: I am in the habit of using a rubber mold for making my facets but the best way is to warm up the lap until it's starting to move and push a stick or other item into the lap and then put the mirror on and level out the lap. John Dobson uses a corner of a 1x2 after letting the lap cool a little bit and then presses the lap again. The pitch is still flowing pretty well at the temps that he does the grooves and puts them all the way down to the tool. The grooves will shrink when you put the mirror on the lap so make sure that you make a big enough groove. Also making more grooves will help in speed of work of the lap and in keeping the pitch from closing up so fast. : Pitch will flow if you work slower than a certain speed and then crack if you work faster than a certain speed, just like silly putty, and the proper consistency is about that of silly putty for making the facets. Also, you want to push the facets up into little mountains rather than just raising the edges.

Where can I get those rubber molds that you mentioned earlier? thankyou!

• Re: Cutting Chanels in My Lap - bobmay - August 25, 1999 - 02:42 UTC