Welding Tips and Tricks

I was working on my porta band stand yesterday. Most of it was being made out of some cheap galv rectangular tubing. I cleaned off the galv with the grinder and gave it a quick wipe down with acetone. Done this plenty of times with no issues. Yesterday however I could see the puddle bubbling kinda like it was boiling. I figured it was some galv coming up from the bottom. I was using 1.6mm 70s-6 wire at the time. As an experiment, I grabbed a rod of 2.4mm 70s-2 which was a bit too big for the tube but it puddled nicely. I finished out the rest of it with the larger rod. Any thoughts?

If it were the galvanizing, you should have seen that purple glow around the arc, and possibly some smoke.

Maybe an impurity in the base metal, like an inclusion or corrosion pit of rust? Some organic the acetone didn't completely remove? The heat you introduced welding with the -s6 may have been enough to cook it off by the time you put the larger rod to it.

Also, perhaps the smaller rod had a contaminant (grease? silicone?) on the surface, if you set it on the bench at some point? If you only saw bubbling just after adding rod, this might be the case.

This is just speculation, of course, but the only things I can think of immediately that would explain the rod change solving the problem.

Steve S

You are aware that the gas from welding galvanised will kill you! I'd buy some mild steel tube at my local hardware store.

While I'm not gonna pretend to like galv, I will say that I use a P100 mask and clean off most of it before working with it. I'm no stranger to working with galv and I've yet to get the shivers.


Been meaning to reply to this anyways. I plan on going out and running some tests to determine if it's the filler or the metal that's causing it. It's just too flippin cold out there right now.

gary roushkolb wrote:You are aware that the gas from welding galvanised will kill you! I'd buy some mild steel tube at my local hardware store.

I've been dead a long time.

The zinc oxide in the smoke will make you feel like hell the second day, then it passes. Welded it for months w/ flux-core and no breathing protection.

Nasty work. Wipe the haze off your lens every ten minutes.

One positive effect from the zinc... I didn't have a cold for about a year and a half.

Steve S