Bedding chainplates - quick and dirty way

brak · #1 (**permalink**) 05-10-2008

Ok, so after about a year of ownership (and a lot more time since last rebedding) one of the chainplates started to leak. Its a tiny leak to be sure, if I didn't check them weekly, I would not have noticed. Anyway, I need to rebed this one chainplate. The limitation is that I can't remove the cover plate (or whatever it is called) on deck, unless I disconnect and remove a turnbuckle - and doing anything to my rigging is not in plans right this second. So, I can lift the face plate about an inch or two, and clean whatever I can get to that way. There is almost no clearance between the chainplate and the deck on 3 out of 4 sides - I can't even slide a blade of a knife in there, so it will end up being fairly superficial bedding.

Here is the issue. The PO used silicone as a sealant (everywhere). On the one hand, evidently it worked well - considering how other chainplates are holding up. On the other - I just don't like silicon, I'd rather use polyurethane sealant. But with the limited access I am probably not going to be able to remove silicone completely. So, is it worth using silicone again (on a premise that it would stick better to any potential remnants of old silicone) or use polyurethane (probably 4200, or whatever local West Marine carries)?

This is all temporary anyway - the rig will probably come down in fall and I can do a better job rebedding all chainplates then, but I'd like to do what works for now.

lharmon · #2 (**permalink**) 05-10-2008

You should be able to loosen just the one shroud. If you are especially cautious you could tie off a haylard on that side. Just mark the turnbuckle so you get it tensioned the same. Then everything can come off, you can dig it out and put it back together. I'd say 30 - 45 minute job.

Great catch spotting the leak so fast.

camaraderie · #3 (**permalink**) 05-10-2008

Ditto Lharmon...it ain't hard and it ain't worth doing any other way.

sailingdog · #4 (**permalink**) 05-10-2008

Brak-

Don't do a half-@ssed job on it... take the cover plate off, even if it means using a halyard to hold the mast up for a day or two.

Seal at the top...don't seal it on the bottom, since you want to know when it is leaking, rather than finding it by having the chainplate support areas all rot out.

NOLAsailing · #5 (**permalink**) 05-10-2008

Just lift the cover plate up and secure it an inch or so off the deck with tape or a bit of messenger line. Silicone is tenacious, so spend time carefully scraping it off. Then, the most important part - DO NOT USE 4200.

It's primarily an adhesive, not a sealant. Use 3M 101, or Sikaflex, or another sealant designed for this type of application.

brak · #6 (**permalink**) 05-10-2008

I never planned to seal at the bottom - I don't do that

I am pretty particular when it comes to boats leaking from above (i.e. I like my boat dry).

The choice was to lift the cover plate a bit, clean that way and seal or remove it completely. I actually removed the shroud (it was a rear lower, so I didn't need anything to balance it out, that's the beauty of a short rig).

My main concern was using silicone for bedding. I thought about this for a bit and decided not to use it - I just don't think silicone is an appropriate marine sealant. So I cleaned the thing as best I could and then used 3M 4000. This is the first time i tried it - it is supposedly new sealant from 3M, presumably it has good UV resistance and remains flexible. I guess we'll get to see how well it works.

I like Sikaflex but they sell it in these large tubes (of which I do have several) and I just didn't feel like dealing with one of those and a sealant gun for a tiny chainplate.

Freesail99 · #7 (**permalink**) 05-10-2008

What about Boat life? It remains flexable and also seals well. There are different kinds for different jobs.

BoatLife - For the Life of Your Boat

brak · #8 (**permalink**) 05-10-2008

I never tried Boatlife products either, to be honest. I am pretty happy with Sikaflex for most jobs, the only problem as I mentioned is container size (and it does become yellow under sunlight). So, I figured there is no harm in trying this new 3m thing - it can't be too bad, and in the worst case I'll replace it when I rebed all the chainplates later.

NOLAsailing · #9 (**permalink**) 05-11-2008

Regarding Boatlife: The LifeSeal product is a hybrid sealant with silicone. Use it on plastic parts that a polysulphide might damage.

LifeCalk (yes, that's how they spell it) is a polysulphide. It works OK, but I won't touch the stuff as it will turn yellow, then brown within a couple months.

brak · #10 (**permalink**) 05-11-2008

I tried lifecalk today. I think this is the first and list time I do so. It was very dense, hard to work with, impossible to shape and a bear to clean up. It better be a perfect sealant for the next 100 years or so, considering how difficult it was to work with. The rest of the tube went into trash right away. I am gonna stick with Sikaflex or 3m, I think.

Incidentally, we have torrential rain here and two more chainplates feel moist (I may be paranoid about that, there is no actual water) - anyway, I'll probably rebed the rest in the next few weeks.

I do, however, have one leak from above in the boat - entry for mast wires. The current fitting is a joke - more of conduit for water. I've been trying to get a "swan neck" (kinda an overturned snorkel) to install for a year now. It seems like a trivial fitting, but noone sells it anywhere (except Hallberg Rassy parts, and I bought that one - but it's a size of a dorade

, probably works best for those 60 foot yachts). Anyone has a pointer to a piece of 180 degree elbow with a flange on it? I'll pay anything for it, seriously.