As I was reading the instructions of the casting materials I bought, it started to look like latex moulds could be used for resin casting. Of course I had to try it. For the experiment, I chose making castings of the Hollywood Royalty Lana Turner's feet. Plaster castings of that size are not very durable, so I thought it would be great to have them made of resin.
The earlier blog post about making foot lasts can be found here. This time I was using latex meant for making tubular moulds, so it worked a lot better.
When I made the latex moulds, I made small tabs on the back, so it would be easy to hang the moulds from the clips in my magnifying glass. Hanging them helps to keep the correct form while the resin hardens.
I treated the insides of the moulds with form releasing wax to protect the latex and to help remove the castings. I'm happy to say that the casting was successful and I now have resin foot lasts for Lana. There was an air bubble in her left big toe, so that's a small flaw, but it does not affect the usability of the lasts.
I also made some resin shoe soles using latex moulds. Unfortunately, the latex seems to deteriorate very quickly when used for resin casting. It can be used, but I didn't manage to make very many castings with one mould before holes started to appear. That could be due to not having just the right kind of form releasing agent. There are so many different varieties that it is hard to know, which one should be used. I used what I happened to have and it was the wax I bought for making and using silicone moulds.
I'm currently writing the chapters about mould making, casting, and doll feet, so this was part of the experiments I'm doing to figure out what needs to be included in the instructions. Doing it all as I'm writing also helps to remember things that have gone wrong and to find out new things that can go wrong, so I can include tips for avoiding those.