What The Hell Am I Doing Wrong?!

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I am SOOO mad....I've been trying to teach myself to weld for almost 2 years now, and all my welds look like crap.I've got a Lincoln Electric Weldpak HD. I guess it's one of the less expensive ones, basically it's a 120 Volt, 70 AMP Mig welder with the flux-core .035 welding line. If that description didn't explain it, this welder doesn't use gas.Anyway, I am repairing some rusted out sections of the sheet metal in my trunk floor of my 81 TransAm. For SOME reason, no matter what I do... all I manage to do is blow huge holes in the sheet metal with my welder. I'm not sure WHY. I've turned down the temperature / amperage to the lowest setting (which I guess is 20?) and it STILL burns holes through the sheet metal.I only pull the trigger for maybe 1 to 1.5 seconds, and when I look.. BAM, there's a hole. I guess I'm obviously doing it wrong...You know, I always think that I can just do anything and everything, but I can definitely tell that welding is not just a simple task like laying bricks or cutting carpet, or anything else like this. Welding to me (this has become real obvious) is a really difficult skill to learn. Anyway... anyone have any ideas, suggestions that might help?I'd really appreciate it... I'm butchering my 81 TransAm.   Thanks...Todd,2006 Pontiac Solstice2002 Ford Crown Victoria LX1997 Pontiac Grand Am GT1987 Pontiac Fiero SE / V6 5-Speed1987 Pontiac Fiero SE / V6 Auto1984 Pontiac Fiero 2m4 SE WS61981 Pontiac TransAm WS61973 Volkswagen Type-2 Transporter
Reply:If you're going to MIG (or in your case FCAW, the gasless equivalent) sheet metal with that sort of machine you'll probably want to do repetitive tacking rather than trying to run a longer bead.  My first welder was a Lincoln Handy-Core (basically the same thing you're using) with only 4 heat settings - Low-1, Low-2, High-1, High-2.  The WFS was infinitely controllable, but the amperage was in 4 large steps - useless for continuous welding on thin sheet.Turn down your WFS (wire feed speed, if the term isn't familiar to you) and turn UP the amperage to something like High-1.  Hit the sheet with many small tacks, one after the other and not lasting more than 1 second of trigger time.  Should get you part of the way there.It'll take some grinding, but with FCAW I think tack-move-tack-move will be the only way you'll get your thin sheet work done.MR
Reply:82-TA, welome to the club!   Welding rusty sheet metal is an impossible dream, even for the best of weldors.Using flux-core just stacks the odds against you. If you have access to hard wire in .030 or smaller you would have a better chance. The technique described by Mr. Blowin Breakers is exactly what you need to do, except go faster! 1/4 sec. tacks might work. Dont wait to recognize a puddle, just quick zap and off. If you try to look for a recognizable puddle, your already too late!......Maybe you should consider a lot of good tacks and then some bondo?  just my .02.......
Reply:Could be there's not much left of your floor to weld to. If so it could explain your bad case of the burn throughs. There's still one other trick you can try to reduce the heat on the weld area. Take a welding rod, knock the flux off it, hold it so the tip is where you want weld and blast the rod end with your mig gun. The thicker rod will take the brunt of the heat and deposit metal where you want it.  The trick is to knock a little off the end of the rod rather than let the whole thing stick. You could pull the rusted out area apart tugging if you let it freeze. That trick is also handy for filling giant gaps in a hurry.
Reply:I am in the process of installing patch panels.  I am using .023 solid wire and ocassianally burn through.  You have to stitch weld and have lots of patience to keep from burning a hole in your metal. How thick is your metal.  Some of the older rigs that are thick can be welded with bigger wire versus the newer thin stuff.  Sounds like your wire size may be to big.
