Which welder to get for welding sheet metal? MIG or TIG?

[Proud_Hillbilly]

I am thinking of doing some light repairs on my old Ford truck.. The rust got the best of it with time..

So I would like to repair some of the rusted areas. Its a truck I use around the farm but I am starting to get a bit worried considering the amount of rust all over everywhere. I don't mind the rust itself but what if I fall through the floor while driving around the farm lol.

So I would like to try and repair it myself. I am not a welder and I don't really know much about it but I guess everyone can learn. Right?

Now the question is should I get the MIG or TIG in order to do sheet metal?
I read that the TIG will provide cleaner results but I am really not sure about the necessity of cleaner results.. Its an old busted up rusty truck so it doesn't really need to be clean so I am thinking of getting a MIG welder to do the job.

Is there anything else I am missing? Is there perhaps a reason to still go with the TIG?

If not which MIG would you recommend?

Also, I don't know how to weld so I will have to learn first and I am not sure which is better for me. TIG looks more difficult but I kinda like it because I have steady hands and love doing things peacefully.. almost like ZEN peacefully. MIG on another hand seems way easier but it explodes, makes buzz noises, sends sparks and etc flying around.... It will break my aura of peace and tranquility while working.. I can deal with that but TIG just seems way more interesting.

I have also thought about the stick welding method but I think that will not work for auto repairs.

What do you think? Should I go with the TIG or MIG all things considered ?

 

[njneer]

Stick is too savage for thinner materials.
Mig by far the easiest to set up and use but needs good clean metal to weld properly , rust is a big problem for a mig welder for clean sound welds.
Tig is by far the most precise and best for thinner materials but a Tig welder is very difficult to set up properly and takes lots of practice to weld , it’s very similar in many ways to gas welding .
For a beginner a mig welder would be your best bet but you would need to cut back to good solid clean metal to weld it properly.
Get yourself a decent cheap Gas Mig welder ( avoid gassless welders) .
Get some new clean metals of various thickness and practice with temperature settings ( thicker the metal the higher the temperature)and wire speeds higher the temperature the quicker the wire speed) and get some feel for it before you start on the vehicle.

You want just enough heat to melt a puddle and enough wire speed to fill the puddle .
its a difficult thing to explain but when you get the temperature and wire speed right you can hear when it’s set right a nice steady crackle , no fits and starts no sticking or jumping.
If there are gaps between the crackles you need more wire speed, if the wire is pushing back Against the torch you need less speed.
Keep in a sheltered area wind will blow the gas away and you end up with welds full of aeriated bubble filled welds.
Also #1 rule a good helmet ,preferably and auto darkening one so you can keep both hands freee to steady yourself with new clean glass, when welding there is absolutely no substitute for seeing clearly when welding.

 

[Tractortech]

Now Then....
I'd also seriously consider a replacement truck!!
I assume this is a 4WD pickup type thing??
I've only ever done MIG with cars other than pre MIG and it was Oxy/Acetylene welding.
I welded new panels and patches in a Ford Cargo cab floor area, sills and patches on a Subaru pickup and some others with the gas. I've done a few cars with the MIG since I got it.
So, since gas is out of fashion nowadays and I've never done TIG, here are my thoughts.....
Rust or corrosion will be twice as much as you're expecting..
TIG welding is a 2 handed job, look carefully at where you'll be working,,, can you work on it with 2 hands comfortably??
Paint and more so, car body sealants oooze out from joints when heated and spoil any welding.
The metal is so thin & delicate, progress will be slow (TIG might be better here) as you'll make holes if too much heat and the rust from underneath a good looking panel will surprise you..
There'll be sparks, hot molten metal, dust and other such cack to deal with.
Welding has to be continuous around any repair for the MOT (quantity in case there's little quality type thing!!)..
Long term, a MIG will be more use and have more capable users than TIG (don't let the wire corrode or it's difficult to work with..
I set off to weld an exhaust hanger on the back of a Vauxhall Nova and finished up at the rear seats!! That was all MIG. The Cargo was all gas. Floor pan both sizes, structural members underneath, lower back wall full width!! I welded a sill on my own Cavalier after much cutting and drilling to get rid of the old corrosion...
So,,,, to sum up,,, and this is only my opinion,,,,, it's a horrible, horrible job...
Someone may be along shortly to put it in a better light.... ?

 

[Proud_Hillbilly]

Stick is too savage for thinner materials.
Mig by far the easiest to set up and use but needs good clean metal to weld properly , rust is a big problem for a mig welder for clean sound welds.
Tig is by far the most precise and best for thinner materials but a Tig welder is very difficult to set up properly and takes lots of practice to weld , it’s very similar in many ways to gas welding .
For a beginner a mig welder would be your best bet but you would need to cut back to good solid clean metal to weld it properly.
Get yourself a decent cheap Gas Mig welder ( avoid gassless welders) .
Get some new clean metals of various thickness and practice with temperature settings ( thicker the metal the higher the temperature)and wire speeds higher the temperature the quicker the wire speed) and get some feel for it before you start on the vehicle.

