Welding question

mbalbritton

mbalbritton

#@$%!
Joined
Mar 22, 2005
Location
Lakeland, FL
I am using a Hobart 135 120v flux. I'll be welding a line with everything going along just fine and then it will jump into a Zap zap zap instead of bacon frying sound. I stop, start again and it will be fine for another 10 seconds then start it again.

Last time this happened it was because I was at the end of a spool and it wasn't feeding clean. New spool cleared that up. Not the case this time.

Thoughts?


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Make sure the whip is as staight as possible. Does that welder have the ability to add tension to the drive mechanism? If you alter the settings and weld something different does it persist?

Is the standoff distance different when it zap zap zaps? I'd guess you are further away than when you started. I'm no pro welder either.
 
I've had a similar thing happen when there was a tiny piece of spatter stick to the edge of the tip where the wire feeds out.
 
check your power supply.

I've had similar issues, I have a power box on the end of a 10ga cord lead, the box was several years old, been used and abused, I found that the outlet had gotten wet and cooked itself. still worked, until it got hot again (seconds of use)
rebuilt the box and checked all the connections upstream. better now

also, if you hit duty cycle often and trip the breaker internally, the breaker gets weaker and will trip more quickly or cause other issues
 
My old Hobart every now and then used to change its wire feed speed at the rollers. Ended up being crappy cheap wire. Never buy crappy cheap wire.
 
Depending on how much wire it's had run through it, the liner in the cable could be worn or damaged causing it to bind or drag. I had to put a new liner in my old Lincoln promig 135, that got it going smooth again til something else internally burned up about a year later.

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Good things to check.

Welder is probably 6-7 years old, but probably only about 3-4 small spools ever run through it. It's one we have at the office, but I'm the only one who knows how to use it (relatively speaking).

The wire is from McMaster Carr, expensive but probably not high grade.

I am running on an extension cord of sorts. One of those long work table length power strips that probably has light gauge wiring.

There is a tensioner and it's set fairly loose.

I might have hit duty load burning 3/8" material on setting 4 (highest). But no one bead was more than 20 seconds if I had to guess. Didn't happen every time. But seemed to happen more frequent the more I used it.

Whip was relatively straight with no twists. And I was pretty consistent at about 1/2" from top to metal.

I'll try it again tomorrow and see what I can determine.


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mbalbritton said:
Good things to check.


I am running on an extension cord of sorts. One of those long work table length power strips that probably has light gauge wiring.

I might have hit duty load burning 3/8" material on setting 4 (highest). But no one bead was more than 20 seconds if I had to guess. Didn't happen every time. But seemed to happen more frequent the more I used it.
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I'd open up that power strip, and not be surprised finding melty stuff inside.....
 
Blkvoodoo said:
I'd open up that power strip, and not be surprised finding melty stuff inside.....
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X2. Get a good heavy gauge extension cord. If it doesn't have to be very long they sell 6' cords for window unit AC at Lowes

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Power supply and or duty cycle given all the mechanical checks out. Look on front of machine for its rated duty cycle or output. I highly doubt it is very good at its max output. I'd ass-you-mate it's 40 percent tops. If it was 60 percent on that little bugger I'd be highly surprised. I have seen some low end stuff at 20 percent at wot.
 
WARRIORWELDING said:
Power supply and or duty cycle given all the mechanical checks out. Look on front of machine for its rated duty cycle or output. I highly doubt it is very good at its max output. I'd ass-you-mate it's 40 percent tops. If it was 60 percent on that little bugger I'd be highly surprised. I have seen some low end stuff at 20 percent at wot.
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It's a 20%. And it's a Hobart 125. Not a 135 like I thought.


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frankenyoter said:
Correct me if I'm wrong, but if it's duty cycle won't it trip the internal breaker and shut off the current?
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If the power supply starts heating up, it may start to taper off output current long before it trips from thermal protection. Depends on how crappy the power supply design and electrical components are. Power supply output regulation with temperature is a big part of proper design.

That's all the explanation I can offer. I know more about power supply design than about MIG welder troubleshooting.
 
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Fabrik8 said:
If the power supply starts heating up, it may start to taper off output current long before it trips from thermal protection. Depends on how crappy the power supply design and electrical components are. Power supply output regulation with temperature is a big part of proper design.

That's all the explanation I can offer. I know more about power supply design than about MIG welder troubleshooting.
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Cheaper, low and smaller units do exactly this and litterally taper down out put. Some if your lucky just hit a thermal shut down rather than give you crappier out put. A larger machine would have stuff like fan on demand and a thermal reset with an actually manual trigger. Most in this range just give crappy results until a thermal type fuse opens then you get to rest like it or not. Worst part they usually break down over time and are not really sensitive enough to prevent long term damage from repetitive WOT.
 
mbalbritton said:
Surprisingly enough... The power strip is wired with solid core electrical and hard wired into the wall box.
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Yeah but what gauge? You'd want it to be rated for 20A draw, so it needs to be at least 12g.

