Aluminum Welding Question

[Sroufe7]

Sorry but I never said I was ready. That is why I posted on here to get tips and pointers.

I will not attempt to weld the manifold until I am very comfortable.

I do clean the metal with an aluminum only stainless brush. I have never wiped the metal down with anything or the filler rod.

I have heard about preheating the metal in an oven, but I was told with this thin of an object, I shouldn't have to worry about preheating.

When I am welding is when I was having problems with the tungsten getting so hot. I think it was because it is to small for the amps I was using at the time.

Again, thank you for the pointers. I will post more pictures up later.
Scott

[TJS]

Keep practicing. Yes clean is the key. Also when you wipe your filler with acetone you will be amazed at the black at the cloth you used to wipe. Might want to get some scrap round stock alum. or old alum fittings and clean them up and try welding them on some flat stock the same thickness of material. The rule of thumb for amp settings is for ever .001 (one thou) you need 1 amp. Thus 1/8" is .125 so a starting point will be 125 amps. I use about 135 to 140 for 1/8" and control the heat with the pedal. You might want to search on grinding tungsten, argon flow settings, and cup sizes.
T.J.
www.tjsperformance.com

[Craig in Denver]

You have a good puddle, so I think the 120 amps is OK.

Your 1/16th is too small for that alum. The 3/32 will be right.
Include a picture of your tungsten, if it's not a flat gray color. Some guys can tell something from that. (if it's blue, turn up the post flow)

I let my square wave do most of my cleaning, that works well enough. BUT, you have porosity or impurities in all of your samples; something is wrong. Maybe you can turn the balance up, favoring the cleaning half of the cycle. I don't know if your welder will do that. The gray path along the sides of your welds is very narrow, showing low cleaning.

TJS said something about lifting the impurities out of the casting. As a hobby welder I've never been exposed to cast; but this could be VERY important. I did read something in a boating magazine that said your puddle should be wider into the casting; that will give a good mixture of your 4043 into the casting.

PS Your tungsten must NOT have a little bulge, just above the ground tip. This is caused by dipping your tip while welding. This would cause the porosity. Break off the bulge and regrind. When I do this, my arc turns green.

[mooseye]

Not knowing your background, I am going to take a guess that you are running this like you would steel or stainless steel. That is, you are welding over the wire. I find this very difficult on aluminum.
The technique I use is to get the puddle going as someone suggested and then dab your filler in. Move the arc away from the wire feed side and you will see what looks like a small keyhole. Keep this keyhole molten and dab your filler into it under the arc to form another puddle. Then continue this process all the way around or across the area to be welded. As has been stated, this happens at a fast pace and you must keep moving or you may see your manifold develop a large hole where you want a weld bead.
I find this method makes it much easier to control the bead size and shape.
I hope you do have a foot or finger amp control as aluminum requires less and less amps as the weld progresses.
You are correct in thinking that you need at least 3/32 tungsten for 120 amps. The gray you have ordered is able to take more amperage so you might be able to use a smaller size for greater control.
And as others have said, practice..........! and Clean!

[HMW]

I've welded lots of cast aluminum and it always has impurities in it. You'll see it burn out. Like TJ, I often heat it some, then brush off again with stainless brush. Of course there are a ton of different cast and some have more crap in them then others, good luck keep practicing.

If your using a transformer machine you should have a nice little ball at the end of the tungston. I believe an invertor machine will keep the point, at least it did when I demo'd one

[TJS]

Might want to check this persons site out. He does nice work.

http://www.hotrodsolutions.net/

T.J.