The Pitch Lap

This was a learning experience. The first thing I learned is that there is an incredible number of ways to create a pitch lap. After carefull consideration, and lots of discussion, I went with this route.

I happen to have had an extra ¾ inch glass blank laying around from previous trepanning exercises. I decided to use this blank as a pitch lap substrate.

I had observed the local mirror making group create a couple pitch laps, and to me it seemed like a really good idea. They were kind enough to offer to help me pour the lap. Here’s how it went.

1. The mirror was washed and dried
2. The mirror was placed face up on a table and covered in a slick slurry of CEO
3. On top of this was placed a ¼ inch thick piece of rubber with 3/8 inch holes punched thru it creating a grid
4. The rubber mat was covered in a slurry of CEO
5. The Glass blank was washed, dried and wiped down with turpentine
6. The pitch pot was warmed up
7. Starting in the center of the mirror/matt pitch was poured in concentric circles working from the center to the outer edge
8. quickly, the glass blank was placed on top of this to form a glass/pitch/rubber/mirror sandwich
9. After a few moments the glass blank was lifted off the mirror with the attached pitch and rubber matt
10. The rubber matt was gently removed from the now firm pitch
11. the edges of the pitch lap were cleaned up.

The end result looks like this: (don’t mind the color, the lighting sucked)