Trying to improve my MIG welding

[Matt Pascoe]

I've been welding ocasionally for a couple years now. First with a Miller 135 and now with a Miller 251. I typically use the chart on the welder to determine my voltage and wire speed. It gets frustrating because the results seem to vary wildly even with the same settings. I cant get a feel for what more wire speed or voltage is doing for me.

I DO know the feel when things are going well. The bacon sizzle and consistent puddle pushing along... feels great. But then the sizzle turns to pop pop pop and things turn to shiat.

Today I needed to repair a scraper box on one of our small tractors. 4x6 .25" plate scabed onto the side of the .25" steel box to reinforce an area that was cracking.

Heres what I'm using:
Miller 251
.035 wire
Argon CO2 mix
21.5 V
290 speed

I was welding outside and the Santa Ana winds were gusty (calm than 20knt gust)

First horizontal weld seemed good:

Then vertical went to crap:

Same settings, why is it running?
I can clearly see when the wind gusts blow away my gas the weld bubbles. But that shouldnt explain the runny weld. Also it was popping more then sizzling
Then another vertical:

Seemed better.

Then I tried an area that was not prepped at all just to see what happened:

UGLY

Heres the bottom weld. Again popping. I can see that it was alittle hot... Started melting into the plate:


I play with the voltage and speed but cant seem to get consistent results/changes that let me know whats needed to improve.

I want to get alittle more consistent before I start welding on the Jeep again.

Any comments or opinions as to what I'm doing wrong or how to improve.

Thank alot!

Matt

[mrblaine]

On the verts, point the wire a little more uphill, crank the wire speed up slightly and move down a tad faster.

On the horizontal, slow down your hand travel rate, keep the wire in the puddle slightly longer and turn the heat up a few amps or the wire speed down slightly.

ON the crappy one that you didn't prep. Do I really need to say what to do there?

Oh, until you get really good, start using both hands to steady the gun.

[Matt Pascoe]

Thanks for the pointers Blaine

I really havent been paying attention to direction of travel or angle of the nozzle (pushing/pulling etc). So on verticals I want to aim up but travel down... what about horizontal? Point forward and push?

Also, that last pic, that was a straight edge before I welded it. Is that called undercutting when you melt into the material like that? Is it to much heat or just the nozzle pointed more towards that edge?

Lastly, I usually weld in a pattern. Either a zig zag stitch or a circular movement. Today I was just pushing straight. Does it matter?

I know... I really should take a class

Thanks again!
Matt

[mrblaine]

Originally posted by Matt Pascoe
Thanks for the pointers Blaine

I really havent been paying attention to direction of travel or angle of the nozzle (pushing/pulling etc). So on verticals I want to aim up but travel down... what about horizontal? Point forward and push?

Also, that last pic, that was a straight edge before I welded it. Is that called undercutting when you melt into the material like that? Is it to much heat or just the nozzle pointed more towards that edge?

Lastly, I usually weld in a pattern. Either a zig zag stitch or a circular movement. Today I was just pushing straight. Does it matter?

I know... I really should take a class

Thanks again!
Matt

What you can do is swing by for a 15 min demo and I'll get you started at least on the beginnings of the right road. Let me know when.

[Matt Pascoe]

Theres an offer I'd be a fool to pass on

PM sent

[Allen]

Matt,

Swing by Blaine's and get the free demo. It'll be worth your time.

That said, before you tackle any weld with a greater degree of difficulty than a flat fillet or butt weld, you must first master those. That will do wonders for your welding. It's akin to having never welded before, and picking up a Tig torch and attempting to weld aluminum overhead.....It doesn't work like that for most people.

Interesting though, is that your best looking weld happens to be a V down.

Your pictures indicate that your machine settings are within the ballpark. Maybe a tad on the hot side.....It's really difficult to tell. The edges look sufficiently blended in, but your wire is lumping up in the middle of your weld. So the edges look hot, but the throat looks cold. We'll assume they're cold.....Increase your voltage a notch, or decrease your wire speed a bit.....or do a little of both. If that doesn't do it, as in they look worse, or are definately cold, then add more heat. Then go from there.

Bottom line, the chart only gets you close. Fine tuning is up to you, and will vary with wire selection, shielding gas selection, steel thickness and condition, weld position and so on. For instance, right now I'm constructing a 25 foot radar tower extension to go on top of an existing 40 foot tower. It's a 6 foot by 6 foot by 25 foot rectangle, constructed of 4x4 tubing using 3x3 tubing for cross bracing. Wall thickness is .125 or 1/8. The welder, a MM210 is set for 1/4, and it's working out very well. For me.

Your biggest problem, and likely one of the most common, is inconsistant travel speed. You need to work on that, and that'll come with practice and concentration.

