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 :D

[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

[Dan]

Dave

What material thickness are you welding on? What wire size are you running. Any idea on how many IPM on the wire speed? What about your voltage?

Like Rocky D stated it still looks like your running to HOT on the settings. Looks to me like your welding on sheetmetal. Just guessing though. If so, you should only be traveling straight- no oscillations.

I can see that you are not going to give up on this stacked nickel technique :) . Ok, first thing you should know is that I only use this technique on 3/16" and 1/4" material. And then only on fillet welds and horizontal buttt joints. I recommend that you only use this technique on non- life threating structures. Something like the bending brake project is an acceptable time to use it-slight hint :D :D :D . Anyway, with an .035 solid wire somewhere between 240 and 260 IPM on the wire speed works quite well. If your using 75/25 shielding gas you want your load voltage to around 18 to 19 volts. And with 100 % CO 2 around 20 to 21 volts. The oscillation technique actually isn t a circle, but an elliptical motion instead. Now Im posting you one more of those annoying example pictures. I know that I have posted a similar picture in the past, but I wanted to post another one to refresh your memory on the oscillation technique. As in the previous picture I scribbled the oscillation next to the weld for you. Thank goodness I can run the weld bead better then I can draw it:D . Don t forget that red dots stand for a pause. The pause is very definate. The oscillation to the pause is actually fairly quick.

You know, I m sitting here wondering if there is anyway that I could actually mail you a sample weld and it make it to you. Maybe if I took it to the post office and had them put it in a package and mark it some how. Don t know just a thought.

[davejurek]

Rocky/Dan,

Thanks for the responses. I'm welding on 1/8" plate (16 gauge?). I'm using an HTP 140 which is a 110V machine. Heat setting is at 2, no load voltage is 25.3 according to the manual at that setting.

I'm welding with .023 wire and the wire feed rate is set at 2. I don't know how fast that is without measuring it but if I increase it, I get popping and lowering it seems to melt the wire too quickly. The shielding gas is the standard 75/25 mix.

As far as the HAZ, its going to be wider on thinner material, right? I did try turning down the machine to setting 1 but the weld appeared to sit on top of the metal.

What is spray arc?

Dan, I'd love to receive some of you welding coupons. Your welding is awesome and definately something to reach for. Yep, I like the nickel stacks! :D


Dave Jurek

[grocery_getter]

Dave, I think your enemy is the gas that you're using. The 75/25 gas is a hard gas to learn on. To get a good penetration on 75/25 gas you have to turn the setting hotter than on a pure CO2 gas.

Turning the setting hotter in itself is not a problem if you know what you're doing but for learning how to weld, its better to use pure CO2. The weld will have better penetration with a lower setting, you can go slower and not have the piled up weld bead look, get better penetration thru the material you're welding on and have a chance to slow down and learn your technique.

Now the reason I know this is because many years ago I also learn how to weld on the 75/25 gas. I ended up a very frustrated newbie welder because no matter what I do, even with a good weld bead apperance, its very hard to achieve a flat bead. The bead just stick up on top of the material. I switched to pure CO2 a couple years back and have never looked back. The C02 just pure flatten the weld bead down -> better penetration.

When you're just learning, use CO2, after you've perfected your technique, you can try the 75/25 again if you'd like. Your gas dealer shouldnt charge you much at all to bring in the 75/25 gas tank and exchange it for the pure CO2. Pure C02 is dirt cheap compared to 75/25, hence the financial reason why most gas dealer try to push 75/25 on their customers (especially the newbies) even though they're probably not ready for the 75/25 characteristic.

Andre

[Dan]

Originally posted by davejurek
Rocky/Dan,

Thanks for the responses. I'm welding on 1/8" plate (16 gauge?). I'm using an HTP 140 which is a 110V machine. Heat setting is at 2, no load voltage is 25.3 according to the manual at that setting.

I'm welding with .023 wire and the wire feed rate is set at 2. I don't know how fast that is without measuring it but if I increase it, I get popping and lowering it seems to melt the wire too quickly. The shielding gas is the standard 75/25 mix.

As far as the HAZ, its going to be wider on thinner material, right? I did try turning down the machine to setting 1 but the weld appeared to sit on top of the metal.

