Need some tips on welding 22 ga. steel

I'm working on a new hood for my Marauder and will need to weld some 22 gauge pieces into the hood. I'm looking for any input on how to set up my PP256 to get the best results. I will have 4 types of joints. Butt welds, inside corner, outside corner and lap joints. In particular I'm wondering:
1) What size and type tungsten
2) What to use for filler material -- I've heard mig wire is good but I assume you would want uncoated?
3) Straight DC but how about using pulse? Any benifit?
Plus any other tips and tricks.
Attachment 10115
Attachment 10116
Attachment 10117

Quote:

---

Originally Posted by Ron66

I'm working on a new hood for my Marauder and will need to weld some 22 gauge pieces into the hood. I'm looking for any input on how to set up my PP256 to get the best results. I will have 4 types of joints. Butt welds, inside corner, outside corner and lap joints. In particular I'm wondering:
1) What size and type tungsten


2) What to use for filler material -- I've heard mig wire is good but I assume you would want uncoated?


3) Straight DC but how about using pulse? Any benifit?


Plus any other tips and tricks.
Attachment 10115
Attachment 10116
Attachment 10117

---

1) 1/16" or (worse case) 3/32" You want to keep the heat down.
2) ER-70s-6 1/16" or (.040) should be fine.
3) Pulse can help keep the heat down.

Also, you might want to check out weldingtipsandtircks.com search for TIG pulse welding. He might even have some car videos too. He does a lot of videos.

What Mike said. Practice on something first though. I'm welding some 18 gauge right now with MIG. While its not all that thin, I am doing it with .035...which does take a finer touch.

Thanks for the replies. I trolled the internet and there is quite a bit of info. I will definitely practice on some scrap.

I would do very small welds about every 3 inches, then come back and add another small weld. Repeat until finished the seams.
Some will say this leads to porosity in the welds, and that may occur, but you really don't need much strength in these welds anyway. If you try to weld them with long continuous beads you will likely not end up with a shape that you expect, and will probably need to fill in a few burn-through holes as well.

Just my 2 cents...I agree with small welds, but I would also try to use a backup strip (copper is best) any place you can...blocks, angle, flat stock, whatever you can get your hands on. Clamp it closely (and tightly) to the area which you are welding to help keep the material supported (and from buckling or warping). I have C-clamp vise grips with sections of tubing welded to lengthen the capacity. I use the C-clamps with the swivel pads so they don't dent the sheet metal.

I like to place tack welds about 3 inches apart, then split the difference and add tacks in between at 1" intervals (before I begin welding). Pulse would help if you are comfortable using it (I have yet to try pulse with tig, but I have welded sheet metal kitchen hoods and counter tops without it with pretty good success). Keep heat down and don't be afraid to quench the weld area with a cool (wet) rag as you go,should heat buildup become an issue. You'll probably find that the heat from welding causes the top (weld side) to "dip down", at which case you would want to apply the cool rag from the backside of the hood to draw the weld area "out." Otherwise, you'll end up with a dip all along the weld seam that will need to be hammered out and possibly heat shrunk (you don't want to go down that road!:O). Skip around, and work from the center out on the long flat surfaces, after everything is tacked together.

I like using MIG .035 wire (NOT flux-core that is stripped, just regular bare MIG wire) on mild steel sheet projects that are especially thin but you could use .040" or even 1/16" TIG rod as Mike pointed out (ER70S2 or ER70S6, whichever you have on hand). I usually like to go one round of stitch welds spaced throughout the workpiece, then grind the short welds down (almost smooth), hammer and dolly the areas that are high or low, and make another round of short welds (repeating this process) until it is finished. Some don't like to grind the welds until everything is finished, but I like to a lot of the time. Make sure you don't get undercut while welding either. Good penetration with just enough bead to grind off is what you want. I like using a needle-sharp tungsten here with smaller rod, producing a smaller bead overall.

There are many ways to skin a cat, so soak up all the info you can and make sure you're comfortable welding before you start on the real deal. The welding tips and tricks forum and Jody's videos would be an excellent source of information, as already mentioned. He comes up with a lot of ideas that I never would have! You might want to secure a brace (or 3) to the underside of the hood so that you can test fit it during the welding process too. Post pics of your work when done (WHAT? I like pics! Haha). ;)

Thanks for all of the tips. I was planning to tack weld it on the car with a welding blanket over the motor to make sure it will fit afterwards.

Progress is slow on my hood. I have a new problem. I'm welding in pieces that meet at a 45 degree angle and I cant seem to find a way to keep the weld from pulling the metal out of shape. Is this something I'll have to live with or is there a way to keep this from happening?

Attachment 10915

Attachment 10916

Attachment 10917

Fast quick short welds, you can use some magnets to hold the small pieces together when working on small stuff. I am getting ready to shave and bullnose a hood. It will be low heat and quick and a lot of moving around.

i have never welded on a car but i have welded (technically it's not welding) on some light gauge sheet when i had to keep the heat down. i used silicon bronze (everdur/sp?) i keep a pound of it , 1/16th on the truck but i have also run it through a spool gun, .035 dia., you can probably get it even thinner. cleans up nice and easy and goes down like butter on very low heat.

I've been using .030 mig wire. My problem doesn't seem to be heat. the discoloration is only about the diameter of a dime. It's the welds pulling on the metal.

That pulling is from heat. Just because the HAZ is small, it still causes the metal to shrink as it cools. That happens anytime you bring the metal up to melting temperature. By brazing you never get the metal to melting temp so you don't get that type of distortion. (You get a different type instead ;) ) But it is a lot easier to deal with. I hear that a lot of new cars require MIG brazing for repairs so as not to upset the heat treated high strength steels they are made from. Auto body welding is an art unto itself. All I can say is practice on scrap and try different techniques to learn what does what. TIG brazing can be very gentle as long as you remember you are not looking to melt the base metal.