A way to leakproof glazed windows

Q. The glazing compound on our casement windows often cracks and loses its seal, thus allowing leaks after a short time. Is there a glazing compound that adheres better than the old stuff? Is there a glazing material which can be extruded from a caulking gun? Jerome C. Sisson Sandwich, Mass.

A. a veteran window 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 conventional putty. However, even DAP may suffer the consequences of several seasons and crack some.

Another glazing material is silicon caulk, available in tube form, which lasts longer than putty but cannot be forced on a bevel in the window sash itself.

A third option, whether or not the sash is wood or metal, is this:

Remove the old putty and brush out any powder in the sash. Then apply silicon with a caulking gun. Lay the bead of silicon against the glass and sash. Let the silicon "set up" at least 72 hours. Follow with a product such as DAP No. 1012, beveled with a putty knife.

In time the compound may crack but the silicon underneath will protect the windows against leaks.