I totally agree that once you get some time under the hood the settings are more guidelines and technique is the name of the game in the end. That's when the art part of it comes into play IMHO.
-
Scam Alert. Members are reminded to NOT send money to buy anything. Don't buy things remote and have it shipped - go get it yourself, pay in person, and take your equipment with you. Scammers have burned people on this forum. Urgency, secrecy, excuses, selling for friend, newish members, FUD, are RED FLAGS. A video conference call is not adequate assurance. Face to face interactions are required. Please report suspicions to the forum admins. Stay Safe - anyone can get scammed.
Best gas for mig Welding sheet metal?
- Thread starter Susquatch
- Start date
At the end of the day, its really about developing technique and knowing your machine. I think the point I was trying to make before, was that sometimes technique has to take over, and that ideal machine settings can change during the course of a weld or job.
As an auto mechanic, a lot of the welding has to be done where you can't see the weld. Exhaust, for example. Welding the top of pipe joints. Sometimes i use a mirror, sometimes i just listen. Building out exhaust studs in cylinder heads for extraction, lots of times you gotta aim the gun where you cant really see.
Sheet metal is more foregiving in way, as strength really isn't the concern. Not like structural steel anyway. Figure out what works and just as importantly, what doesn't. In structural welding, you really don't want to find out what doesn't work.
As an auto mechanic, a lot of the welding has to be done where you can't see the weld. Exhaust, for example. Welding the top of pipe joints. Sometimes i use a mirror, sometimes i just listen. Building out exhaust studs in cylinder heads for extraction, lots of times you gotta aim the gun where you cant really see.
Sheet metal is more foregiving in way, as strength really isn't the concern. Not like structural steel anyway. Figure out what works and just as importantly, what doesn't. In structural welding, you really don't want to find out what doesn't work.
I see. So there are no crazy high voltage spikes despite the arc. That just seems odd to me. I'll try it with a cheap Chinese meter I have first. Then maybe I'll use my fluke or a scope.
If I recall correctly the voltage was steady so long as I held the gun at a consistent distance from the work.
That makes sense, because current is flowing through the arc at that point. But how do you adjust and measure voltage before you start the arc?
My machine only has four settings which are for different metal thicknesses. I needed to know what voltages they put out. I just hooked up the meter and welded a few inches while watching the meter. I noted the voltage range then went to the next setting and did it again till I had the voltage range for each setting.
I have no idea how a light is supposed to help when you already have a high current arc going on. A white chalk line might help but I'd be worried that it would contaminate the weld. Ya, I know.... I worry too much!
I have some "bird baths" of my own here. I don't tell anybody that I did that.......
We posted at the same time. You were measuring closed circuit voltage then, which is a good indicator of how the machine is performing based on how you weld. Stickout, etc plays a factor
So what are the typical OCVs and what happens to that voltage as the arc starts to cut in and out?
Yes I forgot to mention stickout and its affect on voltage.
Good discussion going on here, I'm learning things. Great videos showing the transfer method in that link complete with setup parameters.
I think the chart you're referring to is this:
I bumped into it on a welding forum.
I wonder if the machines that have set detents (vs CV) have rotary switches with discrete connection or if they're potentiometers with a mechanical detent....
I think I know what the short circuit transfer method "feels" & looks like, it's familiar from doing thin/sheet metal work. At times I can feel the electrode contacting the work piece.
I'm going to have to try some of the settings from the videos to replicate the globular and spray modes. I've probably worked that way but not by intentional setup. Interesting that after all this time seeing reference to the various modes this is the first I've actually seen it spelled out and with specific setup parameters. Thanks @ThirtyOneDriver for the link.
Following some of the discussion in this thread, I see that we have a common challenge seeing & following the intended bead path, for me it's the illumination contrast between the weld arc & the work piece, especially in lighter material/sheet metal. I try and plan ahead what path I'm going to take and try to follow it. That can be difficult when it's an irregular shape or going around corners on tubing etc.
Always learning!
D
Last edited:
its been a few years since i worked with a machine where OCV was actually a factor, and ive never measured it on my own machines. Some welders are constant voltage/constant current, but thats usually above hobbyist grade, last time i looked.
