Welding Tips and Tricks

Would an aluminum expert please educate me on why when I use my 3/32 tungsten my torch runs a nice shiny bead. However if I change to a 5/32 tungsten I get dark digging gashes. All torch parts are brand new with both tungsten. Tungsten are new. Amps do not make a difference. The more silvery looking lines at the top right of the photo are with the argon turned up above 30-40 cfm with the 5/32 tungsten but still had black particles. I was using gas lenses 7 ,8 and 10. The three shiny lines are from the 3/32 tungsten (upper left and bottom right). I don't have 1/8 tungsten so I couldn't try those. The only thing to correct it was to reduce the size of the tungsten. I ended up running my 3/32 at 225-230 amps and it worked. And that was with only 12-15 cfm. I tried running the 5/32 at 12 cfm up to 40 cfm. Just don't get it. Does the 5/32 just require a butt load of argon even though the 3/32 can do it with 12 -15 cfm? 1/4 inch aluminum plate.

you're probably crushing the collet and making it butt up inside the collet body. there has to be clearance for the gas to escape through the gas ports. Are you using 5/32" specific collets and collet bodies? Or are you throwing parts together that are meant for other size tungstens??

Blaze,
It would be pretty hard to confuse 5/32 parts for anything else but sometimes collets and pilots don't mix, we had a post quite a while ago where somebody ran into this. Seems that some collets are different lengths. That was causing a flow restriction. If you have a ball float type flow meter and it reads up to 40cfh then I would say you don't have a restriction. On the other hand, if it's a gauge type you can get a false reading. Do you have verified flow at the torch?

Only other thing I can think of would be bad tungsten spitting out into the weld, it happens. Is this pure tungsten or a blend?

Len

I'm using a gas lens and I checked to make sure the collet inside is the right size. The slots in the collet are there to let the collet squeeze down and hold the tungsten correct? The gas comes into the torch, flows around the collet and out the gas lens it seems. What would moisture in the gas do? Ball float gauge.

Blaze,
Moisture in the gas adds the 2 things that you're most trying to keep out of the weld, Hydrogen and Oxygen.

If you have a restriction in the gas flow and you're using a floating ball type flow meter it will not float for long at the set level before it drops off to the actual flow rate.

There's a fairly simple test to rule out gas issues. Switch your machine to DCEN and clean a piece of steel shiny bright and light up on it and form a puddle. Let the arc drop and hold the torch still for about 10 seconds or so through the post flow without moving the torch. If the puddle and the tungsten both stay shiny , then you don't have a gas issue.

Gas issues can also be causes by leaks in the Argon circuit anywhere from the regulator to the torch. A low pressure leak can siphon atmosphere into the system and contaminate the gas. Another thing that can cause issues is too much flow which causes a vortex and draws atmosphere in right at the torch.

Have you changed out cylinders lately? Is the gas pure Argon or a chance it could be a mix? Have you welded with this same exact setup before this without issues? If you changed anything lately, change it back and see if the problem goes away. This includes the filler rod and where it's stored, how you clean the parts, any variable. You're going to need to become a detective here to narrow down the cause.

Len

Len,
I have changed cylinders. I'm going to try your puddle tests Wednesday. I'll check for leaks first even in my torch line. Thank you for your time!

Blaze,
You need to be suspect of bad gas any time you change cylinders and you start having problems after. I've explained in prior posts how this happens and it's likely you got a mislabeled or contaminated cylinder of gas. Return it your supplier and tell them that you believe you got bad gas. I've not heard of any suppliers refusing to exchange cylinders if you're having issues.

Len