Re: ATM 10" help - TDE?

["Tyrone Steele" <atm@pivotmusic.com>]

This is actually much more helpful infotmation than just the general brush
over.


----- Original Message -----
From: "Ken Hunter" <kb7h@onemain.com>
To: "Harold" <adams@rmci.net>
Cc: "Ken Hunter" <kb7h@onemain.com>; "Tyrone Steele" <atm@pivotmusic.com>;
"ATM" <atm@shore.net>
Sent: Thursday, September 26, 2002 2:38 PM
Subject: Re: ATM 10" help - TDE?


> On Thu, 26 Sep 2002 10:29:22 -0600 Harold <adams@rmci.net> wrote:
>
>      This means the overhang is on the forward stroke only?   Also, im not
> clear what you mean by steping sideways. Can you elaborate?
>
>
> Harold...
>
> My description assumes HAND WORKING with a barrel or other work support as
is
> typically used and before anyone complains...
>
> I know that it does not really work the way I describe. The glass does NOT
get
> pushed and dragged around. It is really being worked, abraded, polished
etc
> during the strokes but I find that when teaching beginners, it helps to
> visualize the action in this way and so far it has always worked for me.
>
> So to proceed...
>
> The pressure is applied on the outward going portion of the stroke and it
> helps to imagine that you are pushing glass uphill to the edge with the
center
> of the tool.
>
> Once you do 2 of these strokes, you will want to work the rest of the pie
> shaped segments of the mirror by side stepping around the barrel or work
> support and also use another axis of the tool so you will need to rotate
it a
> bit also...
>
> During the return stroke I suggest using mirror weight ONLY due to the
> apparent fact that hand pressure (placed at the edge of the TOOL by
> overhanging fingers while dragging the tool towards the body) tends to put
> undue localized pressure right at the edge of the mirror which "plows"
into
> the tool and REALLY does roll the edge.
>
> This is a REAL TDE, it's difficult to remove and is best avoided. It is
> usually a narrow rolled ring around the extreme edge of the mirror and is
> usually less than 1/8 or at worst 1/4 inch wide.
>
> Having a REAL TDE is much worse than having an apparent TDE where the edge
> receives little or no attention because with the REAL TDE, the WHOLE
SURFACE
> OF THE MIRROR must be brought down to correct the defect. An apparent TDE
can
> be a zone or more in width but can usually be easily repaired or avoided
by
> properly attending to the edge zones.
>
> To avoid confusion, maybe this should be referred to in the future as an
ATDE
> for Apparently Turned Down Edge?
>
> The "W" stroke is a modification (if you will) of the stroke I've
described
> (or maybe it's vice-versa, doesn't matter) where the center of the tool
spends
> a lot more time in the outer zones *AND* (the center of the tool) avoids
> working the central zones. Properly done, the TOT "W" stroke makes several
> strokes near the edge zone then proceeds rapidly through the center of the
> mirror while keeping the tool moving then making several strokes as before
at
> the edge zones.
>
> Properly used, the TOT "W" stroke IS BETTER than my described stroke due
to
> the combined action at the extreme LEFT AND RIGHT zones of the mirror
but... I
> find that most people (newbies in particular) do not avoid the center
properly
> when doing the "W" stroke and end up doing COC strokes instead throught
the
> center zone causing a constantly deepening center and the apparent TDE.
>
> Another possibility using the "W" stroke is a REAL TDE caused by the above
> mentioned hand position used when pulling the tool towards the body.
>
> After making a few mirrors, these natural tendencies to mis-apply strokes
> usually (hopefully) goes away with practice and proper strokes become
second
> nature but in the hands of NEWBIES working on their own, any stroke not
well
> understood can be hazardous to their mirrors figure.
>
> I hope this clarifies some of what I've been trying to put into words.
>
> Ken Hunter
>
>
>