Does anyone have any experience with welding the body sheet metal with a wire feed welder? (aka "gassless" MIG) The welder uses flux-core wire instead of solid and is essentially the same principle as a MIG but without the shielding gas since the flux-core provides the sheilding. I've got a Lincoln Pro 100 that can be converted to a true MIG with a kit but I wondered if anyone had experience putting on quarters or otherwise doing repairs on sheetmetal with flux-core. Most of my welds will be hidden either by the vinyl top or underneath weather stripping, so appearance isn't a factor. Thanks, -Phil
flux core is doable but will spatter more and the weld will be heavier. More grinding, more to hide. You said it was for hidden areas so it shouldn't be a problem. One point I should brind up. With flux core wire, limit the weld to no more than 1 second. FC heats up rather quickly.
Bill, I have an old Nova trunk lid taking up space in the back yard that's going to be my educational sample. I figure if necessary I'll go buy the MIG kit for the welder (it's $89 at Home Depot) and gas if the results aren't what I want. Thanks, -Phil
Phil Get the gas set-up and buy a quality 4" grinder. To do the job properly, you want to weld clean metal. You can clean the areas to be welded with a grinder or wire brush, apply some weld-thru primer and be set. Once done welding, you want to grind the weld smooth and primer right away or use phosphoric acid to prepare the bare metal. You can get the acid at Home Depot. Then, you will need quality filler such as DuraGlass and then sanding and primer. I have attached a pic of the acid from Home Depot.
Weld Thru Primer? I'm not familiar with that term. Does it mean that I can apply the stuff first (to protect the metal from rusting) and then "weld thru" it later without having to strip it off?
You are correct Dave. It is a zinc based product, prevents corrosion/rust, prevents splatter and does not affect weld integrity. I get it from my local Sherwin Williams Auto Paint Supply store. Check out your local stores for it.
One thing I learned is NEVER use a grinder or cutoff wheel to prep sheet metal for welding. The metal is thin to begin with and taking metal away makes for a lot of burn through. A wire wheel on a die grinder or drill works fine but always wear eye protection. Oh yeah and Phil, you need to stitch weld sheet metal. That means spot welds about an inch and a half apart along the joint. Then start at the beginning and spot between the spots. Repeat the process until the joint is complete. The idea behind this is the heat doesn't build up in any one area. If you run a bead, the metal will get too hot and warp like crazy.
Reason I stated a grinder is to get to good metal. Sometimes, you can see the body panel/area has rust throughout and will need to make your cut higher. You don't want to weld to rusty metal or thin metal, you will blow/burn right thru it. Grinder is to be used as a sample metal inspection tool only. Sorry if that was not clear.
