Re: [ATM] Raised zone

["Jerry" <wa4guu@verizon.net>]

I wasn't responding to this because I have already stated that I know
nothing about fixing TDE.

I was surprised when no one suggested that the raised zone 1/4 inside the
edge is a TDE.

I looked at the mentioned link... It showed 3 methods. We could call the
fingertip method to be number 4.  there is a 5th method. Bob May has a
stroke with pressure on the leading edge of the lap. Lets call this number
5. There is a number 6 that no one is willing to try, except for me.

The problem with the "raised zone" being so close to the edge is that what
fixes it can make it worse. The raised zone was one inch wide and now it is
1/4 inch wide.  It was easy to work on when it was one inch wide but now it
is not easy because it is so close to the edge. 

Matheus said he used Texereau's method, but I'm not sure which one. On the
page he linked to, number 3 might be what he meant. Or he may mean MOT long
strokes with little side motion adding correction in the outer inch. The
result was that he shortened the radius just slightly inside the edge to
more closely match the curve inside the raised zone. The action has not been
carried all the way to the edge, and certainly not off the edge. So there is
a crest 1/4 inch inside the edge.

Oh.  I almost forgot to say what method number 6 is. Pretend now that the
mirror was 1" larger in diameter. The "raised zone" is now starting 3/4 inch
inside the edge and extends to the edge. Continue with method number 3 on
the linked page. Start with the pressure just inside the pretend "edge"
which is now 3 1/2 inches from the center.  If you think that I am crazy you
are right.  But so is Texerau.  Look at his figure on retouching defective
zones. That is Fig. 42 page 92 in my second edition. Look at numbers 6 and 7
in that figure. Notice that number 6 bottom is with knife a little farther
from mirror and simplifies retouching by treating it as a raised edge.
Pressure is on the overhang side of the tool and the work is TOT. If you
insist on working MOT you can achieve the same result pressing on the side
of the mirror NOT overhanging.

As you can see, if you believe Texereau, (I do) opposite techniques can
produce the desired result. How can you go wrong?

Jerry




-----Original Message-----
From: atm-bounces@atmlist.net [mailto:atm-bounces@atmlist.net] On Behalf Of
mjlazo@ifsc.usp.br
Sent: Thursday, May 25, 2006 5:40 PM
To: atm@atmlist.net
Subject: Re: [ATM] Raised zone

Tanks Mark, Jim and Bob,

I am thinking in try to use the finger tips to to remove the raised zone but
i
am a bit afraid because Texereou book do not recommend small polissing tolls
for zones higher than 1/4 wave. If it do not work i will try the method 2
for
TDE suggested in the link bellow
http://members.aol.com/making%20a%20mirror/page23a.htm
tanks again,
Matheus






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