DIYbanter - View Single Post

Don Foreman

On 27 Jun 2008 06:37:15 GMT, (Curt Welch) wrote:

Ned Simmons wrote:
On 26 Jun 2008 04:31:25 GMT, (Curt Welch) wrote:

Aluminum conducts heat away from the weld faster than steel so it takes
more heat to weld aluminum than steel for the same size material. As
such, the small mig machines (which can't weld very thick steel to begin
with), have any more trouble trying to weld thicker aluminum.

I much prefer TIG for aluminum and my personal plan is to get a machine
like the Miller Dynasty 200 for steel and aluminum (TIG and Stick).

The high heat conductivity of aluminum will also limit that machine to
relatively light material. Welding 3/16 aluminum will be pushing the
welder quite hard. You could probably do 1/4 in a pinch with preheat,
or on small pieces.

Yeah, most my interest is in small robotics projects which should be
limited to about 1/8" so I think it will do ok. If I find it's not cutting
it, I'll just have an excuse to buy more hardware! Thanks for the heads
up.

I think you would find a small TIG much more to your liking. MIG can
do ally, but thin ally is tricky and thicker ally is beyond the
capacity of a small MIG box. Thin ally is tricky because you need to
have everything set up just right -- and then maintain a rather brisk
welding speed. MIG

TIG affords much better control. You can weld at whatever rate is
comfortable, a definite advantage on small projects. You can change
from ally to steel and back without changing anything other than AC to
DC and perhaps changing the tungsten. If the joint design permits,
you can do autogenous welds in which parent metal is fused together
without addition of filler. With MIG, you are *always* adding filler.
You can't go back and remelt without adding even more filler.

TIG can do about anything MIG can do, though usually considerably
more slowly. On small jobs where a modicum of precision might be
sought, that can be a distinct advantage.