Hugh, there's a strong probability that the chainplates leaking are the culprit. It could also be the portlights or stanchions but I would address this problem first as you know for sure it exists. It also sounds like there's a lot of water in there. You should consider pulling all your chainplates and do a thorough inspection of the core in there and do some poking about with a sharp tool to see how solid the core is. You may find voids in which case you will need to investigate further how extensive they are and how to fix them.

If there are no voids I would strongly suggest that you grind the core out in the chainplate openings and fill the resulting area with thickened epoxy. It will seal off the core from any future leaks and prevent core damage.

If the wood in the bulkhead has started to go soft from the water you can stabilize that once it is completely dry. It takes a long time to get it dry, weeks or months. Start by drilling a series of very small holes behind where the chainplate sits, you will need to drill lots of holes to get it dry and ensure full penetration of the epoxy. Then inject one of the epoxies designed to solidify punky wood, such as Git-Rot. It is a messy job but if done right the panel will be stronger than when it was new. If the bulkhead is really badly damaged it can be changed, there are articles here on how to do that. I suggest this is a possiblity with the center chainplate that should be checked into because when we bought our boat, it had a "tiny" leak which we were assured was not significant and that turned out to be a massive understatement. No deck leak is "tiny" on a cored deck.

Given how much of a problem this is with C36's, you might also consider the newer chainplate covers for the center (upper) chainplates. These covers have a raised flange on them to give an added sealant area and keep any ponded water on the deck off the chainplate above the base. They only fit the center (upper) chainplates, at least on the Mk IIs. Catalina didn't tell me that when I ordered 6 of them. I have 4 of the new style covers left over and I'd be happy to give them to anyone who wants them for the cost of shipping.

[QUOTE=bstreet;15622]Given how much of a problem this is with C36's, you might also consider the newer chainplate covers for the center (upper) chainplates. These covers have a raised flange on them to give an added sealant area and keep any ponded water on the deck off the chainplate above the base. They only fit the center (upper) chainplates, at least on the Mk IIs. Catalina didn't tell me that when I ordered 6 of them. I have 4 of the new style covers left over and I'd be happy to give them to anyone who wants them for the cost of shipping.[/QUOTE]

Bud; I'd love to take you up on that, plus offer you a couple of cold refreshments if you ever make it to the we(s)t coast!

Howard, you may have to make good on that, Suz and I are looking at going to BC for 10 days or so next spring, might just show up at your slip with a stein! If you PM me your address I'll get two of them off to you.

Thanks Bud; and if you're going to be in the Nanaimo area let me know beforehand and we can exchange cell ph info!

I replaced my original chain plate covers with the new and improved chain plate covers from Catalina a few days ago. All six covers were a perfect fit for the MKI. I purchased the covers last spring and just got around to replacing them this week. It took me about 20 minutes to replace each chain plate which included cleaning the deck and resealing the cover. I used butyl tape as the sealant and found it to make the task quick and easy. I purchased the tape from this location which was on an earlier C36 post: [URL]http://www.pbase.com/mainecruising/butyl_tape[/URL] The tape sticks to the SS plate and pretty much anything else it touches. It also appears to bond to intself once you touch one piece to anther. I made sure there was ample butyl tape on the bottom of the plate and around the chain plate itself before tightening the covers screw. As you tighten down on the screw the excess butly tape squeezes out making a secure seal. I used a razor blade to trim up the excess making it a clean install.

I returned to the boat today to inspect for leaks. The only hint of a leak is from the front starboard chain plate. I narrowed the leak down to the front bolt. Seeing I need and extra pair of hands below to remove the nut I will take on that task soon. I won't know what I have until I remove the bolt which I am sure will give me another project?

I replaced my chain plate covers this year with 6 that I bought about 3 years ago. They all fit on our Catalina MKII. I assume there is some variation on these parts since others have had fit problems on the lower shrouds.

