Chain Plate leaks

[John Gardner]

I have persistent chain plate leaks on the port side of the boat and seem unable to cure them.  I have resealed the passages through the deck several times; I have re-sealed the nearest stanchion; I have removed the "eyebrow" for the last 6 months and sealed the screw holes.  Right now, the forward chain plate, which is the worst leaker, is completely covered at all joining surfaces with modelling clay, and it is still "leaking".  Obviously the water is coming from somewhere else.  Any ideas would be welcome, but the main questions I have are:

The Lewmar ports.  Am I right in thinking that they are clamped into position - there are no bolt holes, screws or other holes into the sides of the cabin top?  If that is the case I feel pretty sure they are not the source of the problem, because the insides of the ports are completely dry.

Does anyone know the construction of the cabin top joint with the deck?  Under the fiber glass is there potentially a crack all the way along between the two?  My fear is that if so it might be acting as a conduit all the way along from the genoa tracks, and that is something I really do not want to undo!

Help!

[jpaulroberts]

Chainplates can leak under different rig load and vibration conditions. Mine leaked. I took all six of them out and totally remounted and rebeded them. They have not leaked since. Putting clay or putty around them will not stop the leaks, just hide or divert them.

My windows do leak a bit and I have seen where the previous owner has tried to stop it buy putting bedding compound around the bottoms of the frames. I am going to take the window frames out and rebed them.

Boats flex from pounding seas, from mast vibration, from temperature changes between different materials, etc. Boats leak and we have to fix them every now and then. Sadly a lot of people try to cover leaks. That just sends the water someplace else.

I do not know of any reason your hull to deck joint should leak unless you are burying you rail a lot. If it is rain or deck spray that is getting in, I'll bet it's your chainplates or window frames.

All the best. Jerry

[Gary Ambrose]

As a lot of good folks have pointed out leakage at the chain plates can come from elsewhere.  I worked very hard to find ours and had rebedded the chain plates and stanchions but still had moisture.  A thin bead of silicone above and around all ports solved the problem.  That was not the permanent fix of course as rebedding the ports was the issue but that quick fix allowed me to know the leak source.  The silicone removes very easily.  Water was traveling from the port leaks to the chainplates.  Not good since that means water moving in the deck core to the chainplates.  But fixed promplty seems to have not only solved the leak, but on inspection the core, where visible at the chainplates is still very firm. No more leaks! And a way to find a leak source.

[Stu Jackson]

See http://www.c34.org/faq-pages/faq-beckson.html for leaky Beckson ports for you folks with boats in the 0 to 300 hull number range.

Also see http://c34.org/bbs/index.php?topic=2629.0 for references to the original C34 homepage for lots of material on older boats.

[Ron Hill]

John : Let me try to answer your main questions:
Lewmar Side ports.  They are clamped into position with screws from the inside screwing into the outside oval ring.  Tighten each one equally and you should be OK.
Deck top to hull connection.  There is an overlap that is caulked from underneath.  A number of owners have reported that they had leaks from uncalled holes in the rub rail holder(underneath the vinyl rub rail).  Seems that the installer drilled a hole to mount the aluminum holder and couldn't go all the way thru(for some reason), so drilled another hole - but didn't caulk the one he didn't use!!  Water comes down the rub rail and shows up in many strange places.
Hope this helps.   

[John Gardner]

Helpful stuff.  Thank you. Just to make sure I'm clear...  For the Lewmar ports my train of thought is that since there is no visible sign of water around the inside of the port, and if there are no fixing holes anywhere that I can't see, (just the big one I look through!) then the ports are not the source of the leak.  In order to get into the deck the water would have to come under the outer bezel to the inside onto/into the wood that I can see, and work its way down to the chain plates from there.  If I understand you right Ron, there are no holes.  But I'll try the silicone round the edge trick anyway.  In a similar vein, modelling clay round the chain plate is in no way permanent, but it's an easy way to make a temporary seal to try prove or disprove it as a leak point.

Regarding the deck joint, my question is about the joint to the sides of the cabin, not to the hull.  I think the core for the cabin top is plywood, and I know the core for the deck is plywood.  I could imagine that during construction a crack is left where the two join.  This could be a conduit for any water that gets in there, such as from the genoa track.

[Roc]

John,
Try running the hose at the chainplates, go below and see if water is leaking from them.  You can try to make a 'moat' with modeling clay around the chainplates.  Fill it up with water.  Go below and wait to see if the water saturates through.  I know when my chainplates were leaking, just washing the boat caused water to show down below, very evident that the drips were coming in from the chainplates.  So if there's a leak, it may not take that long for water to migrate through.

[Ron Hill]

John : As I recall there was a note in a recent Practical Sailor mentioning that silicone does not bond well with stainless!!
I like to use poly sulfide and like to recaulk the chain plates when they are tensioned.  Just make sure that you don't go sailing until the caulk is fully cured.