What to buy for panel replacement work?

[Peter57]

Hey Welding Gurus,

I'm trying to assist my son rebuild a very rusty 1968 VW beetle. Problem is that they guy that loaned us a MIG wanted it back too soon. So, now I have to decide what welder to buy. My first question is MIG or TIG?

I've been using MIG with success, although my welds look pretty scrappy. Patience, a 4" grinder and a very light wipe of filler seem to fix the cosmetics. In my youth I accomplished all my panel repairs with oxy and then spent way too long with panel hammers trying to bring things back to shape - but the welds were certainly a lot neater.

So, my dilemma now is MIG or try TIG (which appears to be a little like oxy welding with an arc instead of a flame)?
Then what unit to purchase?

I have a limited budget of course and he's a uni student so his budget is even smaller. I see these units at places like Gasweld, they seem cheap but I expect that they are throw away machines. I want gas MIG of course - tried gas less once a long time ago and never again.

Any advice?

thanks in advance,
Peter

[KBs PensNmore]

I would suggest the MIG, as you are already used to it, TIG has a learning curve, sure, it does do an excellent weld but requires gas, usually argon and wire stub ends all over the floor, hard to weld over head (if required) and has a limited thickness welding capacity. Buying a decent MIG, it has a variable welding thickness, fills gaps easily, minimal distortion. Cooling the short weld with a damp rag helps cut down on distortion. Remember to check out the duty cycle on anything you get. Instead of using grinding discs try using Flap discs, (layers of emery tape overlaying each other), gives a much smoother finish!!!!
As a suggestion, do you have an air compressor? As I would get an air operated tool that bends sheet into a z that helps with replacing panels, it can also be used to remove spot welds on edges. Cut out the area and then run the tool around the inside edge, and drop a new piece into the recess, requires stitch welding only unless it is a structural panel. A crash supply shop should have one of these, or know what they are called, you might find one on EBay.
Kryn

[Karl Robbers]

I would suggest the MIG, as you are already used to it, TIG has a learning curve, sure, it does do an excellent weld but requires gas, usually argon and wire stub ends all over the floor, hard to weld over head (if required) and has a limited thickness welding capacity. Buying a decent MIG, it has a variable welding thickness, fills gaps easily, minimal distortion. Cooling the short weld with a damp rag helps cut down on distortion. Remember to check out the duty cycle on anything you get. Instead of using grinding discs try using Flap discs, (layers of emery tape overlaying each other), gives a much smoother finish!!!!
As a suggestion, do you have an air compressor? As I would get an air operated tool that bends sheet into a z that helps with replacing panels, it can also be used to remove spot welds on edges. Cut out the area and then run the tool around the inside edge, and drop a new piece into the recess, requires stitch welding only unless it is a structural panel. A crash supply shop should have one of these, or know what they are called, you might find one on EBay.
Kryn

Definitely the mig. If your primary use is bodywork then I would suggest .6mm wire however even .9 will not be too bad.
I would echo the advice to use a punch and flange tool, (that's what it's called KB), but use a weld through primer first as it prevents corrosion between the layers, (seam sealer will help too if you can access the back of the panel).
Some use a damp rag to cool as KB suggested, some use a squirt bottle full of water, ideally you want no moisture left when the weld is cool, (the heat of the weld evaporates all the water).
As to welder quality, please don't buy an ebay or Bunnings special, go to a welding supplier and test your chosen welder on material of bodywork thickness - who cares if a welder will lay a 10mm fillet in one pass, (which NO MIG will, FCAW maybe), control is what you want.
As to gas, if bodywork is your aim solely, then there are some argon mixes aimed at the body industry otherwise I would use good old CO2.

[Peter57]

Thanks KB and Karl,

I've been using a Magmate 180P with the argon/CO2 mix and it took a little while to achieve acceptable results. I think the wire may have been on the thicker side though.
I'm thinking about the Lincoln PowerMIG 180C right now. It's a little more expensive than the Magmate, but I know Lincoln have a good name. This particular unit is made in Italy so the guy at the welding shop informed me. Is it worth the extra $300 over the magmate? Anything else worth investigating?

I have the flanging tool already - it was one of the first things I bought. Very useful for sure. I'll try the conductive primer idea. So far the areas I have repaired are easy to access from the inside, so I plan to give them a good dose of cold gavlanising on the unexposed surface as well.

I contacted a welding specialist shop on Saturday and the guy there was incredibly helpful, I think I'll head out there next week and see if I can try the Lincoln. He did suggest an Kemmpi but at a little over $2k it'll never get past the CFO

thanks again for your help,

Peter

[Karl Robbers]

You're on the right track with either of those welders, the Migomag is also worth a look. The 180A capacity will handle anything the home user will attempt. Try them both on material similar to what you will work with and with the wire size you will use and you won't go wrong.

[KBs PensNmore]

In regards to gas, I would use a CO2/Argon mix as straight CO2 gives extra penetration and plenty of spatter, which on body work you won't need!!!!! Migomag is a reasonable welder also have had several of those over the years. What ever you get make sure parts and service are readily available.
Kryn

[Gringo]

Bronze mig wire is used a lot now for body repairs, for less distortion

It is expensive compared with steel, but might save you a lot of work

[Jarh73]

MIG 0.6mm wire
Decent quality MIG don't skimp too much.
I use ARGO SHIELD LIGHT.

With a decent MIG you will be up and running again in no time.

Cheers

Justin

[Peter57]

Thanks Guys,

I ended up buying a Powercraft 180i made by Lincoln (in China unfortunately). It seems like it will do what I want, has spares available, replaceable torch and came with a TIG torch as well so can have a go at TIG when I get time.

Now back to fixing the Krouty

cheers,
Peter