Reply:Howdy!  there is another trick.  IF at all possible.  I am assuming, that this metal is not perfectly flat...?  If, you have flat sheet metal, you can put backing behind your sheetmetal.  THere are 2 kinds to use.  Consumeable, and non consumable.  The non consumeable would be for instance a copper bar that absorbs much of the excess heat, and the weld puddle won't stick to it ifyou have moderate burnthrough. It prevents holes, then you move the copper piece to the next area to be welded.  The other one, a consumeable backing, is probably more what would fit for ya.  shape some mild steel 16 guage or something to fit behind your finished surfaces.  Then weld with the plate behind your pieces, and it just stays in place after the fact, but it also can prevent burn through.  There is no pretty way to weld these thin rusty sheets with a flux core rig.  But you can get it structural again   I have also seen great results with rivets, and brazing.  Good luck!  I have an IH Scout II with much rust on it, and luckily for me, everythime I fix it, it just gets lighter   Nice thing about frame rails!  Most of the structural is with the rails. Good Luck  Brian Lee  Sparkeee24
Reply:I'm just a novice too, but an older gentleman once showed me to take about a two foot piece of 12 gauge bare copper wire, clamp it to your work, then clamp your ground clamp to the other end of that wire.  Seems to help me weld light stuff with my stick welder.  Just something you might try.  I think small tacks are you best bet.  Isn't that how they build new cars?  Good luck.  Sounds like you've got quite a collection of cars.
Reply:Thanks guys, I want to thank everyone for the advice....Well... a couple of things I've noticed.I really took all of your advices when I went back just a couple of minutes ago in my garage. Earlier today, I wanted to put an honest effort into this project (81 TransAm) and I hate, I absolutely HATE giving up. I went to home depot, and I bought a few things which have also helped me.Ok, this may sound REALLY dumb, so please excuse me for my ignorance. Was I supposed to be able to see through the shield? I never could, so I never quite bothered. So, I went to Home Depot, I bought some more anti splatter spray, I bought a face shield that goes on your head (the one I had before you were supposed to hold in your hands). I also bought a pair of welders gloves. Incidentally, everything I bought was from Lincoln Electric... I can't believe how much easier it is. I did what all of you guys said.. quick bursts. And with the face shield down, I can actually SEE the metal pooling up. What I was doing was like what you guys suggested. Quick bursts. Occasionally when I've got a really good pool going, I'll just keep the trigger pulled. I have some pitting in some places, and I'm trying to fill in the pits after I grind them out. (like filling cavities I suppose).On the thin sheet metal, like you guys said, I found that quick bursts of a half-second to one second seems to work perfectly. I also got some huge C-clamps to hold the sheet metal in place as well. Everything works SOOO much better.Thanks guys... I appreciate it.JerryMat, I actually got most of my cars for real cheap. The 73 VW Bus I got for $1,200 bucks with a new engine, new transmission, and a brand new paint job. It's a hobbyist's dream... all I had to do was buy everything else and just put it together. The 81 TransAm I got for dirt cheap, and I'm teaching myself how to weld by working on it. The 87 Fiero Auto was my first car... I bought it in high school with the money I made from Comp USA. The other Fieros I got pretty inexpensively. My 97 GrandAm is for sale (can't wait to get rid of it), and the Solstice should be coming in any day now... it will be my first new car. The 2002 Crown Vic.. regretably I got from my grandfather who passed away, but I know he'd want nothing more than someone like me to take care of it...Thanks guys, I really appreciate it. I'm going to hang around on this web site and hope I can pick up more experience from you guys.Thanks!!!Todd,2006 Pontiac Solstice2002 Ford Crown Victoria LX1997 Pontiac Grand Am GT1987 Pontiac Fiero SE / V6 5-Speed1987 Pontiac Fiero SE / V6 Auto1984 Pontiac Fiero 2m4 SE WS61981 Pontiac TransAm WS61973 Volkswagen Type-2 Transporter
Reply:Oh! Quick question... now that I've got a buildup of metal in some places... what do you guys recommend is the EASIEST, or I suppose.. most efficient way of grinding down the welds? I have a 4.5" angle grinder, is that the best tool to use?Thanks!!!!!!!!!!!Todd,2006 Pontiac Solstice2002 Ford Crown Victoria LX1997 Pontiac Grand Am GT1987 Pontiac Fiero SE / V6 5-Speed1987 Pontiac Fiero SE / V6 Auto1984 Pontiac Fiero 2m4 SE WS61981 Pontiac TransAm WS61973 Volkswagen Type-2 Transporter
