Hello
I have a leak from the port U-bolt. The water goes into the chart table. Since 5 years, I have taken off 3 times the U-bolt and I have put on with Sikaflex sealant.That is waterproof for the summer, but 6 months later, the water comes again .
I have heard about Butyl , rubber based sealant ( arbomast br but not available in France). Have you an experience with this sealant for the U-bolt plate.
Thanks for the answers.
Best regards
Pascal Claeyssens
Maruli P325/27

Hi Pascal

Are you talking about the chain plate for holding the shrouds. (u-bolt??)

Regards

Barry Tiernan

Sulito 39
Poole

Hi Barry,
Thanks for your answer. It is for the chain plate for holding shrouds upon the deck. I have found the word U bolt in a dictionary, but I suppose it isn't a good one.
Best regards
Pascal ( from French Britanny)

Hi Pascal

I have the same problem. I started a thread about chainplates in October this year and this is a common problem

The design is an issue as the cover is welded and part of the chainplate. So if there is any movement of the chainplate the cover lifts from the deck and allows water to seep in to the bulkhead/chart table.

In my case the holes in the bulkhead have elongated and pulled up a few mm which shows as a gap on the chainplate cover. If you look at the pictures from my posts on chainplate problems you will see,

I have just made stainless sleeves to go into the bulkhead. When the wind is light I will remove the chainplate and re-bore the holes. I will resin in the stainless steel sleeves. I will then get the chainplate back down flush with the deck.

I suspect that there will continue to be a pull on the chainplate cover from...

1. The angle of the shrouds pulling up
2. In hot weather the mast will expand greater than the shrouds and this will probably try to pull the chainplate up again

Unfortunately as the chainplate cover is welded to the chainplate it is hard to keep this flush with the deck.
I will use a flexible marine sealant as hard glues as Sikaflex will just crack. I suspect if you try to blot the chainplate down to the deck, the upward pull could crack the deck, not a good idea

I will send photos when I complete the work
Although given the angle of the shrouds to the chainplate I suspect this will be an ongoing issue and will need regular topping up with sealant.

A lot of other members have the same problem

Nice to talk to you

Regards

Barry Tiernan
Sulito 39

thank for this answer
there are four screws to join the plate to the deck,but ,of course they move also. The Boat will be ashore for the winter next week. I will take off the chain plate again with the mainsail halyard hooked on the toes rails. And I will try to do that you have done with an epoxy filler but I must wait the spring to have a good temperature. Now our boat is 25 years old.
Best regards
Pascal
Maruli P325/27

Hi Pascal

When we took one chainplate out out of our boat because it was leaking, we found that the slot in the deck was much bigger than it needed to be.
Filling this slot with epoxy filler so that there was just room for the chainplate to go through left a much bigger area under the deck plate to apply a sealant. We used Arbokol 1000 as a sealant and it is still fine two years later.

Martin
P335/50 Tringa

Many thanks for your good advices.
Pascal

Hi Pascal
I have had a similar problem with my 275 shroud plate. I tried many sealants including Sikaflex etc over the years. I have found that just digging out the sealant around the plate and replacing with very cheap bathroom sealant works well for a couple of years. A very inexpensive and effective solution.

Bon chance

Tim Reeder

Hi Tim,
Thanks for your help. Somebody tell me about car windows sealant, but I think that will stick too hard the deck and the deck will work upway badly.
I shall try the butyl sealant and I shall look the bulkhead holes. Maybe I will have to fill the holes with an epoxy sealant and will drll new holes 2 or 3 mm more lower.
Sorry for my poor English language.
Best regards
Pascal
Maruli P325/27

If the external plate is separate from the chainplate tang, as it should be, remove it and clean up underneath it and then refit the cover with Sikaflex or similar but do not screw it down, only loosely insert the four screws to hold it in position and allow the sikaflx to set with about 3mm of Sikaflex below the plate, Once its s set, screw down the plate and now the Sikaflex will be under constant compression and should not leak. The problem is caused by screwing the plate down tight in the first place, and the Sikaflex is then squeezed out with only a thin film holding the plate in place. Any movement of the hull relative to the chainplate will result in the Sikaflex bond being broken and allowing water ingress.

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Hi Martin
Thanks for your help.
The external plate is not separate from the chainplate tang; but it is a good idea to put the bulkhead bolts not too early and waiting the sikaflex (sikaLastomer 710 TX white) begins to be a little hard before to press the external plate to put the bulkhead bolts in place.
Best regards
Pascal Claeyssens

Hi Pascal, that's annoying if the plate is not separate ( I seem to recall it is on the Parker 27) but if you have enough space, it's still worth while leaving the Sikaflex to set completely before tightening down the screws. If you screw them down tight before the sealant has set, you will not have achieved anything. Think about the potential movement of the chainplate and how that will impact on the sealant. Some people use a form of non-setting marine mastic but I have not found one that I would trust in such a critical area, on this side of the pond. They do have one in the USA but it's not available over here and when I looked into buying some and having it sent over, the shipping cost was more than twice the value of the mastic itself and made it uneconomic. I do use a German brand for beneath my winches, and jammers and other deck gear that seems to work very well so far but in those instances, I counter sink the bolt holes beneath the fittings so as to allow a clump of mastic to fill the countersunk space and allow for movement. It might work to do the same around the chainplate slot so as to have a larger lump of sealant to fill the void and thus have less chance of it being ruptured. I can't think of the name of the American butyl mastic at the moment, but apparently its success is largely due to its extreme 'stickiness' even after it has been in place for years.

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Heretical thought here, but have you checked the rig tension? There is a compromise between powering to windward against closing the heads door. I slacked my rig tension slightly this winter and have not had any (rain) water coming down through the chain plates ...
I too have used Sikaflex, and I think I'm just resigned to digging out the old and putting in new, but I might try butyl next time.

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Hi Pascal


Sunday 10th July
I am currently in the marina in Lezardrieux, almost beside you

I have an engine problem with a small oil leak which I cannot trace

Seems worse when in wavey seas


Do you know of a local engineer who might look at it

I can be called on 0044 (0) 7488328212


Regards

Barry Tiernan

Sulito 39