Weld-through primer?

[Keele81]

For years I've considered trying weld-through primer to protect from rust at ground points, but I've never actually tried it. Anyone have any information or experience trying this? I've used it for welding & I'd think if it can handle passing current to form an arc shouldn't it work to pass amperage of a amp ground?

Thanks for any info. One of those old "highdeas" I've kicked around, but never looked any further into.

[WOOSEY]

How many Amps does your welder use for the arc?

Maybe measure the stuff with a DMM... just put the probes in the primer and see if it conducts...

[IBcivic]

IDK about weld-through primers...but primers in general are poor barriers because of their porosity.

[Fricasseekid]

I may be wrong here, but I don't think a weld through primer is used for its conductive abilities. It's probably used because of its ability to burn off without contaminating the weld.

[Keele81]

I have only used it on sheet metal, 10 gauge or less generally, so I haven't used but around 150 amps or so max. In theory it has always seemed to me like a good idea for protecting from corrosion. Aside from being the test dummy it's hard to say it would even work

[Keele81]

I may as well give it a try, so I've hooked a piece of aluminum channel I had setting to negative battery post & checked voltage.

12.63 at battery post
12.63 at pos post & alum channel

Two coats of weld-it
12.63 at pos post & end of coated alum

Then I added 2 more coats ,4 coats total, of weld-it (3-m weld-through primer)
12.63 at pos post & end of coated alum

3-M only calls for one to two coats 1 mil thickness max, but I did double to insure I was getting readings threw the primer. Seems to be conducting, I'd only figured it would conduct ok because it contains a good deal of zinc & alum.

Now any recommendations on checking amperage or any flaws in my initial testing? Thank you all for your time & input!