[j351]

I've been reinforcing my car by welding 1/8" tubing into the floor pan with a Mac 110v MIG welder (using argon). I had no problem welding the part I was able to do from above then started on the bottom and got halfway through before it became impossible to weld. The welder tip started spewing out molten globs of metal that fell downward and wouldn't penetrate the metal overhead anymore. I already welded overhead (90 degree joint) for half an hour without a problem. I had a good ground which I tried moving to different spots, plenty of gas left in the tank, and replaced the tip on the gun. I turned voltage and wire feed up and down and nothing helped. The metal was no dirtier than the spots I already welded, it was relatively clean with no paint near the edge.

Any ideas on what I could be doing wrong or if something could be wrong with the welder? I'm near the end of a new roll of wire (Lincoln .030 MIG wire) I just put in it in the morning, now there's maybe a few feet left on the roll. The rest of the roll burned in fine from underneath until now when it suddenly stopped burning in and dripped down instead.

[noddybrian]

It's always easier to see than describe - but it sounds like a typical scenario when the wire speed is too low for the position & voltage ( overhead being the least forgiving ) - the fact you tried altering this means you understand the likely cause but there are numerous machine issues that can cause wire speed fluctuation - my guess that's the problem - here are a few thoughts on common causes & the small 110volt machines do seem prone to poor wire feed issues.

Different gun angle due to position showing up liner wear issue / torch hose bent at acute angles due to access
Stick out length more critical overhead - variation due to difficult viewing angle / body position
Wire feed rollers slipping due to extra liner drag or even bad contact tip
Less likely - but on non precision wound wire it's possible to get a loop of wire over the one that's feeding so it's being dragged under / against other turns causing excessive drag
Wire feed brake setting too high or rust / contaminants are causing a tight spot giving intermittent wire variation as roll turns.
Strong magnetic field somewhere close

I'm sure other members will add to this - maybe with more insight - but this is where I'd start looking.

P.S. Welcome to the forum.

[j351]

Thanks for the welcome.

I've tried a variety of gun angles to no avail. Maybe I'll try moving the hose around but it didn't seem to be bent at an acute angle. I tried doing it in the same spot I already welded and it won't work right either. I stopped for a few minutes, went back to it, and all of a sudden couldn't burn in anymore. The metal isn't perfectly clean but it's no worse than a ton of spots I've already welded with no issue on the car. I just put a new contact tip in too with no difference.

There's only a few coils of wire left on the roll so that might be the issue. I'm going to pick up a new roll and give it another shot today. The welder is a nice Mac 130A machine that sold for around $800 new so it's not like I'm using some cheap harbor freight one.

[j351]

Here's photos before and after the problem and a photo of the welder tip. I tried welding downwards too and the same thing happens. A giant ball of molton metal forms on the tip of the gun. I tried turning wire feed down again and still no difference. I've tried everything I can think of, maybe something crapped out in the welder?

[Antorcha]

Wind---breeze. You lost shielding. Try turning up the gas flow to 25 or so. Small machines should use CO2, not mixes.

[noddybrian]

Well I don't want to hate on your welder - but machines from Mac / Snap-on are typically overpriced & not that great a build - that said when only trying sheet metal they should do a decent job.

I don't know why anyone would think small migs should use just Co2 - yes it's cheaper than argon mix for occasional hobby use - but I have yet to see any welder that did'nt work better with mix than straight Co2 - so I beg to differ on that comment - if you have or can afford to use argon mix then I would - I would also say on small machines with limited voltage that 95 / 5 is better ! - one or two more open minded members have even risked agreeing with me on that !

Lack of shielding is possible - but from what I can see in the picture I'm not sure - it does'nt have the classic aero look - also the heavy smoke on the nozzle looks somewhat like heavy contamination burning off - like you have some galvanized material.

You have'nt by chance got some plated / galvanized or non steel there - does this problem happen anywhere on the car or just on that piece of sheet ? are you near a factory seam - is there any chance your burning seam sealer out from a joint - that stuff messes with a weld.


As you were close to changing wire anyway may I suggest you get a fresh roll anyway take the machine indoors to eliminate wind - check gas flow by ear if experienced or with pea shooter gauge - find a nice new or clean some sheet & try again 1G ( downhand ) with the torch hose out straight & see what it goes like - if you get a good weld by elimination you hopefully see what the problem was - if not come back with a further report & see what the members can figure.

