I just to my Lincoln Squarewave last night..yippee, and mastered mild steel in an hour or so(dont even ask how many times I stuck the electrode to the workpiece ).
I tried aluminum this morning and it worked OK...but the welder seems to be straining VERY hard to weld 1/16 inch thick aluminum. Sometimes it welds, and then sometimes it just curls up and blobs whatever workpiece Im trying to weld.
I have a radiused tip(the copper thing), so I know thats not the problem. Contamination maybe? Id post pics of all of my welds so far, but the damn camera ran out of batteries....

 

how much amperage does your welder have? are you trying to weld it ac or dc?

 

oh...175. Ive been trying with AC....

 

heres some pics of the 1 bead that I did lay down....


ugly i know, but with time and practice(and a little help ) I think the welds will come...

 

those are my boxes in the background!!!! hehe

 

FWIW, preparation is extremely important.

just keep at it.

 

Tinker,

Thats not bad for starters! OK, the noise level on aluminum will be about 5 X that of mild steel. I assume your running DC- on steel, that's nice and quiet. AC on aluminum! That makes a howl. Don't worry about overloading the lincoln's. There designed to meet nameplate ratings.

Now on aluminum its preparation, preparation and more preparation. You want a nice rounded tungsten. I usually get that by going DC+ and using a copper block on the ground side and hitting the pedal hard to make that nice round little glob on the end.

I usually abrade the aluminum where it is to be welded to get the thicker layer of aluminum oxide out of the way. Then wipe the surfaces down with acetone where I am going to weld. Even then we often have a hard time of it.

Hope this helps some. Good luck. I got the big brother of your lincoln the squarewave 275 and love it! Have fun.

Regards,
BigMoose

 

Also aluminum doesn't look the same when its melted and in a puddle. looks to me that your way over heating the material. Try moving faster and it might work for you. I had a hard time at first also. I just started and I found my 1/16" tungsten is too small.. I'm going to get some thicker ones soon.

 

I tried al. with my mig that's supposed to be able to do it, but it sucks and doesn't work. I read though that you should use 100% argon and clean the surfaces well with a stainless brush.

I'm sure when tony1 gets here he can give you all the advice you need!

 

thanx moose...the only thing that I havent done is the acetone...i will try that...rubbing alcohol????

 

i pm'd you about the oil feed/return.

mike

 

Where did you get your welder from?

 

local shop..michigan Airgas...it was $16XX? with 125 c.f. tank, 2 lbs of filler material and an auto-tinting mask. My dad put it on his CC to write off for his business
$1,600 something though.

 

when welding aluminum I like to be agressive on the foot control initially to get the puddle started as fast as possible. when the puddle forms, i back off the foot control some and find the right spot to get the weld flowing. you got to weld fast when doing aluminum, and you can't keep the filler rod too close to the torch like you can with steel otherwise it will melt before you are able to dip into the puddle. the lincoln squarewave is a good machine. in comparison to the more expensive miller dynasty series i've used, it was a lot easier to lay down beads for a beginner like me.

also try using 0% thoriated tungsten when welding aluminum, i hear that helps.


[Modified by SEFI8LOxCivic, 10:19 PM 2/27/2003]

 

The acetone is to get ALL the oil off and out of the way. You want something volatile like acetone or lacquer thinner. Rubbing alcohol isn't the best at getting oil out of the way.

Abrading the aluminum oxide layer is more important though. All the other guys had good suggestions too.

Regards,
BigMoose

 

they also say that using helium or a helium/argon mix makes aluminum easier because it requires less amperage to get the weld flowing.

with enough practice you shouldn't need any particular gas or tungsten. 2% tungsten and regular argon isn't that hard to run some nice beads.

 

I found the problem...I was trying to weld cast aluminum. I went from that, to a quality piece of aluminum and it was like night and day...it actually welded
I spent most of the day laying down some decent beads, so tomorrow I will start making my water to air intercooler.
I was just going to weld onto the existing cast end-tanks of the IC that Im using, but I cant form a puddle for nothing. Off with the cast tanks, and on with something I can weld
Of course pics will be posted asap
Oh ya, I completed my first application today...welding a wastegate elbow onto a manifold...I like it. The only problem is that the TIG weld puts the rest of the manifold's ARC welds to shame

 

Thanks for showing me the "drag the puddle technique". That really made a difference on my welds man!