Welding. Flux core and argon

Ok, so I have limited welding experience. I welded some when I built a turbo kit for my Mustang, but it was all pretty thick pipe. I welded the pipe fine using flux core, but when I tried to fill some holes in the engine compartment sheet metal, it was trying to blow through it even with the voltage all the way down. I was wondering if thin sheet metal is any easier to weld with thiner wire and argon. The mig is a Millermatic(not sure what series) set up for gas, and the inside of the door says you can weld 18ga steel with it.

Thanks,

AC

 

Most sheet metal used in body panels is 18 and 20 Gauge. Gas welding does work better on thinner metal. Its a mix of 75% argon and 25% Co2. Even with gas, it takes some practice to weld the thinner metals.

 

Well thats good to hear. I hope that those quarter panel replacements arent any thinnner than 18ga, as I plan on welding them in myself. Im practicing on the underhood hole filling and non-critcal stuff, and I plan to cut up an old hood and practice butt welding with the pieces. Thanks for the info.

AC

 

I am no welder either but dont you need to have a peice of copper behind the hole to use a mig. Just wondering.

 

Im not sure. I was just doing it the way Ive watched my dad do it in the past. He fills holes with no backing most of the time. If its larger than say, 1/4" he sticks a stick welding rod in there to fill in some of the gap... Maybe it would make it easier if I tried with a backing.

AC

 

For holes over 1/4 inch a piece of brass or copper would be helpful. Also if those are rust holes you are fixing the metal will be alot thinner in that area. Try building up around the hole before filling the hole. I've only welded with MIG/GAS so not sure how Flux Core wire works.

 

Well, the front clip is off of a donor Comet because I wrecked the car when I was 16. I drilled all the spot welds out of both cars and just transferred the new clip the the Mav. The spots I was trying to fill are a little thin as there was a little bit of rust on the replacement clip. Im sure that was making things tougher on me. Im going to get the bottle filled next week I hope. I guess we will see what, if any, improvement that makes. I also need to start using the gas anyways, as flux core is nasty stuff. It leaves all sorts of nasty slag and crud on the bead that has to be wirebrushed off. Kinda like stick. Me and dad just decided to try the flux core because we ran out of gas one weekend.

AC

 

Using the 75/25 mix gas in your Miller will let you weld thin stuff. I think you actually get a more controlled weld and you have to less work prior to paint - no flux to clean off. You will still need practice.
Using a flux core, on a wire feed, is kind of, sort of like having a never ending welding rod on a stick welder. I also like using a stick welder for thin stuff. It's all about amperage and the type and thickness of the rod.

 

Great! Thanks Hawko et al. I cant wait to get some gas and start playing I really need to practice so I can fix my doors and quarters. I hope that before the new year Ill have them done.

AC

 

try oxy-acetylene welding...works great for sheetmetal....if you can get the hang of it that is........

 

Sounds cool Fearmont. I swear it seems like that would be tough to master. Isnt it difficult to keep from warping panels? I would like to see some pics of this and get more information. Also, is it as strong as a mig weld? To be honest, Ill probably stick with mig as its already here and set up, but torch welding does sound pretty interesting.

Thanks,

AC

 

My friend can do it....I want to learn how for the hell of it,kool skill to learn.I can stick weld,and of course mig/fluxcore.

 

I'd have to disagree with you on this one. I'm not saying it cant be done, but it puts way too much heat and in a larger area than a mig will. I'd say your probably ten times more likely to warp your panel. Plus with the torch, you have to add your filler material. For the mig, just pull the trigger for a split second, then move over to a cool place on the panel and hit it again.

 

I learned the oxy-acetyline way, I guess you could say I mastered it.
I never warped a panel and really loved doing it. Gave it all up when I
discovered mig welding. Mig is the way to go.
Dan

 

never said that its the only choice,I said it works great only if you can get the hang of doing it....definately not a technique you want to just try out for the first time on your car.