Aluminium rich epoxy over cold galvanised mild steel?

[Ric]

I recently stripped back my keel bolt heads, painted them with cold galvanising zinc paint, then sealed them over with several layers of Aluminium rich epoxy primer which I had lying about.It subsequently occured to me that this was sandwiching the zinc between two more noble metals. I just wondered what sort of galvanic reaction might occur?

 

[VicS]

I recommend that you consult the manufacturers data sheets for the coatings you have used.

They should used in the way specified , ie to suitable substrates, preparation, prepriming and overcoating.

 

[MM5AHO]

There's no such thing as "cold galvanizing".
There's paint, with zinc dust contained, but that's not galvanizing.

Galvanizing is a completely metallic coating of zinc, and zinc-iron alloys.

Paint is a resin inside which are zinc dust particles, electrically insulated from the steel by the resin of the paint, rendering them far less effective in conducting electical current that constitutes rust.

As for mixing Al and Zn, as its all in paint, bound in resin, where the metallic contact? If no electrical contact, then no galvanic reaction.