Welding questions..

[Scaotty]

I have a ton of small holes all over my 75 280z now that ive removed all badges, molding strip, and rear window louvers. I have access to a gas welder (unsure of the exact type). What im wondering is what type of welder i need, and what procedure to take to fill these holes without warping the sheet metal of the car, or making any other kind of mistake. Any help would be appreciated, for i have no experience or knowledge in this field. Thank you.

[jmortensen]

Mig welder is the way to go. I would forget about trying to use an oxy/acetylene setup on a Datsun. The sheetmetal is so thin, I can't see how you could weld it without major warping.

[pwd]

Find a friend with a 110V MIG welder with gas attachment and that will be sufficient to fill sheet metal holes if you back them up with a copper spoon (available at Harbor Freight).

I've also used body solder with some copper foil as a backing backing metal. You can do this with a Propane torch and avoid warping metal.

[EScanlon]

Or you could do this with an old 100 watt soldering iron, some acid core solder and some tinning fluid. Heat the hole after putting a drop of tinning fluid into the hole, then just wick a tiny amount of solder into the hole. Once cool, sand it smooth and continue with your body work.

The MIG, oxy/acetylene and Propane will all heat the metal substantially and unless you're very good at working fast, there is a very good chance that you WILL warp the metal. It CAN be done with those tools, but it DOES require a good amount of experience with them.

The process I'm mentioning is an old body shop trick, that will rarely if ever warp the metal. The biggest caveat is having to neutralize the acid from the acid core solder. A simple wipe with either Wax and Grease remover or Lacquer Thinner and you're done.

FWIW

E

[240Z-Fan]

Or you could do this with an old 100 watt soldering iron, some acid core solder and some tinning fluid. Heat the hole after putting a drop of tinning fluid into the hole, then just wick a tiny amount of solder into the hole. Once cool, sand it smooth and continue with your body work.

[...]

E

Cool trick E!

Al

[timhypo]

WITH THE RIGHT TIP <- Key phrase there, a gas welder can be used on extremely thin metals without issue. I can weld an aluminum pop can together with my jeweler's torch that I couldn't touch with my MIG. An added bonus of using a gas-welder vs a MIG is that the metal is heated more slowly leaving less work-hardening and allowing you to hammer and dolly it easily when you're done. The most common way to do this nowadays is with a MIG, but I didn't wanna discount the gas torch. If you wanna try your hand, buy a 00 tip and practice on a spare body panel of the same thickness. Also, look up hammer-welding for an explanation of the process that created all of the great custom cars of the 50s and 60s...