3M Weld-Thru coating II vs Cold Galvaizing? What do you choose?

[BrownCoat]

The vert project that I bought has a lot of bare metal welds. I have a can of 3M Weld-Thru Coating (its not the same as weld through primer to my knowledge) but I've been hearing a lot about Cold Galvanizing compound. Cold galv is a lot cheaper.

Which do you like and what are the pro's and cons in your opinion? I still have to finish a lot of the stitches and spots that the PO started but it's starting to get some surface rust due to all of the humidity around here so I need to protect what's there while I finish the rest.

[theKbStockpiler]

I have done one task with weld thru primer and I would only use it on the inside of panel with no access after it's welded up.

I tried to do small stitches to hold a panel on and the arc struggled to burn through the stuff and it displaced the shielding gas. On a long seam I will try it but that is it.

I have heard that some people just use spray on zinc with decent results and you have to remember with either to have LOTS of ventilation and at least one fan removing the burned off product. High temp paint works to some degree.
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[BrownCoat]

Thanks for the reply. From what I've read this 3M Weld-Thru Coating is different than weldthrough primer. This stuff is mostly zinc. I have a great, well ventilated area so there's no chance of exposure to the gasses.

[modok]

I'm using one that has some copper as well as zinc, gold in color, i think it works a lot better.
Remember it is only for seams and overlaps, but since that is where rust usually starts, i think good idea. just sand off the excess.

[theKbStockpiler]

I'll be in a 'welding phase' in the next couple of months so I can do a few tests with it unless someone beats me to it.

I read where you could coat both sides of the seam ,arc through the stuff and it would encapsulate the weld bead with no issues.

I was doing a small project that was a lap joint so I decided to try the stuff out. Basically it worked like I was welding contaminated metal where the arc sputtered ,there was no penetration and the weld bead built up,also known as Edit: hammered dog crap welding. I removed the stuff from the surface and the residue under the seam still made the pool resemble a low voltage condition on dirty metal There is no way in hell you could do a series of spot welds with it and have it work out decent. Maybe if the arc struggled just until the primer burned off and it worked fine after that. When I get welding again I'll post my results with some pics.Maybe I had it on too thick or it was not dry enough.
_________________
My beetle is not competing with your beetle. I have the yellow beetle in my town. There is a red one, a green one ......
Use all safety devices including a mask.

[themetalsurgeon]

3M weld through,not galv process imo
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