On 11 Oct 2005 04:35:15 -0700, "mhorowit" wrote:

"feathered cone?" No, I'm using a neutral flame, the two inner cones
coincide and there is only the faintest hissing noise. More Ox and I'd
have an oxidizing flame. - Mike

Mike, the way I've been welding and the way it's taught in the EAA
video is that you need to have a slight feathered edge to the inner
cone. The reason for this is, you cannot tell whether you have a
carborizing flame or oxidizing flame if the cone is neutral without
that feathered edge. It is a visual indicator of how the flame is
set.

My experience after welding the complete tube fuselage for the
Christavia Mk4, and other projects, is that the torch can and will
change setting now and then, or at least mine did. If you have set
the cone with a slight feathered edge, you can tell when the torch
changes it's setting and re-adjust immediately.

Also, the description you made sounds an awful lot like you had too
much heat. Any time you are burning holes in your work, you need to
either reduce the flame, move the flame further away or move quicker.
You might even have to reduce the size of your torch tip. Oh yes,
there's one more way to reduce burning through, use the filler rod as
a quencher. Adding the rod reduces the temperature of the puddle. If
you are using a very narrow rod, you might be able to move up one size
rod and keep the flame the same size. But this means dabbing the rod
in the puddle constantly, or you'll burn through again.

Corky Scott