[j351]

There's no wind, I'm doing this inside a garage with the door shut. I also didn't lose shielding, I even tried turning the gas up and it made no difference. I ran out of gas before and it acted way different. None of the variables (as far as I can tell anyways) have changed and suddenly I was no longer able to burn in and the wire keeps balling up.

I'm adding mild steel to existing sheetmetal in the car. There's no galvanization on anything, just some weld-through primer on some of the tubing. Whether or not I'm welding on a spot with the weld-through primer doesn't seem to make a difference.

I'm also using straight argon or a 75/25 mix I believe. It worked fine for the rest of the welding so I can't see that being the issue. It's my buddy's welder that has worked fine for him all along.

I put a new roll in today and it didn't seem to change anything. Then I messed around with the tension on the wire feed and played around with wire feed and voltage settings and got a section of it welded ugly (way worse looking than sections I already did) but solid enough. The welds will be stronger than the sheetmetal I'm attaching to the tubing anyways. Then it went back to balling up and not burning in - I tried to add a 1.25x1.25x1/8" tube brace to the chassis off of the tube I already welded in and can't get it to burn in worth a damned. It won't even stick half the time.

[Superiorwelding]

One of your problems is using straight argon, big no no for mig welding! You need that co2 for penetration. Second you slain you are turnings down the wire speed when you should be turning it up for overhead. A general guideline is increase wire speed 10% when switching to overhead. Balling up like that is a sign of to much voltage and not enough wire speed therefore the wire will melt back to the tip faster than the wire can push it away.
Have you tried the same settings in the flat position? This would tell me if the machine is fine or not. If you can run a respectable bead flat than I would say it is the two items mentioned.

I see nothing wrong with mix gases for 110 welders. True you can get more penetration with the co2 but a 95/5 oxygen mix could put one in spray or at least globular. I know a weldors that only runs a oxygen mix in his 110v and it does fine, not saying this is the answer here though.
-Jonathan

[j351]

Well it worked fine for 3/4 of the welding I had to do then suddenly stopped, so I don't think the type of gas is the problem when it already gave me satisfactory welds. I've both turned the wire speed up and down, I've tried every mix of settings I could. I briefly tried it in a flat position and it didn't seem to be working properly that way anymore either. It just suddenly became unusable without anything obviously changing.

I'm honestly thinking something is crapping out in the welder. I did like 14ft of butt welding (12-14 G sheetmetal to 1/8" tubing) from above and like 5ft of seam welding from underneath before it stopped welding properly.

[Superiorwelding]

With that said I think I agree on the machine going bad. Anyone else want to chime in?
-Jonathan

[Otto Nobedder]

Since fresh wire didn't solve it, and the problem seems to have come on suddenly, I tend to agree with the possibility of "arc-blow", from welding on magnetized metal. What's normally installed/routed in the weld area? Likely examples that could magnetize the steel could be Subwoofers, amplifiers, heavy power and ground cables (especially if you have a rear-mounted battery).

Grind out an inch or two of the existing good weld and re-weld it (or just set up something similar with scrap) with the previously working settings, to prove everything else is functioning as it was. Then, the options are all specific to the problem area, meaning either arc-blow or some sort of contamination you didn't see, like weld-through primer burying some contamination original to the manufacturer.

If you can't get it to weld overhead at all, and it gives trouble in other positions, see how much gas is left in your tank. Moisture in the gas becomes more apparent as your gas gets low, but this usually comes on slowly.

Steve S

[j351]

I already said it won't work properly in areas I already welded. There haven't been any speakers near the area or a rear mounted battery or anything. There will be a rear mount battery soon but not yet...

The gas tank is now down to 500psi but this started when it was around 1000. It was 2000psi full.

[Otto Nobedder]

Your supplier should be willing to analyze your bottle at no charge. That makes the "moist gas" theory cheap to test, and if it's the case, they'll usually swap you a full bottle at no charge.

Other things to check include the connections under the machine cover for the ground terminal and wire-feed. If either connection is loose or has developed internal corrosion, you can have issues, as well.

I'm trying to dig for answers that are NOT a machine problem...

