Welding Tips and Tricks

Ok guys,
I am lower than a beginner welder and have a question I can't seem to get googled. I got my hands on a Vulcan 170 from harbor freight. I am restoring a classic mini and replacing some panels. The majority of my welds are plug welds but have some panels patches to weld in that will be covered and aren't structural.
I am about to deploy for 6 months so I haven't messed around with gas mig. Just the flux core. The penetration was decent but not perfect.
My question is could I just rust a weld on both sides of the panel grind them down a little put some seem sealer on and call it a day? Or is welding on both sides of something like 16g or 18g a no no.

I have no idea thanks for any information.

Plug welds can be hard at first with mig till you get the machine dialed in. Welding both sides will work just run some practice beads to figure out how much burn through you will get. If your just going to sand it down for looks with some body putty I’m guessing it will be fine.

Ok I think my biggest concern. Would be does welding both sides on something thin mess it up. But I guess I'm only working about blowing through or warping

human89 wrote:Ok I think my biggest concern. Would be does welding both sides on something thin mess it up. But I guess I'm only working about blowing through or warping

warpage would be the main concern. last thing you want to be doing is adding any more heat or shrinkage.
i think gasless fluxcore on car panels the usual problem is blowing through not lack of penetration.
personally i would use gas and weld only one side.

You do NOT want to use Fluxcore to weld body panels for all the reasons Tweake mentioned.

Get the thinnest ER70-S6 wire your machine will run (maybe 0.024) and some MIG gas 75/25. Clean the panel to bright shiny metal, absolutely no rust on either side. Spot tack the joint only. You need a tight fit. If you have a gap, arc on one side or the other, not the gap. Move around allowing the panel to cool.

Tack, move, tack, move, tack, move. You can keep a bucket of chilled water handy, dish rag in it, plop the rag onto the panel periodically to chill the absorbed heat. Dry, and tack, move, tack, move.

This takes hours to do. It can nearly eliminate any warpage, but you must have the patience of Job. Any impatience will cause blow-outs and rippled panels.

And keep your CWD (contact-work-distance) tight. That's the distance of wire to metal when you pull the trigger. About 3/16" is what I use when panel stitching. Damn, it takes forever to do those panels

Don't you mean "CTWD"?