Tuesday 24 September 2019

Making molds part 1

I started molding and casting 10 years ago. I did this out of need for parts that I had built or made modifications to so that I only had to build one really well. Then a mold can be made from the master and duplicate parts can be made from that mold with poly resin. I normally use Smooth-on silicone rubber and urethane resins. Here I am going to introduce you to a product that I use if the detail is not critical or intricate and especially if you will only need to use the mold once or twice. This product is called   Composi Mold . The nice thing about this product is that it can be used and then remelted to use again on a different pattern. I used it to create this wall from a Walthers building that I bought at a swap meet and then found the wall missing. I had the wall from a kit I had bought so I thought I would just cast a new one. The thing to ponder here was that this would be a lot of rubber for just one use but I then found Composi Mold at an art supply store in Edmonton. I did some tests and the detail was pretty good. I didn't use mold release on this particular mold as I did not know how it would affect the product when reusing it.  The wall on this building faces to the back of the layout so any small imperfections like those noted in the windows would not be seen anyway. I followed the instructions heating the material in the microwave and gave it a bit of time for some of the very small bubbles to pop out. It has the same consistency as melted honey when you take it out of the microwave.  The pictures below show the master which is brown and the white resin finished cast.  This mold captures the detail that I was hoping for.

Below is the mold and the casting. The mold has since been remelted and reused.