Mig welding Galv??

[nigelr32]

Hi all,

My project car is galvanised. It will be seam welded and have a weld in cage fitted to it.

I'm looking for suggestions to locally remove the Galv in a pretty precise area, but without thinning the sheet behind??

Regards

Nige

 

[irondarren]

Galv is nasty to weld. the fumes are bad for you and it kills welding tips and shrouds. the normal method is to grind it off, but obviously you are worried about thining the sheet. A bit of an off the wall suggestion and i really dont know if it will work, there are such things as stainless steel polishing discs, very similar to flap wheels. not sure if they would remove the galv (as zinc is relatively soft) without damaging the base material. problem is they arent that cheap.

 

[shenion]

Flap disks will work if you grind lightly.

It has been mentioned before to use acid. i tried muratic acid and it seemed to work well.

 

[matt1978]

You could also try Mig Brazing.........it still wont be pretty or fume free but would save the job of removing the galv off the local areas you want to weld.

Depends on the thickness of the galv as to weather its worth considering or not, is it hot dip?

 

[nigelr32]

It's a brand new shell, Fiat actually, and it has a good, thick, shiny coating of Galv on it. I can tell this because I've spent days now removing seam sealer and a wire brush in a drill doesn't touch the Galv as far as wearing it off goes.

When you all suggest flap wheels, do you mean the grinder type of flap wheel, or the sort you put in a drill??

I guess some Galv will remain "in" the seam, but I suppose that won't hurt as long as I wear a mask when welding?

Regards

Nige

 

[Weldingartisan]

It certainly won't be hot dipped if it's a body shell. I'd guess it will be electro plated only a few microns thick something like zintec. In which case I would just go for it with a fume mask, as long as the weld quality looks OK. W/A

 

[Warren 2]

I tried tig welding galvanised legs to my mild steel top to make a work bench. Just spat and popped! Tried grinding it first but this didn't get rid of all traces so used a gas torch to burn it off, even this didn't get rid of all traces lots of fumes tho so however u do it wear a mask! I guess if ur using a mig it might not be so crucial to remove every last trace so a grinder might do it. I got a air sander with those 3M Rotolock pads, u could give those a try, they dont remove much material.

 

[arkangel06]

get a little air die grinder and some scotchbrite pads

 

[Finalreminder]

get a little air die grinder and some scotchbrite pads

Like gold dust those pads.
Unless you know a supplier?

 

[Robotstar5]

We use rolls of "scotchbrite" type abrasive at work from Wurth

 

[madkayaker]

very good also for cleaning 30+ years of paint off pipes to get earth clamp on.

 

[Robotstar5]

very good also for cleaning 30+ years of paint off pipes to get earth clamp on.

Slight hi-jacking of thread, had our gas meter changed, fitter removed earth clamp to remake pipes and just throws clamp to back of meter box saying it's not his job to refit!

 

[madkayaker]

he needs shoping it is most definatly his job to refit.