Rust inhibitor

[NYSail]

Hello all…..

so my beneteau keel has small rust spots every season that need to be addressed. In the past after grinding/sanding, I have been using POR-15 and top it off with petit 2000, however it appears to not be holding up. I have heard many folks use Ospho as an inhibitor. Would love to hear others experiences.

thanks!

 

[dlochner]

I'm currently working on a steel boat with raw steel and older steel with failing paint. The protocol we are using is to:

1. Take steel to bright metal
2. Treat with TotalBoat Rust Primer
3. 2 coats of Total Boat Epoxy primer
4. Finish coat.

It is important to treat the bright metal quickly before any oxidation occurs and let it work over night. The epoxy coatings are necessary to ensure no moisture reaches the metal.

Ospo and the TotalBoat Rust Primer are probably similar products. Both are Phosphoric acid which bonds to the steel preventing rust and providing a suitable surface the primer.

 

[dLj]

Ospo and the TotalBoat Rust Primer are probably similar products. Both are Phosphoric acid which bonds to the steel preventing rust and providing a suitable surface the primer.

Phosphoric acid primers covert iron oxide into iron phosphate which is an inert oxide similar in structure to aluminum oxide which is what protects aluminum alloys. Just a FYI

dj

 

[JBP-PA]

That's a pretty reasonable approach for touch up spots. I do something similar on my cast iron keel and it seems to hold up well.
What do you mean when you say it does not appear to be holding up? That's spots you treated last year reappear? It is flaking off? That would imply poor adherence. After sanding/grinding, are you doing the whole POR-15 three step system: degreasing thoroughly, using their metal prep (which I'm guessing is an acid etch), before POR-15 paint?