I bedded with butyl tape. I have used this stuff for years on two boats and never had any subsequent leaks.

I also took the important extra effort to bevel the chain plate and bolt hole openings to further ensure leakage protection for years to come. The how and why is very well presented at [url]http://www.pbase.com/mainecruising/rebedding_hardware[/url]

Hugh, I'm going to try to ship these out Monday, I'll let you know what it costs. As far as finding voids, probably most reliable is a hammer test where you give whatever you are testing a stout whack with a non-metallic hammer, if there's a void you will hear a very different sound. Hard to miss. A fair bit of work because you need to whack it every 6". That might not work on solid but wet core, so you also can use a moisture meter though they can cause problems at times with incorrect readings and variations between boats. I bought one when we were looking for a boat and I now use it just to monitor the deck, I am looking for changes in moisture readings, not absolute values. They can be a bit of black magic in untrained hands though.

I returned to my boat today. After inspecting the forward starboard chain plate I determined the two bolts were leaking. I am guessing the bolts were already semi leaking due to the breakdown of the silicone the PO had used. I also remember using a screw driver to check the tightness of the bolts which must have destroyed what was left of the silicone caulk. The inside top of forward starboard the cabinet was wet as well as the cushion below.

Using a pair of vice grips to hold the nut I was able to remove the two bolts. As with the previous reply by Nile, I used a counter sink bit to bevel the hole and then replaced the bolt using butyl tape wrapped around the threads to seal the hole. After both bolts/holes were replaced with butyl tape I flooded the deck with water. The leak issue was fixed.

I will revisit the remaining 6 bolts at a later date and use the same process to reseal the bolts.

Later in the afternoon I visited a local broker to look at a C36 (1983). While looking the boat over for some future projects I looked in the front starboard cabinet. I found moisture around the two bolts and chain plate as well as old and new water stains on the cabinet wall below the chain plate. It appeared to be leaking in the exact same area as my boat.

It suggest there might be a pattern with the forward starboard chain plate leaking. Seeing it's hidden from view by the cabinet it doesn't become an obvious problem if you can't see it. The other six bolts are in plain sight making it easier to spot the problem...

I am probably the newest member of the C36 leaking chainplate repair club.

Hugh the reason the water ran out when you removed the screw is likely delamination or pressure from a swollen core that is saturated with water. The core is sandwiched between the decking and cabin liner. There are a number of screws the go from the cabin up into the deck and the core that are used for mounting shelving, etc. Water particularly likes to accumulate where the core is sandwiched under the toe rail. You can get water intrusion from deck cracks, bolts going down through the toe rail, from the jib T-track, chainplate bolts but most likely it is the chainplate.

I am refitting my C36 after a number of years of disuse due to health and job issues. My port main chainplate was leaking. This saturated the plywood (11/32nd's by the way according to Catalina's schematics) and ran down to the toerail and then fore and aft to complete the nightmare.

First, borrow or go together with some marina friends and buy a moisture meter. I got mine from Canada, the Rayplex 33 for under $200. It is a must have for any old boat owner especially with the chainplate potential for damaging your deck. [url]http://www.rayplex.com/[/url]

The meter mapped out where the damage started and ended. You have to average the area where it ends due to the sensor size but with a crayon you can map out the good core, questionable core and wet core. I cut an extra 6 inches of decking to make sure I got all of the wet core. The attached shows after the decking was carefully pried off.

I am replacing the coring (after much chiseling, grinding and sanding with new marine plywood and epoxy bonding the old decking back in place. In the offending chainplate design the wood came directly in contact with the chainplate. Design flaw IMHO. I am cutting the new wood core back away from the chainplate enough to accommodate a sealing layer of West G200-Flex epoxy, then sealant and the new Catalina Chainplate covers. Anyone who wants counseling or therapy on doing this repair feel free to email me. I took loads of photos and documented notes from conversations with Catalina Tech Support and a couple of great c36a members who shared their experiences.