Blue is a thread-locker for nuts and bolts that you don't want to fall off, but can
be removed easily. Red is a more permanent application for cylinder studs and
the like....things that are not normally removed, except in the case of severe
damage....like engine case replacement.

Green Lock-Tite is used for replacement bearings where the old bearing has spun
in the case, and the new one is too loose. It is the thickest of the bunch for
obvious reasons.

Lock-Tite turns to a plastic when it hardens. It hardens in the absence of air.
Any of these products can be softened with some heat, for removal.

All three are commonly used in motorcycle and small gas engine repair.

FBD.