Please critique MIG welding

[davejurek]

I've got an HTP 140 Mig welder. I've had it nearly 9 months now and I've played with it a good bit but I don't think I've nailed down the welds quite yet.

I've checked into some classes however, the only thing the tech schools offer here in Augusta is a degree/certificate based curriculum.

I've tried to emulate the nickel stack looking weld I see from Dan and RockyD but the weld always smooths over.

See the attached pictures and leave feedback. Thanks.

Dave Jurek

[davejurek]

Some scrap metal I practiced on.

http://www.knology.net/~davejurek/images/PC080006.JPG

Some recent welds I made making up a welding cart.

http://www.knology.net/~davejurek/images/PC080022.JPG
http://www.knology.net/~davejurek/images/PC080023.JPG


Dave

[Bob]

Dave,
I think it will help if you can get a little better focus. This can be a little tricky if this is a web cam or pen cam with no auto focus or view screen.
Lay a yard stick in good light and take a shot along its length with the camera at the 1" end. In the pix find the place the numbers are sharpest and use that distance for your shots.
Looks you have lots of pixels to work with. You will probably be farther back, but you can trim (crop) the shot to highlight the weld.
Bob

[Al T.]

Bob,
Thats a great idea, I'm glad you posted that. I suffer from the same problem.

[Mike Sherman]

Dave, stop everything your doing with that welder and start over. I believe you have confused Rocky and Dan's GTAW (tig) with your GMAW (mig). Get your manuel out and reset your welder to factory specs for the wire and gas you are using. A mig weld that is smooth is okay. You have several problems with your welds, but none of them are insurmountable. Start over without trying to get a stack of dimes, go slow, let the the weld wet into the sides, weaving is not necessary and then send some new pictures and we will go from there.

[Bob]

Al T.

My camera does have a "focus adjustment ring" but is not calibrated. I used the "yard stick approach" to mark a couple settings. Still not perfect, but way better as seen in my version of Dan's bending brake.

Bob

[davejurek]

Thanks for the replies so far. I've got some more pictures that I hope will be clearer.

This one is a butt weld I was stitching on some 16 gauge metal.

http://www.knology.net/~davejurek/images/PC090012.JPG

Here's an outside corner weld I tried. I basically took the gun and moved it in a steady straight line. No weaving or circular motion, just trying to fill in the gap.

http://www.knology.net/~davejurek/images/PC090013.JPG

Here's some welds on scrap metal which I was moving the gun in a circular motion.

http://www.knology.net/~davejurek/images/PC090014.JPG

This was some welds attempting the stack of dimes look. So that is only with tig then?

http://www.knology.net/~davejurek/images/PC090015.JPG

Another outside corner weld, stitching.

http://www.knology.net/~davejurek/images/PC090017.JPG

Lastly, this one is a re-shot of an inside corner weld I made. This is the most recent weld I made (this past weekend).

http://www.knology.net/~davejurek/images/PC090019.JPG


Well, check 'em out and tell me what you guys think.

Mike, thanks for your comments however, I did not change the mig settings (at least intentionally) to try to emulate the dime stack welds. I always try to dial in a setting which makes a good sound while welding. What else do you see?

Bob, thanks for the advice on the camera. I've got a digital that I was just way too close taking the pictures.

Dave Jurek

[Rocky D]

Dave I could weld with your settings, just fine. However they are a little hot for you. Your inside fillet is the best one. You have good penetration and deposition rate.

# 12 no penetration, weld sits on top, very weak.
# 14 is just plain gross, however the setting looks OK.
# 17 outside corner, too slow, overlap, lots of grinding ahead
# 15 all look like you're getting good penetration, could turn gas up a bit, need work on making beads straight, and uniform
# 19 looks the best

Over all you are getting close, work on uniformity, rhythm, and speed. Practice X 10

Don't be frustrated that your welds are'nt perfect as Dan's, but use his example as a goal, and don't get discouraged...we all had our trials and tribulations in becoming journeymen weldors....we all had someone help us out and critique our welding, too.

Keep it up, you're on the right track!

[davejurek]

Thanks Rocky for the comments. Like you said, I need practice x10!

I'm confused though. The nickel stacks are for tig welding as mentioned above, yet in Dan's brake project, he stated he used a mig welder to put it together. Is this the perfect weld to aim for or do I need a straight uniform weld such as my #19 picture above? For that weld, I moved the gun in a straight line aiming toward the center of the corner.

