Mig Welding Wire and Type

[glovemeister]

Looking to purchase good MIG welding wire for putting in butted patch panels.

I anticipate that I should use .23 wire. Is there any specific brand, grade or type that I should be purchasing?

Thanks

[DocMel]

For me, MIG is a little too hot for narrow gauge metals such as panels:  You can run spot weld with a MIG on this stuff, but for me, for a bead on narrow gauge sheet metal you really need TIG

[rhamson]

I have been using a .23 wire that has a EG (easy grind) rating on it. It is not recommended for any structural welding but neither is .23. The hardest part is stitch welding with patience. I try to set up a few areas within a couple of feet of each other and move between them to allow for the welds to cool and not warp. TIG is probably better but it has a learning curve that you may not want to try for the first time on your project.

[glovemeister]

For me, MIG is a little too hot for narrow gauge metals such as panels:  You can run spot weld with a MIG on this stuff, but for me, for a bead on narrow gauge sheet metal you really need TIG

Yeah if I had a TIG machine or the know how to run it that wouldn't be a problem. So MIG is the choice.

[DocMel]

There is a reason TIG is used to weld narrow gauge metal.  A MIG, especially while learning, will tend to burn thru car sheet metal and leave you with a big ugly hole.  The heat will also tend to warp the metal way past the area that was being welded, which equals extra body work and labor to get it straight

A MIG can barely spot weld narrow gauge metal, let alone stitch a good long bead, w/burning thru 

Key to a good weld is good penetration:  With a MIG on sheet metal, you will burn thru it trying to do so

[glovemeister]

There is a reason TIG is used to weld narrow gauge metal.  A MIG, especially while learning, will tend to burn thru car sheet metal and leave you with a big ugly hole.  The heat will also tend to warp the metal way past the area that was being welded, which equals extra body work and labor to get it straight

A MIG can barely spot weld narrow gauge metal, let alone stitch a good long bead, w/burning thru 

Key to a good weld is good penetration:  With a MIG on sheet metal, you will burn thru it trying to do so

Docmel,

TIG isn't even close to a choice. Have been running a mig for 6+ years now. Not a fantastic artist with it, but I can make nice looking beads with good penetration, on thicker metals. Gonna invest in a copper backing bar to try to help remedy the problems you are discussing, as well as stitch weld it, and use compressed air to cool welds. Not in a big hurry so I can afford to take my time.

[roadman5312]

Docmel,

TIG isn't even close to a choice. Have been running a mig for 6+ years now. Not a fantastic artist with it, but I can make nice looking beads with good penetration, on thicker metals. Gonna invest in a copper backing bar to try to help remedy the problems you are discussing, as well as stitch weld it, and use compressed air to cool welds. Not in a big hurry so I can afford to take my time.

                   The copper backing bars work great. I have 3 with magnets in them. 

[dutch]

not sure if codes are the same ,or what brands are available in the us, but imo it doesn`t really matter that much for patch work.  I`d just go to a local supplier of welding equipment and get what they sell.  When they supply welding companies, they wont be selling crap wire. 
SG2 code in 0.6mm is what I`d use... not sure what the US equivalent is.
As for Tig,  that`s nice, but if you REALLY want to get the best welds on sheetmetal, A/O is the way to go.

[734406pk]

In my experience of welding sheet metal, MIG has been the preferred method. If you're burning thru, a copper plate and/or machine adjustment will correct this. .023 solid wire with a -6 silicon rating will give the weld puddle more fluid wet out and less grinding. Buy yourself a auto body welding handbook and study up on the process. When you're ready to buy a MIG welder, I would go with a professional unit like a Miller 180 amp with Autoset. Also I have found running the machine on 240 volts gave much better results. TIG is good, but it takes a lot of skill to do at least 3 things at the same time: maintain arc length, control the amperage and probably add filler rod while trying to see. Not easy. Auto darkening helmet is a major plus. Any welding process on sheet metal will cause warpage. A good handbook will show how to minimize the effect. Good luck!

[glovemeister]

                   The copper backing bars work great. I have 3 with magnets in them. 

Had no clue they made such a handy device. Will track those down.

Sure excited to see how they help on this type of metal. Done some sheet before, but it was never anything I cared about too much.

So looking to stack all the odds in my favor for this 71.

[brads70]

I have both mig and tig but used mig for doing my fenders. Just be patient and cool off the weld with a air line before you go on to the next. I can't remember what size wire I used .027 I think?  I've never done much body work before the fender project and I had no trouble with blowing holes? If you hold the mig gun on an angle instead of straight on it doesn't penetrate as much I find.

[glovemeister]

In my experience of welding sheet metal, MIG has been the preferred method. If you're burning thru, a copper plate and/or machine adjustment will correct this. .023 solid wire with a -6 silicon rating will give the weld puddle more fluid wet out and less grinding. Buy yourself a auto body welding handbook and study up on the process. When you're ready to buy a MIG welder, I would go with a professional unit like a Miller 180 amp with Autoset. Also I have found running the machine on 240 volts gave much better results. TIG is good, but it takes a lot of skill to do at least 3 things at the same time: maintain arc length, control the amperage and probably add filler rod while trying to see. Not easy. Auto darkening helmet is a major plus. Any welding process on sheet metal will cause warpage. A good handbook will show how to minimize the effect. Good luck!

73,

Thanks for the reply.

Not a total noob to welding and appreciate the advice. Primarily just wanted to check out what the real experienced body guys are using on their e-bodies. Want to make sure to stack all the odds in my favor.  A 71 chally isn't an average car and not something I want to make a mistake on something as critical as wire type.

If it was any other car I didn't care about, I would just use my .030 and call it good haha.

Will be getting some .023 wire headed this way!

Thanks for the help everyone.

[glovemeister]

I have both mig and tig but used mig for doing my fenders. Just be patient and cool off the weld with a air line before you go on to the next. I can't remember what size wire I used .027 I think?  I've never done much body work before the fender project and I had no trouble with blowing holes? If you hold the mig gun on an angle instead of straight on it doesn't penetrate as much I find.

Brad,

Did you really fab that fender? That is dang fine work.

[brads70]

Yep, It was a lot more work than I anticipated though.

[734406pk]

Sorry about the noob thing, I misread the post. I think Eastwood has some copper backing plates for MIG welding body panels. The magnetic ones are nice when you can't reach inside a door or fender. Good luck with the '71 !