Re: [ATM] Help me get back to sphere

["Ken Reid" <ken_reid@telus.net>]

----- Original Message ----- 
From: "Guy Brandenburg" <gfbrandenburg@yahoo.com>
To: "Rich Ball" <ShooterBall@hotmail.com>; "ATM List" <atm@atmlist.net>
Sent: Thursday, July 01, 2004 7:32 PM
Subject: Re: [ATM] Help me get back to sphere


> I agree with others that your pitch is too soft. Get
> it all off, and then boil it for a while and recast
> it. Be sure that it is relatively hard, first. Then

Hi All,

I've been tempted to ask this question, too, for some time.  My pitch lap
(made with a home made a Silicone II form: 3/4" squares, 5/16" channels) has
been trimmed once in fifty plus hours. (Gugolz 64 originally:) Only recently
has it warmed up above 65 F., but it has little affect on getting out of
Hyperbola land. (my third trip) It isn't difficult to get a  descent
Parabola either. It's just that every stroke suggested  for getting back to
a sphere digs deeper. Short TOT, Short MOT,  even TOT pabarolizing . I'm
chicken to go above 1/3 for turning the edge, again. With the warmer
temperature even chordal strokes on the 60% zone have little effect. So I'm
currently using TOT 1/3 and slowly cutting down the edge. It's a 10" f/6
plate glass, by the way. 1.75" thick. I've read Follet's treatise, so I
appreciate the edge active, historical implications of pitch lap action.
And, I press overnight using wetted Saran wrap between tool and mirror.

I've been thinking it's hard pitch. Got to be too hard. Now the thread is
soft pitch is the culprit. This topic 'hyperbola land ' seems to be avoided
like the plague on the list. Only 1 good reference in the archive. So, no
quick remedy? Simply, a long polish back with 1/3 TOT. Make a Tywann tester
and avoid all the experimentation? I think once people learn "the way" they
forget the numerous pitfalls they had to overcome, the details? Could the
tywann tester be a bulwark against this?  Sorry for the rant, I prefer to
shut up.

Thanks
KR




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