I am thinking about doing some casting in resin and not having done any before so I am looking for some advice on whats good or bad, dos and donts. What I need is a resin that can be machined or drilled and can withstand some rough handling after its all set also something that will not take weeks to go off. Its for a one off piece of a large scale model Im building and will be made from a one hit (or possibly two if my luck hangs out) mould which brings me onto the question would I need some type of release agent applied to the mould?
There are no big secrets to mold making and casting.
First of all you will need to decide if you are going to make 1-part or 2-part mold. 1-part molds are the easiest and I do them constantly to make bases for Kits.
Best stuff I have found to make a box to make the mold in are LEGO bricks, yep, raid your tots toy-box.
What you will need:
non-drying Clay
vaseline
Silicon Rubber for mold making
Resin for casting
Rubber gloves
For both the Rubber and Resin try to get hold of stuff that mixes at a 1:1 ratio, easier that way and better results.
Next you will need to make a decision on Resin, they tend to come in different setting/curing times (faster = hotter) slower curing time also allows air bubbles to escape and thus get more into the fine detail areas.
There are a few sites online that detail the whole mold making and casting process or send me an e-mail and I can talk you through the trouble areas.