hey guys...

been welding some aluminum and i am having a problem.... i can weld the plate or tube very easily... but when i try to do a peice that i cut and clean... it just spatters. (see below) it looks dirty, but i assure you it was clean when i was done prepping it



i am using a stainless brush that is dedicated to aluminum to clean the surface and the joint prior to welding and an acetone wipe after that. you can see that i am welding fine up to the joint... and at the joint all hell breaks loose. cut with my band saw.

suggestions?

100% argon, 1/16" tungsten on AC (tried 2% and pure... same result) with 1/16" 5356 and 4043 rod... all the same result. AC balance is set to auto on my precision 185 with no pulse.

Matt

 

Two of those 3 beads don't show any cleaning action. Is that because you cleaned it off? (I know you're asking about the other joint, but I'm curious if you're getting a full ac wave).

When welding aluminum, it's important that your joints be very tight, or else the arc will jump between the two parts and will heat them unevenly. And with a tiny lip like you have there, it won't take much to heat soak it and just blow right through it. When I tack pieces like that, I will hold the part down against the table real hard and heat the tack over again to make sure it's nice and tight.

Once you have it tacked properly, try and see if you can just make a small puddle without worrying about the filler. Set the machine to max cleaning (for the purpose of this test) and see if the puddle will come out clean. Watch all the garbage come up. If you can't get a clean puddle and it's just twisting and turning, then you definitely have time type of external contamination. Try cleaning the joint (inside and out) with acetone. Make sure there isn't a layer of anodizing or clearcoat etc ...

Try the puddle idea, and report back!

Hope that helps!

 

Thanks Markku!

I am headed to the shop tonight...
I had the AC balance set to auto... so i will play with it some.

Also, the reason the 2 of three beads dont look clean is because i did those two, then welded the seam and then cleaned the whole peice off and ran another bead to make sure nothing changed.

 

Markku, I just did what you mentioned and ran a marvelous bead.

I was so excited I almost called you, but I decided not to bother you while your working.


Here is the fitup all clean, the tack and then the weld with full clean.




(edit: I know I need to work on my steadiness when welding pipe... Work in progress)

May I inquire as to why the ac balance to full clean would help so much?
I know it was dirty before, but the auto setting should be able to handle that?

Matt

 

Glad it worked out. I don't need to mention the steadiness, that takes time, but you can see it's nice and clean. Good stuff!

Two reasons I suggested max cleaning. 1) The majority of the heat is directed towards the tungsten, which gives you more "resolution" in the pedal control. 2) Max cleaning usually breaks up the surface nicely and tends to pull out all the crap that might be in there.

Just be aware that sometimes too much cleaning can work against you by pulling up garbage from the underside and mixing it into your puddle.

Glad it worked out!

 

Still working on my Al welds. Consistancy is getting better with time too!

I have since this post started to prep the two surfaces that have been cut with the bandsaw with a 3m disc just to grind the surfaces from potential contaminates.

I think that it is doing the job.

 

looking better, takes practice and more practice. good luck, one day it will be like a light switch going off, "ohhh that how you do it, and thats what i have to do".

if something isn't working for you, slightly switch it up. Such as angles of torches and filler, speed of dipping and torch advancement, everyone does it a little different. Keep an open mind and don't be afraid of trying new techniques.

Fitment and Cleanliness is key