What is spray arc?

Dan, I'd love to receive some of you welding coupons. Your welding is awesome and definately something to reach for. Yep, I like the nickel stacks! :D


Dave Jurek

Dave,

1/8 material (.125) is roughly 11 ga. (.1196), and 16 ga. (.0598) is roughly a 1/16" (.0625).

Now if you are welding 1/8" material alot of your headache is being created by the diameter of wire that your using. An .023 wire isn t going to produce short circuit transfer on 1/8" material. The current needed for welding 1/8" material is going to put an .023 wire into the area were it wants to go into a spray transfer mode, but since you are using c25 shielding gas you are going to end up with a globular transfer. This explains why the pictures of your weld beads looked hot.

Now what I suggest is that you replace the .023 wire with an .035 wire. Or at least get rid of the .023 and use an .030 this diameter would still allow you to weld thinner material and shouldn t transition over to spray transfer (globular in your case) on 1/8" material. Keep in mind though that with .035 wire on your machine you should be able to weld 16 ga with no trouble and NON structural projects with the stacked nickels oscillation on 3/16" and 1/4" material.

Well this is all I have time for now, I need to go to work. Rocky will probably be on here in about another hour or two. Maybe he ll add some more. Follow thru on changing your wire size and it should help you.

[Rocky D]

Dave, I understand now what is happening, here. Dan hit the nail on the head...try .035" wire, but for now stick with C25 gas. I'm afraid changing to CO2 right now will confuse you, big time.

Do a search on here on "spray arc" (use quotes) and you will find some of my stuff I'm real proud of, and more that you ever wanted to know about spray transfer welding.

Practice, practice, and more practice, and don't get discouraged! you can do it.

[Mike Sherman]

Sorry Dan, I'm gonna have to disagree with you on the weave vs stringer bead concerning short circuit mig. There is significant research to suggest stringer beads in general are stronger than weaving. Cold lapping is nearly synonomous with short circuit mig regardless of the technique (ever wonder why D1.1 doesn't prequalify short arc??) and weaving will put more heat into a plate than a stringer will regardless of the process or technique. There really isn't anything wrong with a slight weave when using a mig, there just is no real reason from a technical point of view to do it. Have fun guys.

[Bobby]

so as a hobby-welder trying to understand this all:

with GMAW I should push the weld in a straight line with no oscillation? or very slight oscillation? or weave or what? I know that I can probably produce quality welds either way but I guess I'd rather practice the way that will produce the strongest quality weld most often.


I find that if I just push the weld in a straight line with no oscillation that my weld bead gets too tall and if I weave slightly it helps flatten it out. is that incorrect?

[davejurek]

No, I got my gauges mixed up. The plate I'm welding on is very close to 1/16" thick.

That does lead me to this question, what's the rule of thumb for thickness of metal for 023, 030, and 035 wire?

Is the HAZ normal for the 1/16" thickness? In each of these samples, I'm pulling the weld.

Dave

[Dan]

Originally posted by davejurek
No, I got my gauges mixed up. The plate I'm welding on is very close to 1/16" thick.

That does lead me to this question, what's the rule of thumb for thickness of metal for 023, 030, and 035 wire?

Is the HAZ normal for the 1/16" thickness? In each of these samples, I'm pulling the weld.

Dave

Dave

Push the weld puddle on sheet metal. .023 wire is still too small for 16 ga. . Im attaching a chart with suggested wire size for material thickness. Remember, using the proper wire size will help you create a more consistent welds.

[Roger]

Nice chart that I am printing.

I've noticed the charts provided with welders tend to have one size wire fits wider range or all for small welder. Your chart fits my practice unless I'm lazy. 22 ga. with .030 fluxcore wire is possable but would much easier with solid wire. I have even tried welding 24 ga steel with .030 fluxcore wire using short manual pulses but more of a stunt than practical.

[davejurek]

Thanks for the table. I printed it out and stuck it on the inside of my welder.

I measured the thickness of the metal I'm welding on at 0.080 - 0.085 inches. 14 gauge?? (Anyone have a gauge thickness guide?)

I changed my wire to 030 and I definately could tell a difference. The weld seems to penetrate much better now. As before, I've attached some samples.

