My caulking guns used to accumulate gobs of hardened caulk and mastic on the plunger, making cartridge removal very difficult. The tough rubbery mass (silicone is the worst) was a real nuisance, and prompted the early retirement of several guns. Then I discovered the trick of spraying some silicone lubricant (WD-40 works too) on the plunger and into the back of the barrel. The lubrication lets the encrustations peel off in one piece, and makes changing tubes easy. You’ll have to renew this lubricant every so often. One warning, though: If your gun has a friction-type drive mechanism, don’t spray it — the lubrication will render it useless.
—William H. Brennen, Denver, CO
Edited and Illustrated by Charles Miller
From Fine Homebuilding #25