Dave Jurek

[dysfunction]

Dave, Get an even straight bead down before trying to do any weaves. As Mike said weaving isn't necessary and at this point its just one more thing to have to worry about. #19's definatley going the right way

[Rocky D]

Originally posted by davejurek
Thanks Rocky for the comments. Like you said, I need practice x10!

I'm confused though. The nickel stacks are for tig welding as mentioned above, yet in Dan's brake project, he stated he used a mig welder to put it together. Is this the perfect weld to aim for or do I need a straight uniform weld such as my #19 picture above? For that weld, I moved the gun in a straight line aiming toward the center of the corner.

Dave Jurek

The stack of nickels is a result of a circular motion, ans it helps to make a straight bead....for me, a steady non weaving motion is hard to do, to keep it uniform. It is also easier to keep a fillet weld straight, than just trying to do stringers on a plate.

Try to grind a nice straight groove, just deep enough to see it as you travel down the plate...it will serve as a guide, then run pass after pass and build up your plate, with nice straight passes till it's 1" thick...you will see your ability improve. After you do that, do another one.

[Dan]

Originally posted by davejurek
Thanks Rocky for the comments. Like you said, I need practice x10!

I'm confused though. The nickel stacks are for tig welding as mentioned above, yet in Dan's brake project, he stated he used a mig welder to put it together. Is this the perfect weld to aim for or do I need a straight uniform weld such as my #19 picture above? For that weld, I moved the gun in a straight line aiming toward the center of the corner.

Dave Jurek

Dave

The stack of nickels weld with a MIG is actually a slightly colder weld, then just traveling straight along the weld joint. Actually, though like Rocky D stated I too have difficult time creating a consistent weld bead in the short circuit transfer mode by just traveling straight along the joint. On 1/8" to 1/4" material I always use a slight side to side weave too. For me this does two things. For one it creates a ryhthm that helps keep me consistent. The second thing that I feel it does is improves the quality of penetration acrossed the width of the weld. By using a slight side to side motion, short circuiting is occuring across the entire width of the weld bead instead of just one focused point. As the material becomes thicker like Im discussing here traveling straight without a slight weave can potentially create cold lapping.


Now to address your weld beads.

First off, quit jumping around to so many different joint designs. Focus on one joint design at a time. Now since you are pretty close on the T joint (picture # 19) I suggest that you focus on this one first. Now as Rocky D stated, your settings seem to be a little hot on most of your welds. Try reducing your setting some and see what happens. Also try a little side to side weave. I m attaching a picture of a fillet weld ran on a horizontal t joint. Notice how the weld bead is pretty consistent along the edges. As Im running the weld bead I m watching the outside edges of the weld bead. Once it reaches the width that I want I progress forward.

Well I hope we are helping you some. Each person here is going to have there own opinion. I suggest you takre the info that we give you use it and then use from it what ever works best for you.

[Mark Whiddon]

One thing you might try is ONLY try flat welds. Ideally you should only weld in the flat position anyway (but this is not an ideal world). The reason you do this is that is much easier to control your puddle. You do not have to worry about gravity running your puddle all over the place. As others have stated, do not try the stacked nickel type stuff yet. That will come, but just put some wire through your machine. Not just a little, I am talking pounds of wire. That is the only way you will get better. Then you can try different positions, joints etc. Just my 2 cents worth. And you are right these pictures posted by Dan, Rocky and the others are definately something to shoot for.

[davejurek]

Thanks for all the comments. Your suggestions were very helpful. I turned down the heat and practiced some more welds.

First I tried some straight welds. Here is 4 beads I ran. The first, I moved the gun in a straight line. The second, I moved the gun in a circular motion. The 3rd bead is also a circular motion but a little wider. And finally, the 4th bead is in a side to side motion like a crescent moon.

http://www.knology.net/~davejurek/images/PC100002.JPG

In practicing the t-joint weld, I used the same heat as above and adjusted my feed rate based on the sound of the weld. For this one, I moved the gun in a steady straight line aiming the wire into the corner of the joing.

http://www.knology.net/~davejurek/images/PC100009.JPG

And lastly, another t-joing weld however, here I am making a circular motion as I move the gun down the joint. I impressed myself with this one! Starting to look like that nickel stack! I know I still have practice to do to get the edges to be consistent.

http://www.knology.net/~davejurek/images/PC100007.JPG

All the comments have been helpful. Please keep them coming.

Dave Jurek

[Rocky D]

I think, Dave you're are still too hot...it looks almost like spray arc. If that is 1/4" plate, the HAZ indicates either too hot, or too slow, or both