How To Fix A Small Hole In A Glass Window

If you have to repair a BB hole in a glass window, you have two things working against you. The first is the inherent fragility of glass, and the second is its transparency. Unlike a hole in wood or metal, you can't just stuff in a filler and sand it flat — or can you?

Actually, you can fill a small hole in a window, but sanding is pretty much out of the question. There are several filling materials you can use, including clear nail polish (or clear lacquer, which is basically the same thing), two-part epoxy glue, or a commercial window hole filler, such as Permatex or Loctite Glass Glue. The basic procedure is the same for all materials, but if you use a commercial product, you can apply it directly from the tube. Otherwise, you're going to need a syringe without the needle.

The repair is practical only for single-pane glass. If you have a hole in a window with double-pane glass, you're better off replacing the window. The reason is that the hole has compromised the seal maintaining the vapor barrier between the panes that prevents condensation and provides insulation. Once the seal is broken, there's no way to restore the vapor barrier.

1. Clean Both Sides of the Glass

Put a few drops of dish detergent on a sponge and wipe down the glass on both sides to remove fingerprints, oils, and dirt. Wipe down the glass with a clean, soft rag and let it air dry.

2. Tape One Side of the Hole

Lay painter's tape on the glass to cover one side of the hole. If the hole was made by a projectile, like a BB, the entry hole will be bigger than the exit hole, so you'll want to tape over the exit hole and fill the entry hole. Make sure the tape sticks well to the glass around the hole; if it lifts or bubbles, the filler will seep out of the hole and make a mess.

3. Prepare the Filler

If you use a commercial filler, cut the end of the tube to allow the material to ooze out. If you use two-part epoxy glue, mix the parts on a spare piece of cardboard using a toothpick. If you opt for nail polish remover, suck a small amount into a plastic syringe with the needle removed.

4. Fill the Hole

Apply the filler into the hole using either the dispenser (for commercial fillers), a toothpick (for epoxy glue), or a syringe (for clear nail polish). The first application may not fill the hole, and if not, that's OK. Just let it stiffen and then add more. It's OK if a small amount dribbles out onto the glass, but you'll want to limit this excess as much as possible.

5. Scrape Off the Excess

Use a razor blade to scrape excess filler off the glass and to flatten the filler flush with the glass surface. This is easier to do before the material has completely hardened, but you should still be able to do it even if you wait too long.

6. Remove the Tape

Wait for the filler to harden completely before you remove the tape from the opposite side of the glass. Pull carefully; you don't want the tape to pull the filler out of the hole.

7. Polish It Up

Buff both sides of the glass with a rag and some window cleaner. If the edges of the repair are still visible, spread some white toothpaste (not the gel type) on the hole and rub vigorously with a soft rag. Use more glass cleaner after the toothpaste treatment.