Please Critique My Welds(4th day Welding)

[JustinOlson]

I've been tig welding for 4 days now and would like people to give me pointers and a general critique of my welds. This is on a lincoln 275 I think. I really want to try a miller.

 

Anyway, some of these are stainless and some aren't. I'm not fast enough on stainless as the welds are rather dark and too big for the thickness of the material(16

gauge).

 

How are you guys moving the torch? Is there a pattern that you move the torch in to smoothly move the puddle along and make a nice weld?

 

MILD 12 gauge:

 

 

 

Stainless 16 gauge:

 

 

 

 

 

Modified by Justin Olson at 12:14 PM 7/30/2006

[daveshybridz]

those look good , can you show some of the backs of them so we can see the penetration?

[ZuL8r]

First let me say good job. It looks like you are learning quickly. I may be looking at them wrong but it seems that your weld is below the face of the material on some of the first pictures. This introduces a stress riser to the material. It is best if the weld is even with the material but its ok if it is higher. I could tell you more with some horizontal pics.

[cheftrd]

First, you are doing well for four days of practice. That said, here's a few observations:

 

Your weld speed looks slow. That's why the bead appears bunched up and the heat affect zone looks wide.

 

On some of the stainless welds, the weld deposit looks contaminated. It's very important to ensure the welding rod does not leave the shielding gas envelope between "dips".

 

The first weld appears to have a substantial curf. The heat affect zones are not even on both sides of the weld. When welding beads on a solid plate or doing a but weld on identical thickness pieces, try to have the torch standing up at 90 degrees from the plate. The only angle should be back, so the arc is pushing the weld puddle forward. You have it angled over to one side a little. This is pushing the deposit to one side and leaving the curf.

 

I puddle the metal and then pull the arc back to the trailing edge of the puddle. Then dip the filler rod and move the torch forward. Once the puddle "catches up", I pull the arc to the back of the puddle and dip again. So on and so on. push-pull-dip, push -pull-dip... This is very quick action and takes practice. High speed material like aluminum and magnesium (10 to 12 inches per minute) won't allow you to pull the arc to the rear of the puddle before dipping. It's just stop and dip, stop and dip...

 

You can download the entire tig welding handbook from Miller welding

http://www.millerwelds.com/education/TIGhandbook/

[Pop N Wood]

My advice is to concentrate on making effective welds and not pretty welds. To evaluate that you need to cut a cross section of the weld and check for even penetration with no undercutting of the base material.

 

Making the weld look like a stack of quarters will come with time and practice.

[AK-Z]

3rd pic: need a little less heat and a slower pace. I agree with what Pop N Wood said. You should post the under side also. I would rather have a weld that looks like crap but fully penatrated (too much filler rod) over one that looks pretty but not penatrated completely.

[SHO-Z]

One sugestion, Learn how to walk the cup! You set the ceramic cup on the piece to be welded, rock it forward to start the arc, then rotate the torch handle back an forth advancing the torch on the metal.

 

It takes some time and practice to learn this process by your weld will look really smooth. Practice with the welder off and get the rythum of how it is done. I was a tig welder on pipe and this is how the pros do it.

[Jolane]

Not to completely disagree with SHO-Z, but I think walking the cup is very common in the pipe field, but not usually recommended for general TIG welding. I only say this because I have read about both methods, and heard the debate back and forth about which is better and why. My impression was that walking the cup was really a trick used when pipes line up perfectly, and it can really help for out of position welds in this situation. It should also result in a very consistent weld. For corner joints and the such though, I have not seen it recommended.

 

I agree with everyone else, your welds are looking pretty good for the amount of time you have been welding. The only major problem I see is undercut. As someone else mentioned, undercut is bad. This can be caused by not enough filler, too hot, too slow, washing the toes with the torch, etc. I would recommend cutting across the weld and look at the penetration.

 

Keep practicing and you will be making great welds in no time!

Joshua

[JustinOlson]

Latest and Greatest Day 6:

 

 

Stainless:

 

 

 

 

 

 

Mild:

[AK-Z]

3rd pic: need a little less heat and a slower pace. I agree with what Pop N Wood said. You should post the under side also. I would rather have a weld that looks like crap but fully penatrated (too much filler rod) over one that looks pretty but not penatrated completely.

Oh, for some reason I thought was mig welding. faster pace, less heat.

 

Running a second pass is fine IMO.

[AK-Z]

Much better. try butt jointing. you want to set the plates so the one end is wider than the other to comp for thermal expansion. one end should be a filler rod width apart and the onther end, 2 filler rod part (foot long piece). Then start at the narrower end.

[OlderThanMe]

Pretty good. My welding instructor always try to keep the torch moving consistantly. I would use a Zig-Zag pattern for almost EVERY weld. MIG, TIG, or stick. I'll put up a pic of an overhead 1/4"steel "T" joint TIG weld I did... It was 6" long and took about 4 minutes. Near perfection.

I try to make the bumps as small as possible and doing a zig-zag reduces the size of the bumps.

[cheftrd]

Much better. When you're running a bead on a flat plate (no but joint), try not to burn through (pic #3?). The discolor is fine but the actual burn through will fail you on an AWS cert.

[OlderThanMe]

Justin, What travel pattern are you using?

[JustinOlson]

I move forward, stop, dip, forward, stop, dip. I dont really come to a complete stop tho, just slow down as I'm diping. I dont move in a zig zag unless it is a t joint or large bevel that I'm trying to get good penetration. If its a nice lap joint or butt joint I move straight along the seem, and make the puddle as big as I want with the amount of pedal and filler.

 

Funny, my latest welds are getting much better. No sugaring (burn through) on the back side and pretty consistent bead size and color. I was talking to my welding instructor and he told me he can get me a job tigging stainless at $18 an hour at my current ability level. Pretty crazy to me since I've only been doing this 3 weeks. I'm just going to keep practicing and get better.

 

Regards,

Justin

[OlderThanMe]

yeah...but most places want two years of exp. as well.

I was told that as well but none will hire at that rate with under two years of experience in that form of welding.

Try tigging on aluminium... it is a whole different game.

When I do my zig-zag with tig I do it very rapidly. I feel that I can control bead width better that way. You can use lower amperage as well.

[JustinOlson]

 

 

 

 

 

 

 

 

 

 

[johnc]

My impression was that walking the cup was really a trick used when pipes line up perfectly, and it can really help for out of position welds in this situation.

 

Like when welding behind a tube using a mirror to see the bead and where to dip the filler?

[cheftrd]

Like when welding behind a tube using a mirror to see the bead and where to dip the filler?

 

Exactly. And you must be able to do this for a cryo or "N" (for nuclear) cert. PITA.

[cheftrd]

Justin, now try some but welds using backing gas or tape. The back side should end up looking like a weld, as well.