011 Author Report Share Posted July 25, 2011 (edited) Question, Do you bake the sculpy mold in the oven before casting it? or do you use the raw clay and just seal it? I baked my clay so it's hard. I read on the Sculpy website that unbaked clay has sulphur compounds that interfere with the RTV vulcanization, and that you have to seal unbaked clay and use a release agent. I plan to seal my masters before I make the molds. I'll probably use either Krylon clear, or thinned D2T. I'm waiting for my RTV to arrive tomorrow to read the directions before I decide what to use to seal them. I'll keep you posted. Edited July 25, 2011 by mark poulson Quote Link to comment Share on other sites More sharing options...
mark poulson Posted July 29, 2011 Author Report Share Posted July 29, 2011 I wound up sealing my mold box and master with Krylon clear Acrylic. I poured two molds today, and I'll demold the masters tomorrow afternoon when I get home. I was amazed that two small molds, approx. 5"X1 1/2"X1 1/2" took the entire one pound jar of molding RTV. And I only made the mold boxes 1/4" bigger on each side, the ends, and the top, than the masters. That is some expensive stuff. I mixed the crap out of the two parts, so I hope everything turns out okay. I'll keep you posted. Quote Link to comment Share on other sites More sharing options...
mark poulson Posted August 1, 2011 Author Report Share Posted August 1, 2011 I pulled the masters out of the two molds I made this morning, and the molds looked great. I poured both of them and the baits came out great, down to my fingerprints on the tail. I plan to fish them this week, and see if the fish like them as much as I do. For what it cost me, I think I'll stick to caulking gun RTV silicone. It's a little more trouble having to make sure the silicone gets into all the nooks and crannies, but the Alumilite is too expensive. One pound barely made my two 5"X1 1/2"X1 1/2" molds. But I was able to get great detail with it. I'll post a couple of pics in the soft baits gallery. Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted August 1, 2011 Report Share Posted August 1, 2011 I have only had a little play with Husky's caulk molding method. What I found was that you could apply a thickish layer to the master first, before preparing the mold mix. Rub a wet finger into the layer, to speed up the curing process. This eliminated all the surface bubbles and the rest of the mold adhered to the cured layer. Worth an experiment at least. Dave Quote Link to comment Share on other sites More sharing options...
mark poulson Posted August 1, 2011 Author Report Share Posted August 1, 2011 Dave The wet finger is a good idea. I'm going to try that next time. Quote Link to comment Share on other sites More sharing options...
EdL Posted August 1, 2011 Report Share Posted August 1, 2011 Then watch what you do next with that wet finger. lol Quote Link to comment Share on other sites More sharing options...
RayburnGuy Posted August 1, 2011 Report Share Posted August 1, 2011 Then watch what you do next with that wet finger. lol Yea Mark. Don't be giving your kids any "wet Willies". Ben Quote Link to comment Share on other sites More sharing options...
mark poulson Posted August 2, 2011 Author Report Share Posted August 2, 2011 Now you warn me! How do I get silicone out of my nose without ripping out all the hair? Quote Link to comment Share on other sites More sharing options...
EdL Posted August 3, 2011 Report Share Posted August 3, 2011 Just let the hairs grow out and trim it off. Holloween is just around the corner so tell everyone your getting your costume ready early if they start asking or run away grossed out. Sorry everybody to side track this thread. Had a brain phart and couldn't keep my fingers from typing something stupid. Quote Link to comment Share on other sites More sharing options...
mark poulson Posted August 3, 2011 Author Report Share Posted August 3, 2011 Just let the hairs grow out and trim it off. Holloween is just around the corner so tell everyone your getting your costume ready early if they start asking or run away grossed out. Sorry everybody to side track this thread. Had a brain phart and couldn't keep my fingers from typing something stupid. Hahaha!!!! Quote Link to comment Share on other sites More sharing options...
