Keel bolts protection

[suffolklass]

Apologies as I know this has been asked before, but I'd love any specific product recommendations!

Our new-to-us boat has had water sitting in the bilge for a while. The surveyor didn't have any concerns about the keel itself, but the keel bolts were previously painted with 2 part paint, the paint has chipped away in various areas and the top of the bolts and washers have some surface rust. We'd like to remove the paint, clean up the bolts and then protect against any condensation or further water ingress.

So wondering about recommendations for:
- Removing 2 part paint (a big wire brush will be one thing but it's been unevenly applied so there are some thick areas)
- Is it worth using a rust treatment or just wire brushing once the paint is off?
- What to put on once the bolts are cleaned up to prevent them rusting again - we can't guarantee that the bilge will stay completely dry, so I think probably best to do something. I know people have mentioned car underseal in the past but there seems to be variation in types, and then some people also recommend painting but is it better to use a clear protection layer so you can see any future issues?

Anyway, all thoughts appreciated, especially links to particular products that you've used and found good.

Thanks all!

 

[vyv_cox]

The coating applied from new is flocoat, gelcoat with added wax to prevent stickiness on the surface.

 

[suffolklass]

Thanks, it might be that - the surveyor said it had been painted over and he thought 2 part paint, but who knows. It'll need to come off though as it's not covering the whole thing and there's rust in the cracks!

 

[ghostlymoron2]

Are you planning to pull the bolts out? This is a wise precaution to check their condition. Only do one at a time I don't worry about the visible bits, it's the hidden parts that concern me

 

[Tranona]

Are you planning to pull the bolts out? This is a wise precaution to check their condition. Only do one at a time I don't worry about the visible bits, it's the hidden parts that concern me

Not sure why that would be so. If there is no sign of leakage through the hull/keel joint then the studs/bolts will likely be in perfect condition. the "bolt drawing" advice is generally only appropriate for wooden boats. Once the current coating of the heads is removed it may reveal corroded backing plates and nuts that might need replacement, but probably the original coating will have protected them.

 

[OCuea]

Vyv is an expert so perhaps clean as best as you can, apply rust preventer of your choice and then use the stuff Vyv says is used at production?

 

[PabloPicasso]

Use acid rust treatment like Ferton (there are many others) prime, and top coat with red oxide.

Denso tape can be used and will exclude any other moisture.

A small piece of polythene over the denso tape stops it sticking to the underside of floor board, but just cover the tops.

 

[greeny]

I've just been reading the post on Denso tape. If the keel bolts are out of the way and bilge area not used for other things then denso tape would be ideal. But it's messy to apply and remove.

 

[PabloPicasso]

I've just been reading the post on Denso tape. If the keel bolts are out of the way and bilge area not used for other things then denso tape would be ideal. But it's messy to apply and remove.

Yes, a bit messy as it self-amalgamates. That's why I suggested polythene over the top.

 

[suffolklass]

Thanks - I'll take a look at denso tape. Sounds as if a rust treatment would be worth it also.

 

[OCuea]

Thanks - I'll take a look at denso tape. Sounds as if a rust treatment would be worth it also.

You have a lot of info…… Goodluck. Denso sounds great for some applications (underground pipes, trawlers hydrologic pistons….). For your nuts (no pun intended, but I am laughing - no offence intended) I would do as you said, wire brush, anti corrosion treat, paint, then use non messy epoxy to cover ( flow coat I think is polyester based). Epoxy will be transparent, good adhesive properties, more flexible than polyester, provides better protection of penetration of water than polyester resin. Then you can view nuts and have no mess. My opinion only. Good luck.

 

[Rum Run]

I'd be wire brushing any loose stuff off then protecting with zinc-rich paint brushed on. Anything brittle like a resin will crack and let water in next to the steel again.
The zinc in the paint acts as an anode, just like galvanising, and it is easy to inspect and re-do if necessary later.