Deck fittings on Balsa core

[sgjfrods]

Hello – I am looking for some advice. I have a Westerly discus that is currently on hard standing whilst some work is being done on it. I have read much about leaking deck fittings rotting the balsa core without any tell tail signs until it is too late and much damage is done. Whilst i have the headboards down i have been inspecting the through deck fittings for any signs of moisture. Most seem to be in near perfect condition aside from one which looked blacker and was slightly mouldy. I have removed the suspect bolt and found a hole with no epoxy and a slightly damp balsa core within the hole. As these were factory fitted deck fittings i was expecting an epoxy filled surround and was disappointed to find a bolt which could deliver moisture directly to the core. This leads me to the question are any of the other fittings causing a problem? I am loathed to remove each and every deck fitting to check for moisture, fill with epoxy and re-drill as I would not like to try and fix something that may not even be a problem, coupled with access to some fittings being difficult. Does anybody have an opinion on this? Are there any tell-tale signs to know if a fitting is leaking without going to the trouble of removal? Are there any less intrusive preventative measures that anybody has tried e.g re-sealing around deck fittings to prevent water running between the fitting and the deck? Any help/advice or opinion is much appreciated.

 

[Supertramp]

I suspect the Westerly Owners Association would know the details of construction, as would Concerto if he's around.

Based on my own boat (Cromarty 36, similar era), I was surprised at the number of deck fittings and fastenings that had no core protection other than the assumption that a tight fitting wouldn't leak and some bedding sealant around the join. I have removed quite a few for repairs and replacement and most had no sign of water ingress which is reassuring. The only leaks were one bolt on a jib track and a deck mast cable fitting (which was the cable not the fitting). No core damage with either.

I have used epoxy to fill some holes and redrilled, lanolin on the threads of some small screws, butyl rubber sealant (strip on a reel) to bed fittings and I use a ring of sealant around the top of the screw or bolt. It is much easier to clean off or remove than silicone or adhesive style sealants.

The best way to monitor is to check for leaks and moisture at the edges of interior lining panels and careful inspection whenever one is removed.

 

[Gsailor]

To OP Moisture meter any use?

(Is epoxy any good as a sealant - is it not a bit brittle?)

Some people swear by this thin sealant - it never worked for me:

captains creep sealant - Google Search

But others found it worked. Love the use of lanolin in post 2.

I like your idea of sealing around the fittings from the outside- a neat job could be made with that blue masking tape perhaps. Perhaps use the Captains thin creep sealant stuff first (consistency of water) and then seal with CT1 or your choice of sealant.

Seal over any screw heads with transparent sealant? Again you could see if they creep sealant soaked down past them screw or bolt heads and along the thread before sealing over.

Shame the builders did not appear to seal at construction.

 

[Poignard]

If you do need to do any repairs, sections 5.1 and 7.2.1 of this book might be helpful

https://wessexresins.co.uk/wp-conte.../08/Fibreglass_boat_repair__maintenance-1.pdf

 

[Boathook]

To OP Moisture meter any use?

(Is epoxy any good as a sealant - is it not a bit brittle?)

Some people swear by this thin sealant - it never worked for me:

captains creep sealant - Google Search

But others found it worked. Love the use of lanolin in post 2.

I like your idea of sealing around the fittings from the outside- a neat job could be made with that blue masking tape perhaps. Perhaps use the Captains thin creep sealant stuff first (consistency of water) and then seal with CT1 or your choice of sealant.

Seal over any screw heads with transparent sealant? Again you could see if they creep sealant soaked down past them screw or bolt heads and along the thread before sealing over.

Shame the builders did not appear to seal at construction.

Back in the 70's and 80's a lot of builders didn't bother with protecting the cores and just relied upon the sealant that does fail. I don't think that they expected their boats to still be around over 50 years later.

 

[Gsailor]

Back in the 70's and 80's a lot of builders didn't bother with protecting the cores and just relied upon the sealant that does fail. I don't think that they expected their boats to still be around over 50 years later.

Makes sense.

I am glad they didn’t have computers to tell them how thick to lay up the fibreglass because all my old boats were laid up very thickly; nice solid boats.

 

[Concerto]

All deck fittings (except shroud plates) that were factory fitted will have the nuts glassed over for extra protection against leaks. If you see any nuts with the headling down, these were a later fit. So the problem fitting is due to an owner not realising he was fixing in a balsa core area. Short term this would be fine until water got into the balsa core and rotted it. The fitting should be removed and an alum key inserted into the balsa core remove a ring of material. Seal holes under the deck and fill with a liquid epoxy. This will stengthen the two layers of glassfibre and then redrill the holes and refit the deck fitting.

 

[Refueler]

Common remedy for cored deck and making good for fittings ... bent nail in drill ... insert into hole and spin up ... basically cutting out a larger internal hole with the nail ... doesn't have to be fancy - in fact rougher the better .... then fill with fibre filled resin ... to save having to drill - you can insert short alloy tubes to fit the bolts ...

 

[justanothersailboat]

I don't think I fully agree about a lack of glassing over meaning non original. Westerly certainly did glass over nuts on the inside for things like toerails. Perhaps on classier Westerlies, or later Westerlies, they did everything. But on more than one Westerly I've seen, the coachroof fittings were never glassed while most other things were. On my Griffon there's no trace of glassing over on the underside of the coachroof where original things have been removed, or on very clearly original and unmoved parts.

