Patches of gel coat worn through below waterline, what to do?

[MissFitz]

I recently got my boat out of the water for the first time since buying it & have discovered that, where last year's antifoul has worn off, there are several patches where the gel coat has been worn away. It look as though the previous owner decided to take off several years' worth of old antifoul & primer, & got a bit too enthusiastic. Unfortunately, he also seems to have lost interest around the keel. So what I now have is a below waterline hull that is mostly white gel coat, with several patches where the gel coat has been worn through, plus about three inches width of a thick layer of old primer/antifoul over rust around the keel join (cast iron keel). Plus there are still a few patches of old primer elsewhere.

From previous posts, it looks as though the best solution to the thin/non-existent gel coat would be do the whole hull in two-pot expoxy. However, getting the old stuff around the keel join cleaned off for that will be a pain (I spent half a day sanding it this weekend & didn't make much impression). So my question is, is there a quicker way of getting this sorted out that won't compromise the hull? Could I put expoxy just over the patches where the gel coat has worn away, treat the rust on the keel, & then put primer over the lot?

Just to note, the reason I'm keen to go for a relatively easy solution is not because I want to be a bodger but because a) I don't have that much time to work on the boat, b) the sailing season is fast approaching, & c) most importantly, I'll have to start paying to be on the hard standing in just over a month.

All help much appreciated, as always.

 

[RichardS]

It sounds as if the best solution would be to have the whole hull blasted (soda/ice/whatever) by a professional company so you can clearly see what it all looks like, before deciding what to do. Obviously, this will cost and might be outside your time scale.

Richard

 

[johnalison]

I agree that you will need to do the whole lot sooner or later. Depending on the size of the problem, you could have it blasted off (which I did) or work on it with scrapers +/- a/f stripper. If you want to get sailing this year, you could do as you say, and deal with the affected areas as well as possible and prime, so long as you treat it as a temporary measure.

 

[lw395]

Prime the bare bits with epoxy.
Plan to epoxy the whole underwater area next winter.
If you are happy to stay ashore for another month, then consider epoxying the lot this year.
I can't immediately see why dealing with a 3 inch stripe around the top of a Sonata keel is such a big deal? Maybe it has been coated with something like epoxy already which is hard to sand? IIRC the Sonata has a T-shaped keel with a wide top which is housed in a recess in the hull? Often faired with godknowswhat? With a ring of sealant around the keel top? If that's all sound, leave alone and just W&d it and antifoul. If the main body of the hull is dry and free of blisters, a few coats of epoxy would be good.
Has the boat been out of the water a lot in the past?
The sailing season is already here BTW.

 

[coopec]

I don't disagree with what OP have said but if time is limited you could sand the areas where it is worn and apply 3 coats of epoxy barrier coat.. The hull would need to be dry and anti-fouling would have to be applied over the barrier coat the same day (but follow the paint manufacturers directions)

 

[MissFitz]

I can't immediately see why dealing with a 3 inch stripe around the top of a Sonata keel is such a big deal? Maybe it has been coated with something like epoxy already which is hard to sand? IIRC the Sonata has a T-shaped keel with a wide top which is housed in a recess in the hull? Often faired with godknowswhat? With a ring of sealant around the keel top? If that's all sound, leave alone and just W&d it and antifoul. If the main body of the hull is dry and free of blisters, a few coats of epoxy would be good.
Has the boat been out of the water a lot in the past?

I think the boat has spent most winters out of the water, as well as being dry sailed in its heyday - at any rate, hull seems to be completely free of blisters.

Re the keel - the reason I mentioned the 3-inch stripe of old stuff is that I'm not sure what to do about it if I'm going to epoxy the whole hull. Do I need to get it all cleared off or would I be able to epoxy over it? I'm also not clear on whether I should be looking to epoxy the keel as well. Plus there is a clear line of rust at the keel join & the bits around it are a bit lumpy, which I guess means there may be more rust underneath that's been painted over. If I were going for primer/antifoul then I'd just sand back round the rust line, apply Fertan extensively & then go for it, however not sure that would be ok if planning to epoxy.

The sailing season is already here BTW.

I know!! Unfortunately was ill over the winter so boat stuff had to be shelved, hence keenness to get on with stuff asap now!