welding sheet metal

[projectAtoB]

I am about to dive into a lowered street truck and i want to shave everything. Im am by no means a great welder but i do ok with thick steel. But holy crap i need some pointers on welding sheet metal. I have a 220 hobart mig welder with gas at my dads, but i bought a 110 welder that is strictly gasless welding. i bought this for the sole purpose of tacking big parts at my house and welding them at my dads and to weld sheet metal. well i have been practicing on sheet metal with it...... and i suck at it!!!. I need some pointers. i dont have money to buy a tig welder or another welder at all for that matter. please any help would be great. the welder i have has a high low voltage setting and a wire speed setting of 1-10 i really hope you guys can help me.

 

[Crazythingsido2]

set it low probable not higher that 4 for sheet metal AND TAKE YOUR TIME if you rush this your going to warp the hell out of everything

 

[projectAtoB]

i having more problems with it burning through.

 

[marcehboy]

Tack it across in different spots each time till it gets completely filled in and as said before TAKE YOUR TIME you will warp it.

 

[83bagged]

tacks man tacks

tack once every 4 - 6 inches. depending on how thick the metal is and how hot your machine is. its best to have a 110 machine for this, i have a hobart 187(220) and i set mine on

heat 2 and speed 30

 

[Crazythingsido2]

if your burning throught you heat is too high turn down the heat and turn up your wire speed and just tack like every 3 or so inches

 

[COPPERHEAD85]

if you can get behind it use a piece of alum.
weld wont stick to it.
sorry.......flux core stinks for this kinda stuff.

 

[Ranger#1]

turn the heat all the way down and go from there wire speed id go around 2.5 to 3.5 also what machiene do you have

 

[projectAtoB]

ive been asking around other places and have got about the same advice. along with flux core sucks for sheet metal. the welder is just a cheap one from harbor freight. no name brand. the one at my dads is a nice hobart one. i just got this at a good deal from someone who was hard up for cash, only paid 40 bucks for it and it was brand new. i will def. try the aluminum trick that is a new one i havent heard of. thanks for all of your help and if anyone else has something to add please do i need all the help i can get.

 

[Destroyer000]

if you can get behind it i like to used a piece of copper.

 

[BlackBII]

The aluminum trick sometimes helps, and, make sure you are 'pushing' the puddle and not pulling it. You don't have to tak sheet metal....I was welder for quite a while, welding a lot of sheet metal. My welders were always cranked to the max, you just gotta learn to move fast.

 

[turbo cat]

you really cant do that great of a job with flux core on sheet metal

 

[Loanranger]

First thing, keep everything clean. Strip any paint, rust, etc away from the area to be welded.
The fluxcore welder is going to suck to use, it isn't made for high quality welds. You would be much better with the 220 welder with gas. Set it on 1 or 2 for the heat setting, and between 3-5 for wire speed, higher heat, higher wire speed, lower heat, lower wire speed.

The key is to tack weld. Keep the heat down on the panel as much as possible. DO NOT try to weld the seam in one pass, you will end up with very bad warpage. The more evenly you distribute your tacks, the more evenly it will pull the panel, resulting in less warpage. This is one thing to remember. Any welding you do on sheetmetal is going to shrink the panel, the more heat, the more shrinkage. So this also means the more consistantly you heat affect the panel, the less it will warp. If you have a bunch of differently penetrating welds, IE hot welds, cold welds, all along a seam, each of those tacks is going to pull on the panel at different rates.

If you're burning through, there could be a couple reasons. Either you are running too hot, not enough wire speed, or the gap you're trying to weld is too wide. If I'm making belt cuts, say in the sail panel of a quarter panel, I overlap the two pieces, making sure to line everything up right (gaps...) and then cut through both pieces with a 32t airsaw blade. This leaves just enough gap to make a nice weld that will penetrate no matter what, and you can grind it flush without worry of cracking.

Sheetmetal is an evil demon, but if you take your time to learn what to expect, you'll get it down in no time. You really, really, really should use the gas welder though, it'll make your life so much easier.

And the only time you should need a weld backer of aluminum or copper (copper works the best) is if the sheetmetal is deteriorated by rust, or ground or stretched thin.

 

[woodyedmiston]

What loanranger said about cleaning the area of the weld. Get rid of the paint, it contaminates the weld, makes it heat up, helps hold heat in the area. Dont get hung up on welding the pieces in one pass. Just spot weld in alternate areas - think of placement sort of like torquing a head until you have closed the seam.

There are some good internet sites that will tell you how to use heat and hammers to shrink the metal and form it.

 

[ZMan]

The aluminum trick sometimes helps, and, make sure you are 'pushing' the puddle and not pulling it. You don't have to tak sheet metal....I was welder for quite a while, welding a lot of sheet metal. My welders were always cranked to the max, you just gotta learn to move fast.

ehh its a personal preference thing when it comes to pushing/pulling. Personally I can't push sheet metal.