Also, when welding vertical down, aim your nozzle slightly up. As your traveling down, you're actually "pushing" the puddle up, preventing it from running down and globbing up. The machine should also be set slightly colder.....less heat or more wire.

Lastly, most people don't fully understand the 208/240V input on small welders. It is crucial. Check you outlet and adjust the voltage jumper if necessary.

Here's why.....

I was convinced that our MM210 was the biggest piece of **** there was.....It spits and sputters, lays down cold welds.....and then welds beautifully. It was an intermittant thing. I finally got so fed up with it that I checked the power outlet with my meter. (Never take anyone's word on how much voltage is coming out of an outlet ) Our welder was running on 208, but the jumper was set for 240. No wonder it welded like ****.

Allen

[Matt Pascoe]

Allen,
Thanks for the tips

I stopped by Blaines today and think I have a handle on ways to improve. I travel too fast, and havent been paying attention to nozzle direction. I need alot more practice but think I'm on the right road now

I checked my voltage at the outlet and it 240v. The welder has jumpers for 200v or 230v and I have it on the 230v jumper so I think thats right.

Big thanks to Blaine for the hands on training. I owe you one

Matt

[Matt Pascoe]

Todays welding started out UGLY. Pop, pop, pop, spitting, hissing and the weld is covered with a black soot Yesterdays welds with Blaines machine were beautiful, didnt even need cleanup.

So I figured pop, pop, pop meant too cold and I crank up the heat. Went from bad to really bad.

So now I'm thinking I got something really screwed up and start checking for reversed polarity, wrong wire, wrong gas (acetylene right )

Then an idea about the black soot hit me like a glowing cherry sitting on the top of my head... maybe I'm just way too hot?

So I crank the heat down alot and try it again. Bingo. I guess going from an underpowered machine (Miller 135) to an overpowered machine (Miller251) had me all screwed up. I was using the chart to select power and speed, but maybe being at 240V input overpowers the chart settings

Without Blaines help yesterday I'm not so sure I would have ever figured this out. Heres the results:



Think I'm getting somewhere now

[Allen]

Nice improvement.

Allen

[mrblaine]

Originally posted by Matt Pascoe
Todays welding started out UGLY. Pop, pop, pop, spitting, hissing and the weld is covered with a black soot Yesterdays welds with Blaines machine were beautiful, didnt even need cleanup.

So I figured pop, pop, pop meant too cold and I crank up the heat. Went from bad to really bad.

So now I'm thinking I got something really screwed up and start checking for reversed polarity, wrong wire, wrong gas (acetylene right )

Then an idea about the black soot hit me like a glowing cherry sitting on the top of my head... maybe I'm just way too hot?

So I crank the heat down alot and try it again. Bingo. I guess going from an underpowered machine (Miller 135) to an overpowered machine (Miller251) had me all screwed up. I was using the chart to select power and speed, but maybe being at 240V input overpowers the chart settings

Without Blaines help yesterday I'm not so sure I would have ever figured this out. Heres the results:



Think I'm getting somewhere now

Looks much better Matt. Glad I could get you pointed in the right direction at least.

[quadna71]

just wanted to throw out a random thanks for the pics and insight lent in this thread (and all the others that popped on search). i've played around once or twice with a mig at a buddy's house and a stick a few times back home before i entered the service 14 years ago. but - i borrowed a friends mig welder and gave my first real go at it today. it's pretty small - a CH mig that runs on 110v - but uses gas and i have it working okay.

so far - angles are the easiest to weld, slight inclines seem easier to get moving on, and clean metal seems to be the key for me. i'm still getting a handle on the angle of the wire and i also need to keep working on my speed of the hand...but all in all have started to make welds that actually penetrate and overlap pretty decent. again, i know next to nothing - aside from what i read in my hobart welding book from TSC - but i'm pretty excited.

after practicing off and on all morning - i ran my first bead on the jeep. i know have front lower control arm skids. well, one anyways. it's 93+ degrees outside...and time to take a break for water. wish me luck on the other one.

well, just wanted to say thanks to mrblaine, allen, and all the rest who've mentioned tips and such -
chris

[quadna71]

reviving the dead...

my new welder should be here in a few days and i plan on playing around with lots of scrap metal before i even touch a jeep with it. any basic pointers that most seem to overlook? how about a good book that i can pick up in the meantime to help me make the most of my small understanding/experiences with welding?
chris (miller 180 w/AS)

[Allen]

No books that I can think of.

Experience unfortunately is key, that and good instruction.

What problems specifically are you trying to fix?

I am curious about the auto set feature.

I once used a production Miller with a similiar "fuzzy logic", and I didn't really care for it. At least until I found out how to disable it.

I wonder if they've made improvements to the system, or if you can over ride it.

Let us know what you think.