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Old 01-22-2009, 10:41 PM
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mccutter mccutter is offline
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Join Date: Mar 2006
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Default Some like it hot...

I'm sure many of us here will tell you that you are potentially spinning your wheels trying to weld aluminum with a MIG gun, teflon liner and "weak" machine. Aluminum needs a lot of heat (amps). And I (we) speak from experience--been there, didn't do that because it didn't work all that well.

The scenario is that in order for the wire to feed and not birdcage you need a stiffer wire (5356). Right off the bat, 5356 needs about 15% more amps than 4043 to weld properly, hence, your machine is "turned up all the way". You may never get enough heat into the work to get good penetration, especially 3/16". You might do OK on thinner gauge. I don't think the liner will help you that much with 4043--the MIG gun has to remain nearly straight, especially with a thinner wire.

This is not to say that it can't be done--maybe try some pre-heating of your work with a propane torch? I can't help you with your settings.

A good rule of thumb is to not breathe ANYTHING coming off of the weld. Hold your breath or use a respirator. I can't explain the white smoke...maybe normal?

Normal MIG welding is done with the "short" method (vs spray). The filler wire contacts the work piece, shorts out, heats up like a lightbulb, then melts into the puddle. This is continued over and over again while the trigger is squeezed.

With spray arc, the filler wire melts BEFORE it reaches the workpiece and is deposited in smaller drops but at a higher rate. This process requires much more power and is used on the larger, higher-end machines.

Read the attached pdf courtesy of Miller--it is a little more descriptive of the various processes.
Attached Files
File Type: pdf migarcs.pdf (173.2 KB, 764 views)
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