Primer for bronze thru-hulls?

[Suijin]

So since I switched to a hard bottom paint, I can't keep it sticking to bronze thru-hull flanges. The ablative paint stuck fine, but the hard seems to come right off.

I've heard contradictory advice from old yard salts about just slapping some barrier coat on them and then the bottom paint. Some gasp in horror, others recommend it highly.

The alternative seems to be a primer system along the lines of what Pettit offers, a two part deal. I have the barrier coat, would rather use that.

Thoughts? Experience? Advice?

[rognvald]

Hi, Suijin,
Two programs will work:
1. Petit Tie Coat Primer followed by the paint of your choice or,
2. Interlux Primocon Metal Primer
I have used both over the years with excellent results. Be certain to clean the through hulls properly before application and allow the total paint system to "kick" before splashing your boat. I hope this helps. Best, Rognvald

[Suijin]

Thanks Rog.

Looks like I need to use a primer first, then the tie coat. From the instructions, for bronze:

Clean surface to be painted with coarse scotchbrite pads and Pettit 95 Dewaxer. Abrade to clean, bright metal by sandblasting, sanding or wire brushing. Blow off or vacuum sanding residue and immediately apply one thin coat of Pettit 6455/044 Metal Primer. Let dry two hours and apply two coats of Pettit 6627 Tie Coat Primer, allowing the proper dry time between coats (see dry time chart) before sanding lightly with 80 grit sandpaper and applying appropriate antifouling paint.

Fair enough. The yard has this stuff. Now I just have to convince them to let me use it instead of charging me $80 to apply it...

[Orion Jim]

When I barrier coated my hull I just rough sanded all my through hulls and barrier coated them at the same time. InterProtect has excellent adhesion to bronze in my experience.