Preperation and Antifouling

[Rowana]

The antifouling on Rowana is in good nick EXCEPT on the cast-iron keel, where it is coming off in lumps.

What is the falorum's view on the best way to proceed?

Am I faced with getting it all off the cast iron bit, then priming it with "something" before A/F? Or is there merit in just getting the loose bits off before priming and A/F?

Your thoughts please, guys

 

[robbieg]

Unless you want to get the keel grit blasted & then paint straight away you are pretty much wasting your time in trying to get a long lasting smooth surface-unless its properly taken back to bare metal then the rust will come back. My solution is to clean up the worst of it, slap some more a/f on & go sailing.

If you search on this subject you should find some interesting posts-if you want to learn more about grit blasting & how it should be done look for some of the posts by Oldsaltz.

 

[richardabeattie]

If there is the slightest crack in your antifouling the sea may get to touch the fabric of your boat. Your boat, its contents and all the people on board will then disappear in the cloud of methane emitted from the backsides of all the teredo worms and giant molluscs who will be gnawing at your bottom. Or maybe not.

 

[Lakesailor]

Yes to both. Don't get paranoid about iron keels. The boat will be dead long before the keel rusts away. Just put something on to stop the wildlife sticking to it.

 

[boatmike]

Depends how bad it is. I agree with others that it is common and not a worry to the structure as cast iron won't melt away. However if you just slap more on over flaky rusty iron it won't last long. Shotblasting is best but expensive. If you wan't to do a proper job without, it's down to scraping all the old stuff off, wire brush all over to remove rust flakes, and painting the keel with a rust stabiliser before new antifoul. There are several paints available on the market now that you can paint over bare metal. None will stop the rust reappearing for ever but they work quite well for 2 or 3 years.

 

[Rowana]

That sounds like it's the way to go.

Thanks all.