Even if they did glass over the nuts, they did not oversize and epoxy fill the holes, or even countersink the top edges to make sure a ring of sealant is squeezed against the bolt and hole when tightened down. So glassed over nuts would only help trap even more water in the core. However, mostly they got away with it - much of the deck on mine and the four or so other forty-year-old-ish Westerlies I've had the chance to see this kind of detail on is still ok. Failed fitting leading to core damage and rot can happen and is really bad, but I would not assume widespread damage from a black spot and small damp patch. It does need immediate attention but everything else can be dealt with on a rolling basis. A lot of original deck fittings now are really tired and a good opportunity for an upgrade anyway. I am not convinced that immediately epoxy filling is best as there is still trapped moisture - I sealed off the outside of mine, let it dry out through the inside, then addressed the problem. Felt safer that way.

I think damage is more likely on cleats where they get pulled on pretty hard, tending to lift the sealant. Fortunately not many of these are through balsa.

 

[sgjfrods]

Thanks very much for all your helpful comments.

I agree with just another sail boat some of these fittings are definitely original and not glassed over.

I undertand that I would need to clean out, epoxy and re-drill if I were to do this, it's more the question of whether it is highly likely that a fitting of this age would be leaking in any case and therefore it would be sensible to bite the bullet and re-fit every deck fitting on the boat (alot of work) at this stage.

I am re-assured that other people have removed fittings of a similar age that weren't leaking.

There are some fittings for example guard rail stanchions that donot come all the way through the deck and screw into a locally thickened area of the deck. I assume these could also be problematic as there will be core in this area too, or is it possible that these locally thickened areas are solid fibre glass?

Does anybody reccomend any sealant that I could use on deck that is strong and would withstand a jet wash for example ?

Thanks for the suggestion of contacting westerly owners I will do this which hopefully will give me more info on the construction.

 

[justanothersailboat]

If it's like other Westerlys I've seen, the stanchions are on a non cored area of the side deck so no core worries there. They're bolted through plywood pads a bit bigger than the stanchion base, then glassed over. That produces the impression of a thick lump of fibreglass but in fact the part over the lump is just sealing against water leaking through to the inside. The ply can rot inside that lump. Fortunately they are much easier to cut open than I thought they would be.

Deck fitting sealant, Sikaflex all the way, providing you do not mind it being a fiend to remove in many years' time.

 

[14K478]

Anyone got any notes on Camper & Nicholson’s practice with balsa core decks?

Same as Westerly or different?

 

[Concerto]

There are some fittings for example guard rail stanchions that donot come all the way through the deck and screw into a locally thickened area of the deck. I assume these could also be problematic as there will be core in this area too, or is it possible that these locally thickened areas are solid fibre glass?

Does anybody reccomend any sealant that I could use on deck that is strong and would withstand a jet wash for example ?

Westerly always fitted plywood pads for all regular fittings during build and included them for extras like anchor winch or midship cleats.

My prefered sealant is butyl rubber as it is not an adhesive and it does not go hard. Any excess can be cut off and the surrounding area cleaned with white spirit.

 

[Concerto]

Anyone got any notes on Camper & Nicholson’s practice with balsa core decks?

Same as Westerly or different?

My experience is with a Nich 30. The same advice I provided will be very similar to what Westerly did as the build process was very similar. It does depend on what date your Nich was built and which model. You could also ask on their owners forum (they had a boat at the Southampton Boat Show this year).

 

[sgjfrods]

Westerly always fitted plywood pads for all regular fittings during build and included them for extras like anchor winch or midship cleats.

My prefered sealant is butyl rubber as it is not an adhesive and it does not go hard. Any excess can be cut off and the surrounding area cleaned with white spirit.

I don't suppose you know the typical construction underneath the jib tracks do you?

Would Butyl rubber withstand a scrubbing brush or a jet wash for example?

Many thanks

 

[14K478]

My experience is with a Nich 30. The same advice I provided will be very similar to what Westerly did as the build process was very similar. It does depend on what date your Nich was built and which model. You could also ask on their owners forum (they had a boat at the Southampton Boat Show this year).

MOD 55. 1975. Same (brilliant) designer - Raymond Wall. There is a sort of owners’ group for 55s, but we are very low profile. Surveyors have hammer tested the deck and pronounced it “OK” and the “core sample” from fitting the windlass is good. But I know one of the sisters was notorious for wet balsa in the deck, so I have a sort of nagging worry…

 

[Concerto]

MOD 55. 1975. There is a sort of owners’ group for 55s, but we are very low profile. Surveyors have hammer tested the deck and pronounced it “OK” and the “core sample” from fitting the windlass is good. But I know one of the sisters was notorious for wet balsa in the deck, so I have a sort of nagging worry…

Did she have a screwed teak deck?

 

[Concerto]

I don't suppose you know the typical construction underneath the jib tracks do you?

Would Butyl rubber withstand a scrubbing brush or a jet wash for example?

Many thanks

There is plywood under the genoa tracks to reinforce the deck.

Butyl rubber certainly stands up to a scrubbing brush but I never use a jet wash on my boat as it can cause more problems than the cleaning benefits.

 

[14K478]

Did she have a screwed teak deck?

Good point! I don’t know - some of the JSASTC fleet were built for the MOD and have painted decks - the real “MOD55”s - but others were bought from private owners and were more yachty. At least two had teak over ply decks (since completely rebuilt!)

 

[sgjfrods]

Many thanks for all your inputs!