You want just enough heat to melt a puddle and enough wire speed to fill the puddle .
its a difficult thing to explain but when you get the temperature and wire speed right you can hear when it’s set right a nice steady crackle , no fits and starts no sticking or jumping.
If there are gaps between the crackles you need more wire speed, if the wire is pushing back Against the torch you need less speed.
Keep in a sheltered area wind will blow the gas away and you end up with welds full of aeriated bubble filled welds.
Also #1 rule a good helmet ,preferably and auto darkening one so you can keep both hands freee to steady yourself with new clean glass, when welding there is absolutely no substitute for seeing clearly when welding.

Thank you so much for such detailed input! Yes my thoughts were the same about the stick!

I didnt know that I should avoid the gasless type but I did have a hunch about it.. Thanks for letting me know.

The rust is the problem but if I clean it well would that help?

Now Then....
I'd also seriously consider a replacement truck!!
I assume this is a 4WD pickup type thing??
I've only ever done MIG with cars other than pre MIG and it was Oxy/Acetylene welding.
I welded new panels and patches in a Ford Cargo cab floor area, sills and patches on a Subaru pickup and some others with the gas. I've done a few cars with the MIG since I got it.
So, since gas is out of fashion nowadays and I've never done TIG, here are my thoughts.....
Rust or corrosion will be twice as much as you're expecting..
TIG welding is a 2 handed job, look carefully at where you'll be working,,, can you work on it with 2 hands comfortably??
Paint and more so, car body sealants oooze out from joints when heated and spoil any welding.
The metal is so thin & delicate, progress will be slow (TIG might be better here) as you'll make holes if too much heat and the rust from underneath a good looking panel will surprise you..
There'll be sparks, hot molten metal, dust and other such cack to deal with.
Welding has to be continuous around any repair for the MOT (quantity in case there's little quality type thing!!)..
Long term, a MIG will be more use and have more capable users than TIG (don't let the wire corrode or it's difficult to work with..
I set off to weld an exhaust hanger on the back of a Vauxhall Nova and finished up at the rear seats!! That was all MIG. The Cargo was all gas. Floor pan both sizes, structural members underneath, lower back wall full width!! I welded a sill on my own Cavalier after much cutting and drilling to get rid of the old corrosion...
So,,,, to sum up,,, and this is only my opinion,,,,, it's a horrible, horrible job...
Someone may be along shortly to put it in a better light.... ?

Yes its a pickup 4wd, old Ford I bought for pennies long time ago and fixed some engine problem. Its been serving me ever since on the farm.
Thank you for such a detailed input as well! I am now bought and will be going the MIG route!
My understanding is that the MIG wire is usually coated with something? Like copper? To avoid corrosion. Or am I wrong?
Also congrats on actually pulling the job off with your Vauxhall Nova. Just thinking about what I have to do with my car makes me appreciate when someone actually does it

 

[MrNoo]

Mig is much more forgiving especially if repairing floorpans etc where there will be rust, even if you cut it back to good steel, you will find some contamination and MIG will cope. TIG doesnt like dirt, oil, rust etc. It is a wonderful way to weld, very precise, satisfying. They are quite easy to set up and use. I use TIG on all my car stuff but MIG is just fine especially for someone new to welding a car up.
Mig wire does have a coating, looks like copper but not sure what it is, it will corrode eventually if left in a damp workshop.

 

[Kidds]

My understanding is that the MIG wire is usually coated with something? Like copper? To avoid corrosion. Or am I wrong?

Yes it is but here in the (usually) damp UK climate it can still be an issue. Just don't leave it sat in a damp shed for extended periods

 

[Tractortech]

Yes, MIG wire is copper coated. I left mine in the workshop for 12 months or so. Surface rust had developed and was a pig to weld with. I sprayed it with WD40 which seemed to help..
Cleaning paint and sealant off is crucial and yet another hideous job..

 

[335d]

With surface rust on the mig wire, wire wool Wrapped around the wire and a clothes peg before the feed rollers should help a bit

 

[dowcow]

I did up an old Japanese sports car once.... now those things rust. You don't just clean up the metal, you beat the crap out of it with a hammer and usually find a tiny little patch of rust is now much bigger than you expected. You have to cut rotten metal out completely as the welder will just make it pop and crumble and even if you manage to patch it, it will just keep rotting out again. Cut sections out and fabricate new sections. My old sports car ended up a certain % John Deere forager as we had one that was being broken and there were some decent sheets of steel available.

Seriously, a tiny hole in a crevice often needs several new chassis panels making, if your car body and chassis is made from spot welded thin plate steel as almost all are for the last 30 years or so it is a pain of a job. Not too bad if a labour of love, but cars requiring welding to pass inspection these days are usually a write off because it just isn't cost efficient. It might be easier with a pickup, certainly was easier with a Landrover as the steel is a bit thicker to begin with.

Make sure you keep some damp towels around too, as you can end up accidentally setting your car on fire where you don't expect it.

 

[pail of ale]

Clean steel is better but sometimes when welding up old bean tins ,cleaning to the desired level doesnt leave enough material to work with . Some mig wire will handle more rust and crap than others like ER70 S-6 or some of the fluxed wire . 0.8 mm solid wire or 0.9 flux . My welding is rough and ready but functional . I aint no pro .