Making custom molds for casting resin is quite easy when you have the right products! It’s very time-saving when you need to make many identical copies of an object. In my case, I had to make 8 golden rings for my Margaret cosplay. I could have made those out of Sculpey or any other baking clay, but sanding all those down would have taken ages. Making a mold also ensures that all the resulting pieces will be identical!
There are many products you can use to make custom molds, but Gedeo Siligum was the easiest to obtain for me so that’s what I ended up using.
- Quick hardening time
- No nasty smell
- Very easy to unmold resin
- Mold can be used many times
- Air bubbles are difficult to avoid
As you can see, my main issue with this product is that I always found air bubbles in the molds I made. For the 2nd and 3rd molds, I took extra care to press the silicone down on the original piece very well in an attempt to eliminate any air bubbles, but I was never successful. Fortunately, molds with air bubbles can still be used, but it means more sanding once your resin has finished curing.
How to use Siligum
- Get the piece that you want to make a mold of. Here, I made a flat ring with Sculpey. After baking, I very carefully sanded the ring until it was super smooth. This is important because any imperfection on your original piece will be transferred to the mold.
- Take equal parts of the blue and white paste. A digital kitchen scale is great for making sure you have exactly the same amount of each.
- Mix the 2 pastes by hand until it turns an even light blue color, approximately 1 minute. You have to be quick because once mixed together, the silicone hardens in 5 minutes.
- Place your original piece over a sheet of plastic wrap and carefully spread the molding paste over it. Try to carefully press the silicone down on the piece to eliminate air bubbles as much as possible.
- Flip the mold over and wait 5-7 minutes for the silicone to harden.
- Remove the original piece. Your mold is ready to be used!