OK, I have a fairly new Lincoln 175hd welder, it is 220volt I have have not done a ton of welding but enough to to be dumb I guess. what I have welded in the past is 1/4" thick metal like a totally fabbed snow plow mount for my ram truck. shortened and welded a steel flatbed(thinner metal for top , diamond plate) to same truck. various trailer repairs. and such.,,, so my new to me 914 needs a few welds like in the front trunk where the previous owner did as trunk patch. I start by filling in a couple of small screw holes, that goes fine, then I tried the seam and it seems like I am blowing right through the metal. or it keeps puddling like a drip below.? and forget trying to fill a small gap..... Now let me say I am using FLUX CORED WIRE. with no gas. (I haven't ever used gas) is that my problem? did I just get away with it in my thicker metal? I know a buddy told me flux-cored gets more penetration. this is the first "sheet metal" welding I have done. Any input is welcome.

I believe the flux cored wire is relatively heavy gauge and perhaps too heavy for butt welding body metal. Get a gas bottle and some thinner wire and have fun.

I'd try shorter welding cycles, maybe a lower power level and/or feed rate. FCAW is a PWM process so you set power via Voltage*current and current is bursts dependent on feed rate and the voltage.

Edit, to be more clear: Generally you set voltage with the knob or switches or whatever, and you control average current via feed rate 'cause you short the wire, it melts then no current flows, etc.

Incidentally, pet peeve, Flux core welding is generally not MIG, it's FCAW(Flux core arc welding). Hell, MIG isn't usually MIG it's GMAW (Gas metal arc welding) as the gas is generally Co2 and a small amount of argon (IIRC)

This is how puzzled I was... I looked at the manual,,, is is on the lowest power setting and the feed rate is 2.5-3 (which the manual suggested) , what is puzzling is that at a faster feed rate. (which I was at first) it seemed to eat away the metal faster ? seemed backwards to me. I was able to close a 1/4" bolt hole, but the the drip on the underside is like 1/2" long!!!I did this by welding a little then letting it cool (15 seconds) not red then hit it again for a second or two. and so on . has anyone had any success with flux cored wire?

The only flux cored wire I ever used was stick welding and I have used that for sheetmetal but it's not easy or pretty. You can try putting a piece of copper behind what you are welding and it will be smooth on the back.

If you read my post the amount of energy you put in is proportional to feed rate and voltage setting. I'd suggest dropping the feed rate and welding in bursts. I'm not sure about the effect of using thinner wire, but I think it might work better.

Edit: Some of the most fun I had welding was with FCAW and a shielding gas, Spray welding is bitchin'.

I only know welding with my MIG.... Not too much exoerience, but just replaced the rear trunk pan and fabed some replacement panels out of 20 gauge sheet from Home Depot. I found the following to be true.

1. Power on lowest setting.
2. Using a heavy extension cord to even reduce the amps more. Small one - 5 feet, but does the job.
3. Wire setting on 5 as a feed rate.
4. When it POP, POP, POP's, doing it wrong. Leaned the 'gun' over on a more severe angle and got a steady sizzle sound.
5. Butt welded several pieces using a zig-zag motion with feed at 5. Filled gap with nice pool.

Now I am tackling the inner floor boards. Not afraid anymore. Burn-through came when I was too slow on the zig-zag.

my 2 cents...

I did this with a flux core welder, i pretty much had the settings at a medium feed speed and low power setting. Then i tack welded the piece onto the car and then connected the tack welds with more tack welds and then ground the tack welds down.

It will make things MUCH easier for you, and you'll have less spatter, too. Make sure you also get the correct corresponding tip for the welding gun. It's different than the one you use with flux core wire.

You're in Indianapolis, and I'm sure you can find a welding supplier somewhere there that can set you up with a tank. Why make more work for yourself than necessary?

I did my entire care with flux core as I could not find somone selling gas, and I had a lot of flux cored wire. I was using a 120V 15 amp welder, so not as much power as yours. Welding thick metal is EASIER then thin metal.

Use a copper backer (like a mashed flat piece of copper pipe) behind your weld. It will act like a heat sink, and will help prevent blow through. Hold it in place with either clamps or a strong welding magnate. Weld does not stick to copper.

Where possible, use lap welds. Thicker metal, easier welds.

Don't try to weld continous beads. Just make lots of tack welds, maybe an inch apart. Then make more. then make more, until your seam is welded shut. This keeps the metal from over heating.

I don't like the extension cord idea, though I hear it all the time.
Good luck.

Zach

Get the shielding gas kit for that welder, and use 023 wire. You won't believe the difference.

Welding thin metal with that size flux core wire is all about technique and practice. I can be done, but you'll have more blow throughs.

The jist is yes you can learn to "get by" with flux core wire as I got by with stick at first because sheetmetal was not the norm at my place. Once sheetmetal became the most welding I was doing I added a mig. Now I have added a tig mainly for the aluminum and ss fabbing. It depends on how hardheaded or money conscious you want to be and what you want the finished product to look like. John Kelly uses only a torch on body panels I think and he does great work. I have also used a torch but I don't like the heat it puts in the surrounding area it takes a lot longer to melt the metal with a torch versus a electric arc. I can only go about 1/2 inch butt welding with a torch and with the mig it is 1.0 inch. If you are interested check out the real small torches a lot of guys use for torch welding. I think they are the best way to go with gas welding.

The type of filler rod or wire also makes a big difference on the final outcome of welds. ie how much hammering the weld will take and how different the alloy is from the sheetmetal you are using.