On Mon, 14 Jul 2014 17:59:33 +0100, "harryagain"
wrote:



I have only seen very thin aluminium welded by laser but is was an automated
job, not by hand.
I have been told it can be done by resistance welding.
Doing it by hand would be some trick.


I expect someone else has already mentioned this (but I can't be arsed
to read the entire thread). You can weld aluminium foil by friction.
Two layers of foil are layed on top of one another. You then create
the welded seam by spinning up a nylon disk to several thousand RPM
and skim the foil surface with it.
Now if someone could weld tin foil with an arc welder, that really
would be a most remarkable feat!