Leaks from Hull/Deck Joint - Bavaria 37/2006

[umu]

On a few recent multi-day trips where we were going to windward in quite heavy seas I noticed after about two days some water in the V-Berth, coming down from the vinyl padded wall coverings.
After investigating further I found it is actually entering from the hull/deck joint in the area of the lockers above the berth and then traveling down/back.
Watering the toerail did now show any noticable ingress (like from the screws in the toreail), however when spraying upwards along the outside/hull towards the toreail the water ingress is reproducible - which explains why this was never noticed before, even in major downpours.

Has anybody had a similiar issue and advice how to fix this temporarily (we wont be able to get the boat lifted or to a yard over the next 2-3 months) and long term???

[IslandAlchemy]

Yes. You have to remove the toerail and re-seal the hull/deck seal with Sika.

[Scorcher IV]

Hi Umu,

I have just posted a similar thread, I am getting a leak into my starboard stern cabin. Like you I cannot lift out at the moment but have tried to stop the leak as follows:-

Firstly I have removed the screws holding the toerail down to the deck hull joint along the length of the cabin, injected some marine silicone into the screw holes (filled them), wrapped the top of the screws in butyl tape and screwed them back in. Having removed some of the panels in the lockers I could see and feel that the screws are now coated in silicone, the butyl hopefully seals the heads of the screws.

Next I removed the stanchion base, cleaned off the sealant underneath and re-bedded the base in butyl tape, added butyl around the bolts and bolted it all back together. I think the stanchion base was a big part of my issue but will not know until I return to the boat and check the paper towels left underneath.

The attached sketch shows the layout of teh deck/hull joint on my Bav 37 2006. As far as I can see the only route for water inside is through the screw and bolt holes of the deck fittings, if the glued joint between the deck and hull has failed that will be another level of pain I do not want to contemplate.

Good luck sorting teh leak.

Simon

[artemis]

Hi There

I had the same issue I removed the toe rails and stations and re-bedded it with Arbomeric MP20 Its a lot cheaper that marine sealant's you can get it from Builders merchant's and the primer is Arbo 2650.

Rgds
Mike
Artemis

[sy_Anniina]

If stanchion bases are leaking you most likely also need to upgrade the washers under the deck (between nut and deck) to more substantial backing plates.

The leaking stanchions-topic has been discussed here widely.

BR,

Tommi
s/y Anniina

[umu]

Thank you for your feedback!

I had leaking stanchion bases in the past but fixed those. After long tests I am confident this time it is neither coming from the toerail screws nor from the stanchion bases.
Even after downpours or watering from the top for a long time I have no water on the inside

However when using a hose and spraying upwards along the hull towards the toerail it takes only a few
minutes and water seeps out on the inside of the hull deck joint in two areas.
Initially I noticed this when going to windwards into heavier seas where this area is also continously affected by water.

I can see that in a few areas the toerail is not totally flush with the hull and my guess is water can thus make it to the  hull/deck joint and to the inside. See arrow on attached drawing.

My only idea so far is to fix this temporarily by sealing between the toerail and hull with Silicone (can‘t even buy Sika around here). However I am a bit reluctant to do this because I am afraid this might trap water which currently might get underneath the toerail from the deck and just running off now eventually only being able to escape thru the leaking hull/deck joint, thus making matters potentially worse.

[Scorcher IV]

Hi Umu,

How long have you had the boat and has it ever had any damage in that area. Looking how the deck and hull are assembled in the yard video, they apply the sealing compound then screw the two parts together other than impact damage opening the joint I cannot see how it would fail. You could take off the bow fairlead quite easily to get a better look at the joint.

Simon

[Yngmar]

I had to do this on our boat too, on both sides. The joint was uneven and very poorly caulked, with big gaps where there was just not enough caulking to fill the gaps, so no wonder it leaked. Additionally the original caulking had not adhered well for whatever reason and when removing it, long sections just pulled out (which made the job easier).

I raked out enough to have room for new sealant, cleaned up and degreased with acetone and then recaulked properly (using MS Polymer adhesive sealant). It took several cartridges per side.

Luckily on the 40 Ocean the joint is accessible after just removing the teak rubrail from the sides (the one with the stainless strip running the length of the boat).

[umu]

Hi Scorcher,
no impact or crash, at least the last 5 years we own the boat.
In the meantime I took the cover panels in the front cabin lockers off and inspected the length of the joint. Indeed as written by Yngmar the joint is very inconsistently filled with caulking. Some areas it squeezed out nicely even to the inside, some areas I can poke for at least 1cm from the inside of the rim before touching caulking.
I sealed the toerail to hull joint on the outside with silicone as an interim (terrible botch) and this seems to have stopped the leaking.
Why this did not turn out to be an issue before I have no idea, maybe it was always slightly leaking but dried out and only when beating to windward for almost a week in a row it was so much that it eventually found its way to the mattresses in the V-berth.

[pk]

Hi umu,

I have exactly the same issue on my 2005 Bavaria 37 which is water in the V-Berth coming down from the vinyl padded wall coverings - in my case only on starbord. Just as you described there is no water in the V-berth even when watering the deck in the marina, there is just water entering when sailing in heavy seas. Thanks so much for sharing this, I guess it would have probably taken me at least one more summer to find out it might have something to do with the poor quality of the hull deck joint and with water entering the gap between the rail and the hull.

I have two questions for those of you who have already done the job, removed the toerail and renewed the sealant sitting in the hull deck joint.

1. After taking off the toerail on the Bavaria 37, is the elastic glue / sealant at the hull/deck joint accessible at all? Can it be removed easily in terms of space and access? On the drawing which was shared by Scorcher IV it looks as if the sealant sits underneath the deck, obviously, and if one would have to "lift up" the deck (which is not possible) in order to get access to the poor sealant.

2. What about the laminate of the deck which was affected by the water entering from outside? Does it not need any treatment or repair since is might be wet? How can I tell if this is problem?

Also, I am a little reluctant to romove the whole toerail (on both sides) since I might run the risk of creating new problems ("verschlimmbessern" as we say in German) with leaking stanchion bases or leaking screws in the toe rail - they are now all totally water proof and not leaking at all. This makes me wonder if it is not a better idea to just seal the toerail to hull joint on the outside which you, umu did as well.

Thanks in advance!

Phillip

[Lauramartin]

Hi all
I had a leak that was tracking down the hull and into the starboard aft closet from the deck-hull joint/toerail. It was worse when sailing. Although the deck is sealed down to the hull in the manufacturing there are cutouts on the deck at the bulkheads so that the deck can be lifted onto the hull. At these sites there is nothing for the screw on the toerail to securely hold into so it leaks. We fiberglassed over the cutout and then used bolts with washers to hold the toerail. I check the other cutouts at all bulkheads areas to try to catch any leak early.