Window glazing that will stay put

Q I have little success with glazing material such as putty and the like on our wood windows. In two or three years the compound begins to fall out. Do you know of a product that would give better service?

A reader San Francisco

A One ''do-it-yourselfer'' uses a caulking compound to fill edges and holes. He uses a small amount of the compound to hold the glass in place. Then he uses the caulking compound over the top of the first application.

He applies a small bead, spreading it smooth with a putty knife. The result remains pliable, he reports, and avoids the weather cracking problem associated with glazing compounds. And he's from Phoenix, Ariz.

A veteran professional glazer says that one of the best glazing compounds is DAP No. 1012. It meets federal specifications and does not set up as hard as some other conventional putties. Even DAP, however, may suffer the consequences of several severe seasons.

One technique the veteran glazer uses is first to remove the old putty and brush out any powder in the sash. Then he applies silicon with a caulking gun, laying a small bead against the glass and sash. He allows it to set up for at least three days. He follows with DAP No. 1012, beveling it with a putty knife.

In time, should this compound crack, the silicon below will protect against leaks.