Chain Plates and rust stains

[davidbht]

hi there, I'm a new member here in the forum. I own a 2010 Jeanneau 53.

Since winter arrived and the rain my chain plates have been getting lots of rust stains coming out of the bottom off them. The rain seems to run down the shrouds, fill the ponds at the bottom of the fitting and then as it has no way of releasing the water I'm guessing it just seeps out under the fitting rusting the studs that hold the fitting to the deck. I know this fitting is used by other Jeanneau designs too so somebody must have addressed this before.

I want to know how other boats deal with this and/or are mine missing a seal somewhere to stop the water pooling in the first place?  I did see a previous post (https://jeanneau.proboards.com/thread/878/so36i-leaking-shrouds-deck-fitting) on how to remove the fittings and therefore what they look like but it didn't address my particular question. Mine are not leaking internally.   Any help greatly appreciated.

[Mistroma]

I think it's pretty common and I get it on my 42DS with same type of fittings. I usually dab some fairly strong, hot oxalic acid solution around the base. About 10% strength at about 30C will work very quickly. Oxalic works slowly at low temperatures and I think reaction speed drops off a cliff below 10C.

It will bleach your teak deck if you let it run down on to the deck. I usually wet the deck pretty well below the fitting and rinse off carefully a couple of times when waiting for the Oxalic to work.

Oxalic will lighten the teak a bit if you leave it soaking into the deck. You'd get light coloured tracks if you let it trickle over a dry deck. No real problem if the deck is already wet and you keep any run-off watered down.

I usually apply the oxalic with a very small brush to just wet the area around the fitting. The staining still returns in a couple of months and I haven't found a long term solution.

[davidbht]

Thanks Mistroma.  I was really hoping to find out that there was something missing on mine that would normally stop the salt or fresh rain water pooling against the stainless shroud fittings. Seems an odd design and I was worried it would corrode the stainless.  Anyway, thanks again and I will clean off the stain.

[fimacca]

Assuming the internal is stainless ! ! You would think.......
It is likely to just be cosmetic. i would check when the mast was last down, and ensure i had a look inside the next time it was to see what is going on inside there. Not urgent.

[fimacca]

I have the same issue with toerail fittings i can't get to. They seep after a while and stain the hull gelcoat in 3 places..
I use acid to clean every couple of months .

[davidbht]

thanks Fimacca, that is reassuring to hear.  I had the mast down last year but this was completely overlooked at the time as we just had all the shrouds replaced, mainly for insurance purposes.  Hopefully won't be removing it again any time soon and it doesn't sound like I need to. Phew!