As I build, holding the barrel in place, or clamping for Acraglas, I use Velcro strips. You can get a roll of them at any big box store as they are used as cable and wire wrapping. (One side is the hook, the other side is the loop, so no adhesive) They are cut to length already, are reusable many times, adjustable and about a penny a piece. They work well "strapping" any parts together.