Rust spots on bilge keels

[Marceline]

Hi - were about to buy our first boat - found one we think looks great overall and has coppercoat antifoul which looks ok (been on 7 years)

but there re some spots of rust on the bilge keels, more so at the base where the boat has rested on low tides

should we try and fix them before we launch back into the water (Menai Straits area) as worried if they may get much larger, or will they be ok for the rest of the season?

if fixing, would just painting on some extra coppercoat be ok, or would it be grind everything back and reapply big job ?

 

[chris-s]

I shouldn’t worry about it, at least for now, they wont fall off and it’s a job you can tackle off-season.

We have a bilge keeler that had horrendously rusty keels. I tackled them a a season without being able to use a sand blaster, the only tool which would knock the scale off was one of those Tercoo rotar drill attachments. That, phosphoric acid and plenty of coats of good primer. Then it’s just a question keeping on top of it over the following seasons. Since ours only dries out when hauled out for winter, that’s when most of the rusting seems to occurs so I’ve made it part of my winterising programme to at least treat any patches on haul out.

 

[MikeCC]

It's June, do the minimum amount needed to get on the water!

WIth Coppercoat, it's not a simple matter of just painting some on, so a quick job is likely to be a waste of money.

For this season, you could grind back the worst spots, apply a couple of coats of epoxy primer, coat of vinyl primer and then regular antifoul.

As it's a bilge keeler, you have the 'easy' option of beaching to inspect/scrub off if needed.

You'll have time in the autumn to decide what to do next.

 

[MikeCC]

If you spot repair now, skip the Fertan type phosphoric acid type rust treatments. Just get to bare metal, clean with thinners and put epoxy primer on straight away.

 

[Marceline]

thanks for the replies and advice - really helpful

 

[Refueler]

mmmm on seeing the title - I read the first post to see what form of bilge keel ....

Judging by the replies - it seems the BK's may be plain iron plate keels ? Painted over ? If so - then take back to clean metal - prime and antifoul.

But if the keels are GRP with encapsulated ballast - often in pig iron form .... then rust spots can indicate a more serious problem. The spots being breakthrough of the GRP from the failing iron inside. Pressure can build from increasing rust formation and lead to burst GRP.

 

[Marceline]

thanks for the warning Refueler - I think its just basic iron keels (hopefully) but we're having it surveyed so hopefully we'll get confirmation either way

 

[vyv_cox]

Coppercoat sell small kits for patch repairs. It is worth doing before you launch, will only take a day, as rust penetrating beneath the CC will blow the rest off.

 

[chrisD]

Assuming they are simple iron keels, do rust spots really matter? I have owned two Westerlies with superficially rusty keels and have just given them a quick annual scrape and anti foul. I don’t think they have lost any significant weight through a bit of surface rust, so have never bothered to do anything more, partly as I suspect it would be a losing battle. But I stand to be corrected.

 

[vyv_cox]

Assuming they are simple iron keels, do rust spots really matter? I have owned two Westerlies with superficially rusty keels and have just given them a quick annual scrape and anti foul. I don’t think they have lost any significant weight through a bit of surface rust, so have never bothered to do anything more, partly as I suspect it would be a losing battle. But I stand to be corrected.

With conventional antifouling paint what you say is correct. A few rust spots do not matter in the slightest. This is not the same for Coppercoat, which is what OP has. Rust penetrates beneath the epoxy and blows off large patches.

 

[LONG_KEELER]

Not applicable in this case but I used Hammarite no1 , red, three in one rust treatment on my keel.
This was after two years continuously in seawater. At the time, I just dabbed it on the rusty bits of metal which you can see. It's the only thing that's really worked.

 

[JimC]

Not applicable in this case but I used Hammarite no1 , red, three in one rust treatment on my keel.
This was after two years continuously in seawater. At the time, I just dabbed it on the rusty bits of metal which you can see. It's the only thing that's really worked.

+1 for Hammerite No1 Rust Beater