Re: [ATM] First Pitch Lap - any tips?

[Michael Lindner <mikell@optonline.net>]

On Wednesday 09 June 2004 05:01 pm, Guy Brandenburg wrote:
> I may experiment with parchmenbt paper and see if it
> is really much better than ordinary paper for this.

I think I'll try this also. Any issues with getting the parchment to conform? 
It's rather stiff compared to foil. FWIW I was an "early adopter" of the 
"Perfect Pitch Lap" (which is at 
http://home.comcast.net/~kevin_mccarthy/Pitchlaps/images.html).

Although it produced beautiful laps I had some difficulty. If the overhanging 
parts of the mold aren't supported properly, the centers of the facets bugle, 
causing dimples that are hard to press out. Also, you have to pour quite a 
bit of extra pitch to make sure the "overhanging" squares are filled evenly. 
Perhaps Kevin has addressed some of these issues since I tried it.

This is not meant to say that it doesn't work, it does. It's just that I found 
it easier (for me) to do it "the old fashioned"way. Well, not *too* old 
fashioned - I think Texereau's pitch square method is way too much work.

Lately I've been pouring pitch on the tool with a blue painter's tape dam 
around it, stripping off the tape, pressing the mirror (lubed with a thick 
dishsoap, water and CeO mix), then channelling with a tire grooving iron.

Clear skies.
-- 
Michael Lindner
http://www.starastronomy.org *** http://home.att.net/~mikel
http://www.atmsite.org *** http://www.atmlist.net

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