im looking to do some rust hole patching on my car and i have some experience with oxy/act. welding but i dont know what the difference is really between ARC and MIG welding...?

can any explain this to me and which is better for patching up small holes in the body of the car?

 

Arc welding (stickwelding) can't be done on sheet metal.

 

ARC is for heavy duty, thick medal welding, and as 67t5ponycoupe stated, don’t try it on sheet medal. It will only melt holes in your sheet medal. MIG (or wire feed) welding is wonderful for all thicknesses of medal. From thick to thin, and if you use the optional gas (like Argon) attachment, it makes a very clean weld with no slag! MIG is suited for a novice welder or beginner, but not an ARC; it’s messy and harder to be good at.

Cheers.....[sm=icon_cheers.gif]

 

some more food for thought.

I was actually two seconds away from paying for $175 worth of Bottles w/gas, regulator and other welding supplies today, then the dude working asked me what I was doing. I tell you what, its sure is nice to find some honest, helpful and very friendly people out there.

Luckily the guy said if my welder was a dual mig welder, which just so happened to be, I should just think about flux cored welding. I had thought this over, but b/c it’s a lot messier I threw out that idea, thinking that the gas shielding would be a much better weld. He said the strength of the welds aren't going to be any different, this I don’t know.

But, at least he got me thinking, if im going to be doing a lot of tack welding pieces of sheet metal that will be all hidden from view. Is it necessary to have solid welds that only
"look" to be done by a professional. And at least my welder came with a spool of flux core, so why not give it a try on some spare metal first and see if I like. And a flux cored mig welder is really cheap.

Hopefully we'll here from the experienced experimenters on which is more cost effective and some pros and cons of each.

 

Give it a try if you have it. I doubt you are going to like it. I've tied it and was never happy. It splatters like mad and looks like heck. Maybe you will have better luck. Welding with gas is the only way to go as far as I'm concerned.

 

I have used both on my stang. Actually it was the same wire feed unit, but we ran out of gas, and having to choose between beer and gas we of course choose the beer. I found the results were the same in the end after grinding; but it was much easlier to get the desired flow using the gas. I am by no means a professional welder, but have done my share. What it boils down to is your comfort level and knowing that in the end it's going to be ground down.

One piece of advice, with the arc welder I was taught to pull the bead towrd you, I found with the wire it was easlier to work away from you.

Hope it helps

 

Hmm...pushed the bead with wire huh? I always pulled it. Always woked for me but I'll try anything. Word of advice, if you are doing sheet metal, it is very temping to start running a continuous bead once you get the bead going. DON'T DO IT! Put a stitch (tack) in and move down a few inches and put another stitch in, and so on. Take breaks and allow the panel to cool. If you try to run continuously you will warp the panel. It won't happen every time but the first time you warp one you will be so dang pissed off. They usually don't warp little they warp big. Trust me on this one.

 

Another thing I just learned with flux core is keep the wire about an inch out of the tip, and if you want take off the shield. It allows the flux to gas, and really reduces the spatter.
I'd never welded with flux core before, and was really hating life. I screwed around all weekend trying to get something decent and gave up. When I went to the welding store to buy a bottle, the guy gave me that advice. Worked exceptionally well. Not as well as a pro machine that does spray arc, but still pretty well. The advantage to flux core is the ability to get consistent penetration even on dirty metal. Argon/CO2 welding does not tolerate dirty metal. You won't get penetration. Might look pretty sitting on top.

One more thing for anyone who has never done mig welding. You can lay down what looks like the most beautiful row of nickles (i.e. pretty weld) and not get a bit of penetration. This is where "stick" Arc welding is easier. You have to pay close attention and set your wire speed and amperage up correctly. Take some time and practice on different materials. When you can weld different thickness metals and get nice penetration on both sides, you are ready to rock and roll.

First welding class I ever took, the instructor basically said "...we can read books, or we can weld. Nothing is going to teach you to weld, except welding". We spent the entire semester welding. He'd walk over in the middle of a weld and grab your hand and guide it. Was a little unnerving at first, but by the end, I was doing some awesome things thanks to him. We still had to read the book...on our own time.

Good luck. Welding is a total blast!

 

if you have the skill TIG welding will produce the nicest welds which means they will be less of a bitch to clean up. MIG throws alot of buckshot that is hard to get off if you dont remove it quickly

 

dont weld with a fan next to u it blows the sheilding gas away!!!