1 reply to this topic

[mickyh]

Over 18 months ago I coated all the interior metalwork and underbody with Electrox, even though it has been stored in a damp garage every panel that was primed is still free from rust, the underneath has been coated in stone chip and I have moved onto the upper body.
I now want to offer the same protection to the upper body, I was wondering has anybody applied a high zinc primer such as Electrox with a brush and then flattened back?

[bluedragon]

If this was for visible. external body panels that will be painted and finished, I wouldn't use such a primer unless your plan is to strip it off before painting them.

 

I admit I do not have personal experience with the Electrox product, so I'd defer to those who do. But typically zinc-rich primers don't have the adhesion or smoothness to serve as a good undercoat for finishing primer and paint.

 

It doesn't actually adhere that well to metal compared to epoxy primer or self-etch - not a big problem on the backside of a panel or interior, but more likely to fail when subjected to the thermal and physical stresses on the outside. And most I have seen don't sand well for a smooth finish. If you wanted some sort of zinc-based primer for exterior panels, there are zinc chromate primers available, designed to be undercoats for painting. These are less common though than epoxy or self-etch.

 

If the panel is going to be stored for a while pending final finishing, I would use an epoxy primer. Then prior to finishing, when you get around to it, scuff the epoxy primer, spray another coat of epoxy primer, then complete your body finishing (high-build primer, final sanding, and topcoats) on top of that within the recommended time window. (That way, the topcoat materials will chemically bond and link to the epoxy primer coat as well as mechanically adhere, giving the maximum in adhesion and durability.)

 

 

Dave