[TheForge] for andy gladish re: aluminum

[Roger Olsen]

Hi Andy,

awhile back you asked about forging and annealing aluminum.  This just came thru
on the 'artmetal' list.  I thought you may find it of interest.

R. Olsen
_____________________

I think you covered it very well Richard.
The only thing I could add is that a "wooden paint stick" like the ones
you get when you buy your paint. Are a great tool to tell you the temp
of the aluminum. I've got them laying all over my shop with the "High
Tech Temp Stik" label on them. You rub it on the aluminum as you heat
it. When the aluminum is cold the stick feels like an eraser on it, but
as it heats up the feel starts to get slippery. And the visual gauge
is.. As the aluminum gets up to temperature the stick will begin to
leave a mark. At the lower temp. it's a little colored mark, but as the
temp. comes up, the mark left gets darker. You'd never want to get
above black or you'll get that melting feeling. It takes some practice
but you can get very predictable results in a hurry.
bill
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On Saturday, July 2, 2005, at 05:47  PM, Richard Ferguson wrote:

> The way that I was taught to anneal aluminum was to use an
> oxy-acetylene torch.  You start with pure acetylene, a low sooty
> flame.  You then cover the piece with black soot.  After that, adjust
> the torch normally, with oxygen and acetylene.  Use the torch to burn
> off the soot.  When the soot is gone, it is annealed.  (This would
> apply to sheet, not necessarily to thick pieces)
>
> My track record on this is not too good, in that I sometimes overheat
> the aluminum, usually when trying to burn off the last of the soot. It
> is pretty obvious when it happens. I suggest stopping after most of it
> is done, letting it cool, and then going back to the spots that still
> have soot.  The heat seems to be additive, and when the whole piece is
> hot, it is easier to overheat one area.
>
> I know that other people have other techniques.
>
> Richard