Steve S

[MinnesotaDave]

Well it worked fine for 3/4 of the welding I had to do then suddenly stopped, so I don't think the type of gas is the problem when it already gave me satisfactory welds. I've both turned the wire speed up and down, I've tried every mix of settings I could. I briefly tried it in a flat position and it didn't seem to be working properly that way anymore either. It just suddenly became unusable without anything obviously changing.

I'm honestly thinking something is crapping out in the welder. I did like 14ft of butt welding (12-14 G sheetmetal to 1/8" tubing) from above and like 5ft of seam welding from underneath before it stopped welding properly.

I'll take a wild guess, did you pay attention to duty cycle during 19 feet of welding with a little 130 amp machine?

I only ask because you didn't mention over what time period the welding was done.

Edit: not sure if I missed it, does it weld perfectly in the flat position currently, or is it all bad?

[j351]

I checked the connections and they seem fine.

I doubt I overloaded the duty cycle, this was done in several hours over a few days. Not to mention I had to stop a lot to avoid blowing through the sheetmetal. The longest joint I did at once was maybe 2". It doesn't seem to work right doing flat stuff anymore either. I'm going to try messing with the wire feed adjustments more tonight. Must be slipping or something.

[MinnesotaDave]

I checked the connections and they seem fine.

I doubt I overloaded the duty cycle, this was done in several hours over a few days. Not to mention I had to stop a lot to avoid blowing through the sheetmetal. The longest joint I did at once was maybe 2". It doesn't seem to work right doing flat stuff anymore either. I'm going to try messing with the wire feed adjustments more tonight. Must be slipping or something.

This winter I had a neighbor bring me his MacTools 140 mig - wouldn't weld. Started as intermittent, then quit.
When I tested it, his mig gun cable had broken at the end near the machine - pushing it together and holding it, started welding again.

His was mainly used for body work and the constant tugging it into all different positions finally broke the gun cable at the crimp (the copper color band).

So if your intermittent welding turns into no welding output - it's an easy place to start checking.
It had voltage to the studs at the machine, none at the tip.

[MinnesotaDave]

Additional thought (I overlooked simple stuff).

In your third pic it looks like the wire is much smaller than the hole it's coming out of - it that a camera optical illusion?

If not, either your contact tip is worn out (oblong hole) or there is an .045 tip in there.

Have you tried a new contact tip?

Also, why is the tip recessed so far, I generally run very close to flush.

[j351]

It doesn't seem like I'm losing voltage so a bad connection doesn't seem like the problem.

I put a new .030 contact tip in and I'm running .030 wire. I'm not sure why the tip is recessed so far, that's how it was when I grabbed the welder from him.

[Braehill]

First let me say that I'm in no way an expert on Mig welding, but here's a problem that I had when I first got my 180 Lincoln. If you look in the picture in Dave's post you'll see the holes in the part that goes in the machine, I hadn't pushed it far enough in to get full flow on the shield gas and ended up with welds that look similar to yours. If the bolt that goes into it is a lttle loose it can be pulled out enough to restrict your gas flow, with the O-rings blocking it. Also check the O-rings for cracks or a tear that can bring in atmosphere by siphoning.

Just a thought.

Len

[MinnesotaDave]

First let me say that I'm in no way an expert on Mig welding, but here's a problem that I had when I first got my 180 Lincoln. If you look in the picture in Dave's post you'll see the holes in the part that goes in the machine, I hadn't pushed it far enough in to get full flow on the shield gas and ended up with welds that look similar to yours. If the bolt that goes into it is a lttle loose it can be pulled out enough to restrict your gas flow, with the O-rings blocking it. Also check the O-rings for cracks or a tear that can bring in atmosphere by siphoning.

Just a thought.

Len

Excellent reminder - both my brother and my best friend pulled out their cable enough to malfunction within weeks of each other.
Both machines were Millers.

[j351]

Well it seems the problem is that I didn't put enough tension on the wire feed mechanism.

Then I killed power at the 1 bay garage I rent and can't find any breakers off in the house it's connected to...

[noddybrian]

Glad you got it figured out - it's harder to diagnose from a description than actually seeing / hearing it - but I did think a wire feed issue was the most likely all along - hope you solve the wiring fault soon & get back to your project.

[danielbuck]

for overhead, I generally turn the wire speed up a bit, and put a bit more stick out than normal. Turning just the voltage down a bit would accomplish mostly the same thing I guess.