- Written by Daniel Livingston
I've decided to put together a basic "how-to" guide that covers making liquid silicone molds and plastic resin molding and casting . I learned quite a bit over the last 5 years about silicone rubber while building my B9 Robot and more than 35 Twilight Zone Mystic Seers replicas. Hopefully you will pick up a few tips here that will help you avoid some of the pitfalls.;; These silicone rubber mold making tips can be used by the hobbyist who want to create molds for making chocolate, or to create soap molds and candle molds as well. When making food molds be sure to only use food safe silicone materials. If you wanted to know what is silicone or how to use it for molding, you have come to the right place. I've added links to most of the necessary supplies where available at Amazon.
If you're going to get serious in molding, you'll want to purchase a vacuum pump. I got mine on ebay for about $100. It's an industrial pump and it is very rugged. You may want to buy one of the smaller hobby vacuum pumps available, but I went for the commercial one as it should last me longer, and it actually cost about the same. You want one that can pull 29 "inches of mercury" for a complete vacuum. There are several on Amazon that should do the trick.
First, a few things you'll need. Get yourself a good 400+ piece basic set of LEGOS. Yes, I said LEGOS! If you're lucky you have a son that went through the LEGOS phase. If you're like me, you may still have yours from when you were young.;; Either way, they are a must if you want to quickly make molds of various sizes. You want a set with just the basic pieces and none of the fancy special pieces. Your best bet might be hitting up a few garage sales. The smallest set I could find on Amazon was 650 pieces which is probably more than you'll ever need. Don't just count pieces included in a set as most of the smaller specialtity piece are of no use to you. You want to make sure you have plenty of 2x4, 2x6 and 2x8 pieces. The "LEGO Bricks & More Builders of Tomorrow Set 6177" is as good a starter set as you can get, with no specialtity pieces.
You may want to pick up one of the "starter";molding liquid silicone rubber kits and plastic resin kits. I have tried kits from both Smooth-On and Por-a-Cast. Smooth-On has what they call "Super Sampler" kits that contain enough rubber for several small molds and dozens of small resin parts. I placed links to several kits in my;