Those of us who work on small engines will know the pain of inserting plain circlips (the ones without tabs to compress them) into fresh pistons. The way forward is clear enough, you just have to grip the clip hard with a pair of needle nose pliers and force it into the groove, but how to hold that delicate piston securely without ruining it?
Quite by chance I happened upon a very handy solution to this problem: You insert a scrap wrist pin into a bench vise, slip the piston onto the pin and tighten the vise. Compression will cause the pin to expand ever so slightly in one dimension, securely locking the piston in place with no risk of damage. I imagine this will come in very handy for cleaning ring grooves and the like, as well.
