biggamefish Posted June 6, 2014 Report Share Posted June 6, 2014 Anywhere I can get some custom made aluminum molds made for pouring urethane resins? The silicone rubber molds tare up after 25-30baits Quote Link to comment Share on other sites More sharing options...
robalo01 Posted June 7, 2014 Report Share Posted June 7, 2014 I know this isn't exactly what you are asking... 1. Don't give up on rtv too quickly. You might want to try a harder formula first. They tend to last longer. 2. When you make an rtv mold you are proud of, make a template of it with your casting resin (a mold of the mold) then you can copy it as many times as you want. This way the you work with several molds. Heat is wears them out. If you ley them cool down between pours they last longer. You speed up production and when one wears out you can pour a new one overnight. 2 Quote Link to comment Share on other sites More sharing options...
Richard Prager Posted June 7, 2014 Report Share Posted June 7, 2014 (edited) I've bought the finished product. great guy to deal with..... https://www.youtube.com/channel/UCXLmPw2p5vjfE2dQH8OTINg LMAO....should have scrolled down further....there he is! Slav is a great guy to deal with and fast! Edited June 7, 2014 by Richard Prager Quote Link to comment Share on other sites More sharing options...
biggamefish Posted June 7, 2014 Author Report Share Posted June 7, 2014 Robalo thanks for the tip I never though of that, any tip on how to make a copy of the mold? Quote Link to comment Share on other sites More sharing options...
wchilton Posted June 16, 2014 Report Share Posted June 16, 2014 (edited) I've played with silicone molds for soft plastic and learned a few things. I'll just throw out some info and you'll have to experiment a bit to see if any of it is useful for you. First (and possible easiest solution for you) is that silicone rubber has a certain amount of silicone oil in it which can get depleted over time. Since urethane loves to soak up oil it could be that your urethane pours are depleting the natural lubricant in the rubber mold. I try applying some 100% silicone oil to your mold (one that's been used for several baits but hasn't yet been damaged) and see if that helps. You could wipe some into the cavity and leave it for a while/overnight and I think you'll see it soak into the mold. Make sure whatever silicone oil you use is 100% silicone. There's some available as model railroad lube (small bottles) and you may also see some sold as "rtv softener" for rtv silicone. Since you're not pouring HOT plastic, you might even be able to get away with silicone oil that has some solvent in it (like tire shine silicone) but use at your own risk! The next trick I've learned is to use ground up silicone from old molds as a filler for a new batch. I started out just using cut pieces (cut with knife or scissors) but found that if I cut the old mold into smaller pieces and add some silicone oil for lube I can grind it up in an old blender. Then I mix to ground up silicone into the new RTV after the new stuff has been thoroughly mixed with hardener. If you do this, make sure the new silicone/liquid is the same cure-type as the old/solid to avoid any compatibility problems. The most common two-part silicones are tin-cured. There's also a platinum cure RTV that's supposed to be a bit more durable but also somewhat more expensive. Not sure if that would help you out. First thing I'd try is some 100% silicone oil to maintain the release properties of the mold/molds you have. By the way, be sure and test to make sure you can clean all silicone oil off your hard baits before using it on your mold. It could cause problems with paint sticking. That's never been a problem for me with soft baits. Edited June 16, 2014 by wchilton Quote Link to comment Share on other sites More sharing options...
robalo01 Posted June 16, 2014 Report Share Posted June 16, 2014 How did you make the original mold? Pour silicone over a hard master? The original molds are made from a hard master. including all vents and pour-holes. See any of 500 tutorials on youtube Place your two halves cavity up on a flat and level surface. Make a mold box around them Pour your hard plastic over them (give it a good 1/2" thick at the thinnest point over the edge for a sturdy mold. When it hardens and cools, turn it over on pout silicon into the cavities Make all the copies you need. Quote Link to comment Share on other sites More sharing options...
