Model tips

I make models for 25mm or 1/72 scale. I use all sorts of things to do this. Plastic sheeting is one of the things I use. I get it from all sorts of sources. I cut it to size with a razor knife. I use weed eater string for rivits cutting it into small slivers. I sculpt what I need to complete the model, which in many cases is quite a bit of sculpting. Once I have it complete I usually make a mould/mold of it. I use RTV silicone to do this. It can be found in many places. I place all the pieces in a box, glue if necessary, spray with release and pour in the RTV. I then use a 2 part urathane to cast the pieces. I use a seringe to inject the mould/mold so I get all the detail and no air bubbles. The urathane hardens in 3 minutes so everything must be ready. One more thing water is the enemy with urathane. You never want to have water in the mix. Wood, paper, and metal objects all retain water. Seal them first with paint before you make the mould/mold of the model. As for how to cast a certain model, well that is hard to explain. You have to realize air will get trapped in a mould/mold if it has many undercuts or long thin pieces. I get around this by trial and error. I also cast the model in pieces to avoid this. Much of what I make is flat cast and I put it togeather after I cast the pieces. The only way to avoid air is a vacume chamber or injection process. I do all of my pieces without either one. As I make pieces I figure out shortcuts, and processes, all of which you just have to figure out on your own. For some reason no one shares this information and it is hard to figure out some of the tricks, but in time anyone can. It is a long process, but when no one else makes the pieces it works. I can explain any details if you care to try your hand at a special bit you want. My email is modelersattic@yahoo.com