RE: [ATM] Dry Polishing?

["Thomas" <tomjan@ozemail.com.au>]

OK what I know about it, little tho it is, I'll gladly share.

Firstly the lap is made on the grinding tool, to which a layer of paper
is afixed, the paper should be made from fine cotton cloth and not have
any clay or other types of fillers such as you find in most modern
papers.

Secondly the polishing medium is very fine rouge applied as a powder and
dusted onto the surface the lap is then put into use. Like using pitch
slow steady strokes is the way.

A surface polished this way is almost as good as one done with ptich
it's just harder to figure the parabola into it, this might best be done
as a second operation with pitch. I can't say it this would save any
time or effort, but if you want to have a go, please let the rest of us
know how you get on. In the past this technique was only really used on
plate glass to the best of my knowledge, so pyrex might be another
matter, but I don't think it would be "that" different. It might just
take a bit longer?

Clear skies,
Thomas Janstrom
http://www.tjanstrom.com
http://www.norsewines.com.au
"Your nobody untill you've been ignored by your seventh cranio-facial
nerve."


-----Original Message-----
From: atm-bounces@atmlist.net [mailto:atm-bounces@atmlist.net] On Behalf
Of Jeremy Batterson
Sent: Saturday, 8 January 2005 6:27 PM
To: atm@atmlist.net
Subject: [ATM] Dry Polishing?


Now, Hughes is telling me that dry-polishing worked fine in the past,
for such a great one as T, one of the main fathers of modern
mirror-making. and I wonder whether there is an absolute reason why
pitch polishing need be better than dry-polishing. It T could make such
fine mirrors with dry polishing, why must we rule out such a method?
Mostly, because the pitch can conform more precisely to the curve, it
would seem to be better, but might it not be the case that dry polishing
would be fine for rough polishing? Methinks it would be easier to deal
with, for sure, without all the stick, and all. But who still DOES dry
polishing, and who can effectively answer such a question, who is not
yet long gone from this world? Who even knows how to do it, still? Who
is the live, flesh and blood person who can still answer this?

Jeremy D. Batterson
Ridgefield Park, NJ
(201)441-4888/(877)305-8856
Literary & Astronomy Page:
http://members.lycos.co.uk/jeremybatterson<http://members.lycos.co.uk/je
remybatterson>
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