Weldable Primers and Picklex 20

[andrew3]

Greetings folks. Im new to the forum and working on some metal repairs to my 67 Mustang Coupe.
I have cut the bad metal out and I am preparing the surfaces to weld the new metal in. I bought some picklex 20 from here a few months ago, but I have read alot about 3m Weld through primer. Once I get the surfaces I am welding down to bare metal, is it a bad idea to coat with picklex 20 and then weldable primer? I want to get the max protection between the panels as possible, but dont want to use incompatible coatings or waste materials.
Thanks
Andrew

[AlexeiVT]

No problem w/ doubling up on protection for peace of minds sake, as I too take the same approach.

For that matter, though Picklex is a great rust inhibitor and welding aid, and protects against flash rust in a "dry" environment, it's not meant as a waterproofing protection between lapped panels.

That's where the weld thru come in, and as best I can tell, no problems w/ adhesion of a weld thru primer over Picklex (though they both may have zonc/phosphate, it's not the potential delam issue it might be if you were to spray etch primer over either).

In my experiences, 3M's weld thru primer was about the worst performing, it negatively affected the weld process, plus whatever is left over from the pricey can, is a forgone cost unless you cut open the can and brush it, since (at least my can, and a few other people's) didn't hold the charge...welding through cold galvanizing spray produced a better (though still unacceptable) result, than 3M.

Autotech also didn't fair too well, despite their claims.

Standox 1K worked well, but I'd still always opt for the U-POL...after spending $40+ on cans of products that didn't work, U-POL actually does reduce spatter and help the process...all the more important as a novice...remember, cleanliness is king, and cut the blob off the end of the wire before you strike the arc.

[Len]

Yep, U-Pol is the stuff. We use it here, much better than most other products on the market.

U-Pol Weld-Thru Primer Link

[TimG]

3M now makes WeldThru 2,it ALL comes out of the can.
Welds WORSE than the original,go w/ the U POL!

[andrew3]

Thanks for the responses guys. I'll see if I can find the U-Pol locally.