80a/90a FCAW and sheet metal

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Hi everyone,Getting started in welding with a Harbor Freight 90 amp flux-core welder. This welder has only two settings - 80 amps ('low') and 90 amps ('high'). I find that low works fine for exhaust pipe. I had a scrap piece of pipe which I cut and welded back together several times. The high setting would cause burn through. I was using a low to medium wire speed practicing with the exhaust pipe.Ultimately I'd like to be able to do some autobody panel work. I have a few cars that need rocker panel repairs. Whenever I've tried using the low/80a setting with the lowest wire speed, I still seem to burn through sheet metal. I tried practicing with some tuna cans over the weekend and it was cutting holes through them like a plasma cutter.Is the burn-through a problem with my technique, or is the machine just too powerful at the low/80a setting? I'm using .035" flux-cored wire. I plan to upgrade to something better within the next month or so, but I'm just curious if this can be made to work with thinner metals.Thanks.
Reply:Fc wire is a hot process and a poor choice for thin sheet metal in general. Couple that with a machine with almost no heat control and you are really trying to make like as difficult as possible for yourself.Your best bet is to get a decent machine with at least several taps for heat control or better yet a unit with an infinite heat adjustment and run 75/25 gas and .023 solid wire. This will allow you do do thinner material than FC will. You still won't be able to run long continuous beads on really thin steel, but you can weld things up using a stitch method if nothing else.Last edited by DSW; 06-04-2012 at 09:56 PM..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Thanks for the reply.Like I said, I was just curious about this thing. I know it is probably one of the cheapest made welders on the market. I figure if I can weld anything with this thing, I will be off to a great start once I get a real MIG setup. It's a winner for exhaust pipe - it seems to handle that just fine, although I'm still a bit sloppy on the welds.Right now I'm leaning toward the Lincoln 180 tapped models (Pro Mig/HD). I want 220v so I can work with thicker structural repairs as well as thin sheet metal. I was looking at the Power Mig/C (continuous adjustable) models but it looks like they are $200 more and I can just play with the feed speed to make the tapped version work just as well.