On Fri, 11 Dec 1998, econrad wrote:
> As I have followed this thread, with some interest, I'm left with two
> questions. What is a dolly? Also, is there a best way to heat to "red"
> - high flow torch, or low flow?
A dolly is a hunk of metal used while hammering.
If you just hammered on a body panel with no support, you'd stretch it and
wouldn't have any control over where the metal goes.
Dollies are usually several pounds and come in all manner of shapes and
sizes. Most common are mushroom and comma dollies (you can tell which is
which - one's shaped like a mushroom and one's shaped like a comma).
Myself I use a clevis pin (~2" dia by ~8" long) for most of my dolly work
because it's so heavy. I've also used bits of 1/2" steel plate and hunks
of bronze.
You put the dolly behind the sheet metal and bash it from the front with a
hammer. Sometimes you want to hit the supported area (on dolly), other
times you want to hit an unsupported area (off dolly). As mentioned
before, there's also shrinking dollies for use to - gasp! - shrink metal!
For a better introduction to hammering metal (tin-bashing), get thee to a
library and find a book on sheet metal forming. Look in the glossary
first so you don't get lost in jargon :-) There are also a few good
web-sites out there in the ether that can help a lot.
Heating:
For my work I use the oxy-acetylene torch with a small (#0 or #000) size
tip. You could probably use a propane-ox or propane-air torch BUT they're
not as concentrated as a oxy-acet flame, and thus wouldn't give you the
fine control of the hot hot flame.
I don't know what you mean by high-flow vs. low flow torch...? By my
guess the Victor welding torch is a low flow, and the Tiger (3" bore)
"rocket engine" torch is a high-flow?
-Malcolm
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