REPAIRS : Open-and-Shut Treatment for Sticky Windows

It’s frustrating to have windows that stick, especially during the hot days of summer.

Most homes today have double-hung windows. These have two frames or sashes with panes of glass. The upper or outside sash slides down and the lower or inside sash slides up. The movements are controlled by pulleys with cords (or chains) and weights hidden within the frame. A double-hung window usually sticks because:

* It’s painted shut.

* Paint or dirt has accumulated in the grooves or on the edges of the moldings.

* Humidity has caused the wood to swell.

* The weatherstripping fits too snugly.

Here are some tips:

If paint has sealed the window sash to the frame, insert a wide putty knife--never a screwdriver--between the parting strip (the strip between the window frame and the sash). Work the putty knife up one side of the sash and down the other. You may have to tap the handle with a hammer to coax the blade in. If that doesn’t work, place a block of wood in the channel just above or below the stuck sash. Tap the block a few times with a hammer.

Once you’ve opened the sash and are able to freely move both sections, use a narrow putty knife or chisel to carefully cut away all the gobs of dried paint from the sash and parting strip. Sand the scraped areas, vacuum the sash channels, and lubricate them with stick paraffin, paste wax, hard soap, petroleum jelly or a spritz of silicone spray. Wipe off the excess.

If weatherstripping is too tight, lubricate it with a bit of stick paraffin or hard soap. If that doesn’t work, carefully remove and refasten it to allow more clearance. Don’t move it too far from the sash or you’ll negate the cold-air protection the weatherstripping provides.

A casement window, which is hinged on the side, operates by turning a crank and seldom needs repairs. If if becomes increasingly difficult to open and close a casement window, remove the screws from the crank assembly and inspect the gears. If they are badly worn, replace the whole assembly with a new one available from a window dealer. However, if the problem is caused by old, hardened grease, wash the assembly in solvent and re-lubricate with fresh grease.

Make sure that the operator arm slides smoothly in its tracks as the window is opened and closed. If it doesn’t, remove and straighten it. Or clean out the accumulated debris. Then apply a generous dab of fresh grease and reassemble.

If you feel a draft with a casement window closed tightly, adjust or tighten the locking handle. Or install a thin layer of self-adhesive foam weatherstripping between the sash and the frame.

Though some sliding windows are made of wood, most are aluminum. They move along a closely fitted track at top and bottom. If you have trouble sliding the sash or storm window, remove both as well as the screen. Clean out debris and clean the metal weatherstripping, its groove and the edges of the storm window and the screen.

Apply either stick paraffin or paste wax to the edges. Then reinstall the three components in the reverse order that you removed them.