Unable to use Magna Weld dent puller

[kltarga72]

I'm trying to pull a small dent out of the bottom pan near the front torsion bar. I removed the under coating and used wire brush to make sure I have a clean metal surface. Using an Eastwood Magna Spot Weld dent puller I was unable to weld a pin to the clean metal. I'm able to weld scrap sheet metal so I know the spot weld unit is working like it should. I see when I push the welder up against the spot it makes a few small sparks like I have a dirty surface and not making good electrical contact. The spot is super clean.

Does this problem I'm having anything to do with Porsche and galvanizing sheet metal for rust protection? I have a 1980 SC.

Thanks
Lash

[john walker's workshop]

Mmmm, could be, eh?

[kltarga72]

Originally Posted by john walker's workshop

Mmmm, could be, eh?

I have successfully welded pull pins many times, many different cars.
Today I have test welded pins to four different pieces of scrap metal.

I hope someone else can shed some light on this problem.

Lash

[jjeffries]

Maybe sand down to shiny metal in a couple of places and retry? That's what I'd do. I have a similar machine and find it easy to use. Best of luck, John

[kltarga72]

OK
I fixed the problem, used air sander on dent and Emory cloth on Magna Spot welder and I was able to weld pins to the dent.
One of those days, and now its after 5 o'clock here.

Lash

[dicklague]

Originally Posted by kltarga72

OK
I fixed the problem, used air sander on dent and Emory cloth on Magna Spot welder and I was able to weld pins to the dent.
One of those days, and now its after 5 o'clock here.

Lash

Good for you. It is too simple a circuit not to work. Good ground and good clean surface for the pin.

[911pcars]

Yep. Good ground connection nearby. In addition, disconnect battery less you fry some electronics.

[RetroSC]

Maybe the galvanized chassis coating was giving you problems, needed to grind down to fresh metal.

[kltarga72]

Originally Posted by RetroSC

Maybe the galvanized chassis coating was giving you problems, needed to grind down to fresh metal.

I had used a wire wheel to remove the undercoating and I had what I thought was a clean metal surface. Only after using air sander to further clean the dent was I able to weld the pull pins. Possibly there was some type of coating that did not allow a good electrical contact.

I make it a rule to always disconnect the battery when working on cars.

Thanks everyone for your input.

Lash