Reply:82 T/A - GREAT news!  Nice to see my advice actually work for someone for once...   Regarding the metal removal, I would get a series of progressively more coarse flap wheels - something like 60 grit, 80g, 120g and grind 'er down.  The 120 will be great for blending into the existing metal, and the 60 will really make hay on larger clumps.  I have a 4.5" angle grinder and this is how I used to grind a lot of my FCAW welds.  Of course now I spoiled myself with a TIG setup so I can just dance with the pedal and save a lot of grinding later... but believe me, I think by the time you get really good with that FCAW rig you and I will have probably chewed some of the same dirt - I'm telling you that the flap wheels worked wonders for me, and hope they'll do the same for you.MR
Reply:82 TAI work on a lot of old cars, and welding old rusty sheet metal is a learned art. Your on the right track, and have gotten some good advice from the other members. I have learned a way to do it that works very well for me. But first, the seeing thing. Get a #9 lens. If you have a #10 or an automatic non adjustable helment, I have found that smaller machines don't put off enough light for a #10 lens. It helps a lot. I have developed this way of starting a puddle, pausing, letting it cool just a bit, then move back to the middle of the puddle and do another circular weld, stop let it cool etc. I never let it get so cool I can't see the glow thru your lens. It is like a half step back, and a half a weld forward. I wish I was better with words. It is kinda a rhythm thing, but when you get it, you can produce some good looking welds on old crapy steel. We are going to have to get you off these Pontiac's and on to some Mopars...<;-)
Reply:don't pull.. push and go fast.. that's all
Reply:I wouldn't suggest pushing the weld since it is flux core you are welding with.
Reply:pushing doesn't penetrate as much as pulling.. therefore you won't burn through as easy
Reply:I agree about the penetration being less with pushing instead of pulling when using solid wire. I have always thought though with flux core wire you should drag it to keep from entrapping slag.
Reply:Whatever works gnewby, whatever it takes, just get er done. You should drag  core wire but there are times when it works to push.
Reply:I've tried dragging it, and pushing it, with the 035 flux core wire.   I actually got better welds pushing.  Just like you would with gas and solid wire.  I got a lot of "Air bubbles" in the weld when I tried dragging it.  I also found that I was usually moving too fast (On thicker metal)      I once welded the oil pan on my 79 bronco.  It had been sitting for a few years, and the grass grew up around the oil pan, and rusted it out.  I did not realize it was as bad as it was until after I blew the motor.  Funny part was, I blew the motor trying to fix the oil leak. (about a quart a week)     I used a stainless wire wheel on my grinder to buff the side of the oil pan clean.  I found a hole in the side of the pan after buffing.  I stuck a screw in the hole with some silicone gasket material on it.  About 2 weeks later I was driving to work and all of a sudden.... boom     a couple of back fires out the carb. and that was that.      Coasted to a side road and tried to restart it.  No luck.  Turned out when I pulled it apart. I found a piece of stainless steel wire stuck in the oil pump.  yup sucked that wire right up through the sump.         When I pulled the pan I found that it was rusted really bad, and It was $400 + to get a new oil pan.  I molded a piece of sheet metal. 18 gauge to the outside of the pan and used a friends MIG to weld it on. (.030 gas, miller 135) I chased those rust holes half way across the pan before I found some solid metal to weld to.  I then ended up welding all the way back to the plate, (didn't have a big enough piece of plate)  using short bursts and welding to the weld.  Being able to see was really important. because as the bead cooled, as soon as it was out of sight through the lens. I would squeeze out another burst.  took forever....and I made sure I cleaned all the little pieces of wire out of the inside of the pan before reinstalling it.  You know.... that bronco stopped going through a liter of oil a week after that.  And a far as I know. that pan is still on, and it's still running.  I always thought the major oil consumption was the rings.  But it was the pan most of the time.  OH ya.  When the oil pump seized.  it blew the cam shaft gear right apart.Lincoln 225 AC/DC, Hobart 140 Mig. Oxy/propane Victor torch.(2) Makita 5" angle grinders  one with zip disk, 14" chop saw.  and just about every other tool you can think of. Whoever has the most toys when he die's ..... Wins!