Pipe Clamps

A pipe clamp puts the same fixed-foot-and-sliding-jaw mechanism as an F-clamp onto ordinary black iron or galvanized plumbing pipe instead of a dedicated bar -- buy one set of clamp heads, then buy pipe cut to whatever length a given glue-up actually needs. That makes pipe clamps the cheap way to get real length for wide panel glue-ups, where a purpose-built bar clamp of the same reach would cost considerably more.

The tradeoff is bulk and weight -- pipe is heavier and less rigid than a dedicated clamp bar, and a long pipe clamp can sag or roll more than a parallel clamp built for the job. For occasional wide glue-ups, that's a fair trade for the price; a shop doing them constantly often graduates to parallel clamps instead.