Hi E,[/size]Well he I go, this is just my way of doing cold casting and this posting does not give all the tricks of the trade or is a detailed method, but hope it helps ?[/size]First , the silicon rubber or RTV .... I use is "Shore 24 " and the casting resin is "Fast Cast"Both which I order from CFS in Cornwall. There are others RTV & Resins on the market, but I have found over the years this to be the best for me.When you first start its best to start with a simple master, i.e door, lockers etc. As I've said before in my build log, when making a masters , make the best you can, as any mistakes will be repeated on each casting taken.When making the master, I always think about how I get the casting out of the mould In one peace. The shore 24 RTV is flexible and allows me to get some quite complicated masters out , however You could make a split mould.The mould box Method I use is to use draws from an old tidy all, but I do make boxes from 20 thou plasticard. Some others used Lego bricks with go effect. Note always a fix the master to the base of the moulding box , as some fittings can and will float to the top when being moulded if there not fixed down.When I make a master I usually use plasticard , brass or automotive body filler as seen in the picture 1. of the sat dome.Some complicated items like the 30mm Gun mount . I build in a kit form and then moulded each component separately , see picture 2. As I said before , the additional detailing is based on lots of actual photos of the Gun.I do use the model drawings for the general measurements, but the detailing is based on photos of the actual component being replicated.Now a days you can buy plastic, Alli and brass hexagonal , angle, half round etc sections in differing sizes, these section I use to add detailing the fittings or making item like intake vents and doors as in picture 3,4 also see crane base earlier in this posting.Hexagonal section cut down to represent nut/bolts as seen in this picture 5 . Picture 6 is one of the lift raft units.