It really doesn't matter. If we are talking MIG, my early 90's Lincoln sp170 has 5 heat settings, and infinite wire speed. a combo of both always works within the machines limitations.
for spray transfer, you need a mix of 80% argon, and usually a 200+ amp mig. Its a thing of beauty for sure.
ThirtyOneDriver
Johnathan (John)
Spray transfer is awesome, but ~ 12 months of welding training across stick, MIG, and TIG, there was only the one opportunity that it was feasible. Our welding program reflected the work we were likely to need to perform, so a lot of steel 3/8, 1/2, 3/4, 1" one mock-up crack repair in 3" armour, aluminum was 1/4" or 2" (double bevel, vertical up... this weld created blisters on the back of everyone's hands despite multiple layers of gloves and heat shields). We also did some stainless and other stuff, and I received other certifications (4130 tubing) from other schools for more specific reasons.
In practice (20 years of welding but not everyday) I've never had the opportunity to get into spray and rarely have worked on things that I could get/want globular spray transfer - keep in mind that you need to be pushing >24 or 24.5 volts and Constant Voltage to reach either of these methods... I'm not sure how many of the machines I've used were even capable... until this thread, I didn't know it needed to be a CV machine... and assumed that the machines that were portable enough to take to the job just didn't have the power to get there.
@Tecnico - that wasn't the chart I was thinking of, but after seeing it I'm kicking myself for not buying the 180C in the area for $700... I can weld 0.095" wall tubing on the retail 180s w/ both knobs maxed out (0.023" wire) so I'm making an educated guess that it's not capable of hitting 25v or 500 ipm... actually, the voltage knob doesn't go past "E" which on the 180C chart reads 19.7v ... that seems about right for what the retail 180 puts out. BTW, I didn't know that welding could be performed at 10v (setting "A")... it's kind of wild to see that low of a number on a chart like that.
In practice (20 years of welding but not everyday) I've never had the opportunity to get into spray and rarely have worked on things that I could get/want globular spray transfer - keep in mind that you need to be pushing >24 or 24.5 volts and Constant Voltage to reach either of these methods... I'm not sure how many of the machines I've used were even capable... until this thread, I didn't know it needed to be a CV machine... and assumed that the machines that were portable enough to take to the job just didn't have the power to get there.
@Tecnico - that wasn't the chart I was thinking of, but after seeing it I'm kicking myself for not buying the 180C in the area for $700... I can weld 0.095" wall tubing on the retail 180s w/ both knobs maxed out (0.023" wire) so I'm making an educated guess that it's not capable of hitting 25v or 500 ipm... actually, the voltage knob doesn't go past "E" which on the 180C chart reads 19.7v ... that seems about right for what the retail 180 puts out. BTW, I didn't know that welding could be performed at 10v (setting "A")... it's kind of wild to see that low of a number on a chart like that.
Wow. That's great info.
My wire welder just happens to be a Lincoln 180. But I doubt it's a 180C. The inside panel says 180T.
The feed dial is continuous but does not start at zero. The control dial has detents but I don't know if it is a reostat with detents or a rotary switch. I might take a peek under the cover later today if it's easy to do.
The drive wheels are metal not plastic.
Here is a photo of the settings chart.
I have welded with it but it ain't pretty. My welds look like the Rocky Mountains not beads. I blow through sheet metal like it was saran wrap and thin stock like it was tin foil. I do ok on thick plate but it ain't pretty. The grinding wheel on my hand grinder gets lots of exercise.
I can stick weld half decent but again only on thicker plate and it ain't pretty. To be truthful, I do a better job with old style oxy-acetylene gas.
Back in the day, we had a mechanic who could weld aluminium tin foil and lay a bead on plate as smooth as spreading caulking with an electric gun. Nobody else welded because it was always..... shall we say embarrassing..... (that's the polite word for it). Today, I have a built in fear of welding.
But several people have volunteered to help get me going. I doubt it's a knowledge thing for me but I don't know what I don't know so who knows.... Prolly more of a hands on experiencial learning thing. I guess we will see. I am motivated and willing to try.
DPittman
Ultra Member
I saw some post " A grinder and paint makes me the welder I aint".
ThirtyOneDriver
Johnathan (John)
@Susquatch - the main visual difference from the 180C to the retail 180s was the billet aluminum drive system (pictures) - MOST 180 retail welders have some sort of composite components (drive wheels are still steel)... my retail 180s have more plastic than the model I took the image from.
