Here's a quick, easy way to simulate a cast metal texture on models of tanks or similar subjects. The model in this case is Italeri's 1:35 M4A1 Sherman, which had a cast hull but which is moulded by Italeri with a smooth and downright shiny finish! I used Perfect Plastic Putty thinned with acetone nail polish remover, and applied with a dabbing motion using a cheap old paintbrush, avoiding areas which were made of rolled or machined metal.
I recommend thinning the putty until it's quite runny. Let it dry throughly before priming or painting. If some spots turn out too raised or lumpy, it's easy to sand them down and re-apply the putty. Worth a try!
