Cast iron keel and anti fouling

[jfkal]

What are the consequences of NOT having my iron keel sandblasted and epoxy coated but just lightly sanded (just a few rusty pocks) and plainly antifouled on top? (Besides saving me a lot of money I mean ;-))

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[Evadne]

I've been doing it for years, you get a few rusty marks by the end of the season and a progressively more knobbly keel. But that's it. If you feel a smooth keel would make you go faster (until the barnacles take up residence, that is) then get it sandblasted and faired, or try a couple of coats of interstrip and a good scrape. That gets the surface pretty smooth without having to go back to bare metal.
I'd be interested to hear from anyone who has done it: just how long does the finish last?


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[jfkal]

Thanks. That's what I had suspected. Shall leave it as is. A golf balls flies better with dimples as well after all )


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[seaesta]

I have done this for ages also BUT I do use the proprietry "rust cure" products that turn rust "into a stable base coat". This seems to work well the last one I bought was called "ku rust" and it formed a pretty good undercoat for the antifoul. This approach minimises wire brushing and consequent exposure to nasty toxic dust
Martin

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[chas]

I gave mine a good going over with a wire brush and three coats of Hammerite three years ago. Since then, I have only had to patch the odd rust spot (again, wire brush and Hammerite). The antifoul seems to stick well to the Hammerite.

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[ccscott49]

Try scraping and painting with "Osfor" the best rust killer I've ever seen, I believe it's mainly phosphoric acid. Great for removing rust streaks on topsides aswell. Not to mention removing "waterway smile"


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[squidge]

This year I tried something else, go it back to metal with a grinder then a coat of POR paint from frosts (paint over rust) , a tie coat primer ,2 coats of antifouling primer and then the antifouling. Looked great but will have to wait till shes out again to see how it all works(POR had a lot of good recommendations) If it dose work it will be less than 1/2 the price of blasting./forums/images/icons/smile.gif

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[Guest]

Power file or angle grind rust spot back to bright metal.Prime IMMEDIATELY with Blakes Keel Prime.Then 2 more coats of Keel Prime (time betwen coats will depend on temperature) - I did mine on a warm spring day in the yard with the first coat early am then second late pm third coat early am next day and was able to antifoul that evening.When I first did it there were large patches of rust on the keel which i treated as described.The following year there were a few rust spots in untreated areas and a similar amount this spring.It seems that Keel Prime really does do what it says on the tin.The keel is a bit dimpled in appearance here and there but I am of the opinion that this is cosmetic and has a minimal effect on performance.In any event I only cruise her so I can live with any increased drag.When I first saw it I was thinking of having the entire keel shot blasted but my brother talked me out of it on the grounds that the less bare metal exposed to the air the better and it is better to spot prime as described above.I discussed this with my surveyor and the yard and they agreed - for what its worth.

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[PeterGibbs]

Consequences? None whatsoever. Slaving over every scrap of loose paint and each rusty spot on a keel is work for the possessed, not the balanced sailor - at least in my book. You could not measure the effect on speed from such imperfections, and there is no way that damage to the keel could result from such (lack) of treatment.

However, if there's any problem at the keel / hull join with sealant falling away or rustiness appearing in the bilges around the keel nuts, that's a different matter.
This could lead to movement which is very much in your interest to fix. Pronto.

PWG


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