This one is some straight lines with 030 wire. The first two are at a heat setting of one (23.1 no load voltage) while the last three are at a heat setting of two (25.3 no load voltage). In the outer welds, I moved the gun in a straight line while the inner welds were made using a circular motion. My wire feed rate is at the #2 setting, and according to the table in my owner's manual, that should be near 70 amps with 030 wire.

http://www.knology.net/~davejurek/images/PC1200013.JPG

This weld I made using a circular motion technique. I didn't quite get the feed rate right until about half way thru the weld. I was able to dial it in by slightly lowering the feed rate. The transition is very obvious.

http://www.knology.net/~davejurek/images/PC120014.JPG

And lastly, another t-joint weld, this time moving the gun in a weaving motion.

http://www.knology.net/~davejurek/images/PC120002.JPG

I used the push technique for all of these welds. Does it look like I've got the right heat setting? Welding with the thicker wire allowed me to "bite" into the metal much easier.

Keep the feedback coming. It appears to be working!!!!! :D :D

Dave Jurek

[Rocky D]

Originally posted by davejurek
Thanks for the table. I printed it out and stuck it on the inside of my welder.

I measured the thickness of the metal I'm welding on at 0.080 - 0.085 inches. 14 gauge?? (Anyone have a gauge thickness guide?)

I changed my wire to 030 and I definately could tell a difference. The weld seems to penetrate much better now. As before, I've attached some samples.

This one is some straight lines with 030 wire. The first two are at a heat setting of one (23.1 no load voltage) while the last three are at a heat setting of two (25.3 no load voltage). In the outer welds, I moved the gun in a straight line while the inner welds were made using a circular motion. My wire feed rate is at the #2 setting, and according to the table in my owner's manual, that should be near 70 amps with 030 wire.

http://www.knology.net/~davejurek/images/PC1200013.JPG

This weld I made using a circular motion technique. I didn't quite get the feed rate right until about half way thru the weld. I was able to dial it in by slightly lowering the feed rate. The transition is very obvious.

http://www.knology.net/~davejurek/images/PC120014.JPG

And lastly, another t-joint weld, this time moving the gun in a weaving motion.

http://www.knology.net/~davejurek/images/PC120002.JPG

I used the push technique for all of these welds. Does it look like I've got the right heat setting? Welding with the thicker wire allowed me to "bite" into the metal much easier.

Keep the feedback coming. It appears to be working!!!!! :D :D

Dave Jurek

That last shot looks like you've got it! BTW, the 'T' joint is called a fillet.

My thickness gauge shows 14 gauge material as .0781".....the mills hardly ever get it right on, so if you measured .080" then that would indeed be 14ga.

Now go practice!

[davejurek]

One thing I noticed while doing the fillet welds is that I'd get some popping when I crossed the 90/gap. Not all the time, but occasionally. Is this due to the speed at which I'm weaving or the speed I'm moving the gun?

When I get home, I'll post some pictures of the backside of those same welds. I showed someone here at work and he didn't think I got enough penetration on those welds.

Dave Jurek

[Rocky D]

Originally posted by davejurek
One thing I noticed while doing the fillet welds is that I'd get some popping when I crossed the 90/gap. Not all the time, but occasionally. Is this due to the speed at which I'm weaving or the speed I'm moving the gun?

When I get home, I'll post some pictures of the backside of those same welds. I showed someone here at work and he didn't think I got enough penetration on those welds.

Dave Jurek

The popping could be caused by unsteady movement. It happens to me sometimes, too. Ya move too quick, for a split second, and it pops.

[davejurek]

Okay. Here's a shot of the back of the last picture above. Comment I got was I didn't have enough penetration. Do I need more gap or more heat or both?

http://www.knology.net/~davejurek/images/PC160014.JPG

Dave

[Rocky D]

Originally posted by davejurek
Okay. Here's a shot of the back of the last picture above. Comment I got was I didn't have enough penetration. Do I need more gap or more heat or both?

http://www.knology.net/~davejurek/images/PC160014.JPG

Dave

I don't really see anything wrong, here. You won't penetrate a fillet on that steel...you don't need to. If anything, you could put a little more steel into the weld....you can do that by going slower, or increase your wire feed, or both. As I said before, looks OK to me.:)