help with MIG welding aluminum

[TEAMKLR2BAR]

I have read all the info on doing this, and I am welding thick flanges. Actually now I am just practicing. Does anyone have any tips? I have been successfull with the lower power settings but as soon as I try and crank up the power it just immediatley melts the entire length of alu filler wire that is sticking out of the gun. I have tried to ramp up the feed speed but doesn't seem to help. Does that mean that I need thicker wire to go up in current?

Firepower 120 mig
no spool gun
straight argon
am preheating before welding

I will be purchasing larger tips and a teflon liner for my gun and cable tomorrow. Does anyone else have any suggestion of what I should purchase in addition to that? "besides a tig for my house? haha"

I want to know so I don't have to drive to the shop "have a syncrowave and a dynasty dx there" everytime I have something alu to weld at the house.

[hankj]

I'm afraid that the problem is your welder's size. The FP 120 ia a 110V machine with 110 amp max ouptut. If you say you are working on "thicker" material, I don't think you have the power.

Hank

[TEAMKLR2BAR]

thank you for your info, what I mean by that is that I am not trying to welding intercooler tubing or thin stuff. I am practicing on 1/8" plate aluminum. It welds a very nice bead on the lowest setting but as soon as I try it on any of the higher settings "there are 4 power settings" it just burns through the wire.

[Andy249]

This welder would be right on the edge when trying to weld 3mm Ally. I think my old mig with analogue gauges used to give me a reading of about 170 - 200amps or thereabouts as a general rule for this setup. If you think your welder is generating enough heat, you may have to increase your wire thickness, I use 1.2mm, as your rollers will probably not be feeding fast enough. I agree with Hank though, this machine is not really big enough for welding even 3mm Aluminium (or at least properly).

[TEAMKLR2BAR]

I don't nessecairly think that I do have enough power. Just seems that logical that if it works great on the #1 setting and it burns through the wire on #2 or above that I do have enough power, at least for what I am doing right there. I have messed with the feed speed also but to no avail. Do you think that that is a fair assumption that I should just switch to a thicker filler wire and go from there? Remember, this is really playing around. If I have something important to weld that is alu then I will just do it at the shop where the tigs are.

[timw]

Sounds like wire feed problems. What you are discribing is wire burn back. Alum melts faster and different than steel and wire speed needs to be cranked up. Your machine might not be feeding fast enough or slipping on the rollers. With Alum it's a fine line between a good weld and a puddle of metal. You didn't mention it as a problem but for anyone else looking here for more info on Alum remember it can't be too clean and use a stainless steel brush because a steel brush will ad contamination.

[DDA52]

I've been playing with alu and my MM135 as well. I've found out that the 4043 works the best for underpowered machines. I agree with timw also. If you have burnback, crank it up (ws) if the drive isn't slipping. Alu needs all the heat it can get because of its high dissapation rate. The small MIGs just don't have enough oomph. They will still work for playing around and non critical stuff.

Here is my setup. 4043 at .030 with a .035 tip and straight Argon. The settings I got the best results from were at the upper end of the range for the machine. Keep the gun cable as straight as possible. Everytime I let the wire stub the work, I got a birdnest. I was probably getting 1 birdnest for every 3 inches of bead. Here are some pics. Everything was on 1/8 alu. The last pic is of the beginnings of an apartment complex for our feathered friends!

[fun4now]

about 520ipm

thats shootin out some wire,
TEAMKLR2BAR
you should check your welders wire speed you may not be able to reach 500IPM, check and see what speeds you can reach, i have had wire burn off almost like globular tranfer cuz it wasent going fast enough . that could be the culpret here.if you can reach thouse speeds check to see that your wheels are not slipping more than pushing. might try loosening the wire role holder to alow it to spin easyer so the wheels can push out the wire easyer.
good luck
DDA52
nice work