Author Topic: Broken Mirror Repair ( ST1100 ) *  (Read 6555 times)

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Broken Mirror Repair ( ST1100 ) *
« on: April 05, 2009, 02:19:07 PM »
Original article can be viewed here:

Submitted by Mike Martin.


Broken Mirror Repair

Knowing what it costs to replace a broken mirror, I decided to replace a cracked glass myself.

I went to several glass shops in my area, and brought with me a convex mirror glass I had removed from a clamp-on mirror that I had picked up at Pep Boys for $8. After several stops, I finally found a shop that was willing to try cutting the glass. I gave them a paper pattern that I'd cut. Unfortunately, they ended up breaking the convex glass, so cut a flat glass and gave it to me at no charge. I decided not to use the flat one. Here's how I repaired the mirror myself:

1. Buy a suitable mirror assembly (or mirror blank) from the auto parts store. I took one of the ST mirrors into the store to try to find something with the same curvature. The one I bought had a black plastic housing with a pivot and clamp.

2. Purchase a glass cutter with a carbide wheel instead of a plain steel wheel. It cost me about $9 vs. $2.50.

3. Cut the housing apart using a Dremel tool to free the glass.

4. Make a pattern using a piece of plain paper. Cut a small hole in the middle of it, about 1/2" square. Attach the paper to the surface of an unbroken mirror, using masking tape across the hole. Mark the pattern as "right" or "left", depending on which mirror you are using to make it. Carefully form the paper around the perimeter of the glass, forcing it into the crevice formed where the glass meets the housing. Mark this line with a sharp pencil, remove the paper from the glass and cut along this line. This pattern will work for both right-hand and left-hand mirrors, depending on which side of it is laid against the glass.

5. CAUTION: Use hand and eye protection when working with the glass! You must firmly support the glass when scoring it with the glass cutter. I used a domed plastic lid made by Bucket Boss for use as a seat on a dry wall compound bucket. I laid a folded towel on it to cushion the glass. Tape the pattern in place to the face of the glass through the hole. One edge of the new glass closely matched one side of my pattern. I decided to score around the other three sides of the glass, but wasn't sure I would be able to make my cut follow the corners exactly. I decided to leave a small peak at each corner. The first score went in a gentle curve following one side of the pattern (except at the corners) from one edge of the glass to the opposite edge. Remove the waste piece by gripping the waste portion near the scored line with pliers and bending away from the scored side. (It's a good idea to break it under a cloth, to contain any flying shards should the glass shatter.) Score and break each of the remaining sides in turn. Use a file gently to remove the small peaks at each corner. You can probably use some 240 grit wet-or-dry abrasive paper with water rather than the file. (The glass shop uses a wet belt sander for such work.)

Put a piece of self-adhesive plastic on the back side of the new mirror, like Honda does. This keeps pieces from falling out should the mirror get broken. Use a few globs of silicone gasket adhesive sealant to hold the new mirror in the Honda housing.

I consider myself lucky that it worked for me the first time. But even if it takes two or three tries, it's still worth it.

2001 M. E. Martin, All rights reserved
« Last Edit: December 18, 2012, 06:41:09 PM by Tom Melnik »