welding sheet metal - question Options

[njccmd2002]

first of all let me clarify, my welding skills are the same as me flying the space shuttle.

Although im not stupid...

First of all ill star by saying that im using a crappy harbor freight mig welder....

Yes i know.

My question is why when i weld sheet metal, when the borders are clean of rust, and good separation between sheets, the welder melts and makes holes.

I have it in the min setting and slowest speed.

The only way i found i can do it is by creating a mountain of slag, which is a pain to go back and grind.

for example....

i have grinded the bottom here...



here is a closeup...




and here is the back...




I know im not an expert, but this welder sucks ass.. Period, no good settings, all good to make sparkle, but it welds like crap.

What should i do...

A. Should I go for a TIG welder...

B. Or a better mig, i mean, are all migs going to give me this crappy buildup...


I HATE GRINDING......

please advise...

[playr158]

Flux or gas?

What thickness wire are you using.

[FallenHero]

looks like low energy flux core. Can you get it on a higher setting? How thick was the gap? Also, you might have had the tip too far away from the metal, causing it to sputter out giving the look we can see.

[presure2]

lots of problems there, berto.

welding thin sheet metal with flux core is tough, it burns hot, and has a tendancy to just burn thru.
got any pics of the gun?
make sure the tip sticks out of the cup about 1/16th or an 1/8, and keep your wire stick out to ~1/2" or so.
gun angle is important too.

check out www.weldingtipsandtricks.com , watch some of the mig welding vids, they were a huge help to me. (i pretty much learned to tig weld by reading and watching his vids.)

[al94st]

Yea welding with a flux core mig on thin metal is super annoying. I did all my intercooler and exhaust piping that way. I actually went back and double check/touched up the IC piping last night. Flux core is going to have a lot of slag like that, there's no way around it. Your angle grinder will be your new girlfriend. Just take your time (do a bit and if you get annoyed walk away and come back later) and it'll come out OK with some practice. Oh, and make sure you prep the metal really well first and have a really good ground.

[njccmd2002]

yeah, flux core. the cheap harbor freight one.

I tried different approaches and nothing,

Tried tacking, tried running fast, slow, its just too damn hot and melts like butter. I have a good ground, the metal is stripped out of pait.. it has weldable primer, which helps reduce the splatter to stick..

Now i weld for an hour and grind for 2.

So what i will do is finish this section, and then buy a new welder, time to upgrade.

[Bitter]

TIG /thread.

[stephen_lee]

or jump for the high end mig there. use GAS and use .023 wire.

i've welded 16ga fine using .030 flux with the 160a harbor freight mig

[epocsirhc]

I'm a big tig welding fan, but even I would use a mig welder in your situation. At home I use a 220V Miller, and I've done exhausts, new floor pans, Subaru crank pulley holders, etc.

The learning curve on a tig welder is very steep compared to mig imo. Also you have to figure the cost to purchase and operate the machine. How would you weld in that situation with your filler rod in one hand, torch in the other and modulate the foot pedal or run on lift arc.