I'd try plugging it in directly (bypass the strip) and see how the behavior changes.
 
RatLabGuy said:
Yeah but what gauge? You'd want it to be rated for 20A draw, so it needs to be at least 12g.

I'd try plugging it in directly (bypass the strip) and see how the behavior changes.
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That's not going to sufficiently restrict the welder though, as the wire current rating is based on temperature rise for continuous duty (I know you know this, some may not). A slightly smaller wire gauge is either going to deliver enough current or it isn't; it's not going to work properly for 10 seconds and then stop working. The temperature coefficient of copper is far too low to have a change in wire resistance that fast from self-heating, especially if the wire size is even remotely in the proper neighborhood. If it's marginal and can't supply enough current, it would be marginal as soon as the trigger is pulled.

Yes, the wire should be sized properly for current draw, but it's not going to cause the problems mentioned. I'm not trying to be argumentative, but it doesn't seem to fit the symptoms.
 
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Fabrik8 said:
That's not going to sufficiently restrict the welder though, as the wire current rating is based on temperature rise for continuous duty (I know you know this, some may not). A slightly smaller wire gauge is either going to deliver enough current or it isn't; it's not going to work properly for 10 seconds and then stop working. The temperature coefficient of copper is far too low to have a change in wire resistance that fast from self-heating, especially if the wire size is even remotely in the proper neighborhood. If it's marginal and can't supply enough current, it would be marginal as soon as the trigger is pulled.

Yes, the wire should be sized properly for current draw, but it's not going to cause the problems mentioned. I'm not trying to be argumentative, but it doesn't seem to fit the symptoms.
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What about the temp rise and subsequent current limitation within a socket? If there's a loose/tarnished connection in the power strip or wall outlet, wouldn't the temp change be more rapid and the conductivity issues compounded by the movement of the terminals in the socket?

Brent, something else to check is the contact tip. If you haven't changed it lately, try that. When they get dirty or scarred up inside, the temperature change can cause them to tighten up on the wire. Let it cool for a minute and it works fine for a little while. Also, why would you buy wire from McMaster, except for the fact that you probably spend tens of thousands with them annually. I've never priced it through them, but it seems they'd be about the highest price around. Hit the Airgas down in Colfax. And like everybody else said, build or buy yourself a good 10ga SOOW extension cord with heavy duty plugs on the ends. Put the welder on a 20A circuit.
 
catfishblues said:
What about the temp rise and subsequent current limitation within a socket? If there's a loose/tarnished connection in the power strip or wall outlet, wouldn't the temp change be more rapid and the conductivity issues compounded by the movement of the terminals in the socket?
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Yes, exactly. If there was a problem with current delivery because of contact resistance, it would be very fast and not take 10 seconds to show itself.
 
catfishblues said:
Brent, something else to check is the contact tip. If you haven't changed it lately, try that. When they get dirty or scarred up inside, the temperature change can cause them to tighten up on the wire. Let it cool for a minute and it works fine for a little while. Also, why would you buy wire from McMaster, except for the fact that you probably spend tens of thousands with them annually. I've never priced it through them, but it seems they'd be about the highest price around. Hit the Airgas down in Colfax. And like everybody else said, build or buy yourself a good 10ga SOOW extension cord with heavy duty plugs on the ends. Put the welder on a 20A circuit.
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new Tip is probably due.

McMaster Carr because we have a business account with them and I can just call them and have it next day.
 
My HD 110 90a unit will do that if the tip if dirty or I buy a pack of tips every roll.. other than that my wire tensioner failed entirely and was fixed with a bracket and a new bolt, by other than that no problems.. Hobart should be marginally better quality than HF. I did notice differences in cheap wire from TSC and Lowe's compared to welding shop or hardware store "hot max" brand (used to be forney) I think it had to do with my welder being AC and the others were DC wire
 
a_kelley said:
My HD 110 90a unit will do that if the tip if dirty or I buy a pack of tips every roll.. other than that my wire tensioner failed entirely and was fixed with a bracket and a new bolt, by other than that no problems.. Hobart should be marginally better quality than HF. I did notice differences in cheap wire from TSC and Lowe's compared to welding shop or hardware store "hot max" brand (used to be forney) I think it had to do with my welder being AC and the others were DC wire
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Altho not AC vs. DC ......
Oh yes, forgot about this topic. Most definitely a subject matter to check. Using Fcaw or flux core some cored wires are manufactured to run Dcen, while some are Dcep. Reverse or straight polarity. Hardwires in Gmaw all run Dcep. Using the wrong polarity with a wire type deffinately screws the arc characteristics up.
 
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