Weld through primers, a question for the restorers and home welders

[olives17]

Good day folks

I am currently restoring my W116 (350SE Euro '74) and was wondering what kind of weld thru primers were being used by people out there between overlapping sections and why (upsides, good/bad experiences etc.)? I myself have been using INOX spray (got the tip from Greasy fingers on youtube), what do you use?

- Oliver.

[rumb]

You would want to do whatever steps are needed to prevent new rust, as well as remove or neutralize any existing rust. Try to cut back to good clean metal, and if that is not possible or practical then use a rust converter. Any Weld thru primer is good, however using lap joints is problematic as that leaves an area for water to get into later. Butt joints are always better. I would use weld thru primer as needed and then topcoat everything you can after welding.  Primer is well...primer.  Should be topcoats whenever possible.

I'm not seeing any INOX primer products,  do you have a link?

https://www.inoxmx.com/products/

[olives17]

Hi and thanks for the reply.

Yes I wholeheartedly agree, butt-joints are the way to go for rust repairs. What I meant that I probably didnt specify enough was the overlapping sections from the factory such as the floor to the inner rocker, or the outer rocker flange to the inner rocker flange and so on.

Basically inox is stainless steel I think. couldnt really find any english/american link to it, might just be a European thing.. heres a norwegian one.. https://www.kemtek.no/products/inox-spray ,Thats the one I got, and a german one with an english webpage: https://en.foerch.com/chemical-products/base-coats-body-protection/weld-spray/inox-welding-spray-l234 . As you might see the one I got is out of stock, and so I was wondering what other people used.

And as you said, primer is primer and should be topcoated whenever possible.

[rumb]

That is an interesting product. It is however not a weld thru primer, which is important or you wont get a good spark/heat when welding.

 "Use for protection of temperature-exposed parts such as the exhaust system, machine and machine covers, bathtubs, pipes, tanks and other places where appearance is important,"

I'd find a more basic true weld thru primer.

[ptashek]

I haven't used it myself in welding applications, but know first hand someone who has and recommends it: Normfest Galva 97. It's a weld-thru zinc primer, something like 90% zinc by volume.

[rumb]

Be careful of toxic fumes when welding zinc!

[olives17]

Hi again and merry christmas:)

Ive see the galva 97 being mentioned other places as well, so it must do something right. Ill definetly look into it once I get home from the family visit!

Had a second read on the website of the INOX spray, and youre right rumb, nowhere does it say its a weld thru primer. I digged a bit further and found the technical datasheet from the manufacturer, and it states that it was developed for use with resistance spotwelding and shielding gas welding among other things.

Just cut out a section of the inner rocker and floor I had made where I used INOX as a primer between sheets, Think I'll open it up and have a look.