Upper shroud chainplates: what was Catalina thinking??

[Gene Neill]

I've been pulling all my interior teak out this week, sanding it down and Cetol-ing it. It's lookin' like a million bucks! But in the process, I've come to the sad awareness of how badly rotted the plywood bulkheads are, that the chainplates bolt up to.

Which has me wondering: is there a reason it was done this way? You've basically got a huge slot-shaped hole in the deck, with the plate going through it, that's very prone to leakage (which is a whole nuther question). Directly under that is a piece of cheap, teak-veneer plywood that's very prone to sucking up leakage, and rotting.

And THAT was the best place to secure the upper shrouds??

Both the old and new style C22 are like this. So, there must be something I'm missing, a reason it has stayed this way. Anybody care to ejucate me??

 

[justsomeguy]

It was/is sufficient?

 

[Stu Jackson]

Contrary to popular opinion usually from people who do NOT DIY, chainplates are and should be considered part of regular routine maintenance.

Whether the chainplates were attached to a bulkhead or not, if the chainplates leak, whatever is down below gets wet.

Our C34 doesn't have chainplates connected to any bulkheads. The following CY boats, however, do: C36, C310, C30 and probably more.

And many other builders use(d) that technique.

Fix the leak.

 

[kito]

Mine is an 84 and dry and solid. It was designed for it's purpose. Just keep them sealed and they will last decades.

 

[Gene Neill]

Fix the leak.

Long since done. I saw the water stains on the wood when I bought the boat, and rebedded them without waiting to find out if the leak was fixed yet or not.

Still hoping for an understanding of why it's done this way though.

 

[Stu Jackson]

Still hoping for an understanding of why it's done this way though.

They use the bulkhead to support the load from the shroud. The other way to do it is to have the deck support the load (on smaller boats, and like your other lower shrouds) or to have tie rods go further down the boat and be supported by structural members below.

 

[Jackdaw]

Long since done. I saw the water stains on the wood when I bought the boat, and rebedded them without waiting to find out if the leak was fixed yet or not.

Still hoping for an understanding of why it's done this way though.

As Stu notes, old school. This was a design technique left over the days of wooden boats. It was used by some manufacturers (not all) of early fiberglass boats, and was largely abandoned in most new designs/boats by say 1990. The use of wood as structural material is fiberglass boats does not make a lot of sense.

If the chainplates do not attach directly to the hull, current best practice says they should be connected thru the deck and cabin with SS rods.

 

[Maine Sail]

Still hoping for an understanding of why it's done this way though.

Because tit is cheap..!

How many man hours went into this, vs a few holes drilled in a wood bulkhead...

 

[Gene Neill]

Gotcha. I am now better ejucated than I was yesterday, thanks! I suppose 15,000 boats say plywood is plenty strong enough, if people would just do a little maintenance once in a while.

Now, to find a source of that plywood!

 

[ShotgunSlim]

Hey Dawg, I had the same problems you're finding on my '86 on the starboard side and I found out about that before buying the boat. The whole bottom of the bulkhead was rotten and the chainplate holes were starting to elongate. The PO had no idea about all that since he only owned the boat about 9 months before selling her and never really did anything except buy parts and procrastinate on their replacement. Being a part time wood butcher, I used that knowledge to leverage a small price advantage when it came time to negotiate the sale. I went to my local lumberyard and had them order a 4 x 8 sheet of 1/2" Mahogany plywood for me to play with. Like you, I pulled every piece of wood out of the cabin except the trim around the sink/counter and the port bulkhead and like you, took to it with some Cetol and sandpaper and the results were beautiful. I think I have some pictures here in my online profile if you need some inspiration.

 

[Calif. Ted]

Directly under that is a piece of cheap, teak-veneer plywood

You are about to learn it's not so cheap these days

 

[Gene Neill]

Hey Dawg, I had the same problems you're finding on my '86 on the starboard side and I found out about that before buying the boat. The whole bottom of the bulkhead was rotten and the chainplate holes were starting to elongate. The PO had no idea about all that since he only owned the boat about 9 months before selling her and never really did anything except buy parts and procrastinate on their replacement. Being a part time wood butcher, I used that knowledge to leverage a small price advantage when it came time to negotiate the sale. I went to my local lumberyard and had them order a 4 x 8 sheet of 1/2" Mahogany plywood for me to play with. Like you, I pulled every piece of wood out of the cabin except the trim around the sink/counter and the port bulkhead and like you, took to it with some Cetol and sandpaper and the results were beautiful. I think I have some pictures here in my online profile if you need some inspiration.

The difference is just amazing, isn't it?? It started with my wife asking me to do the two bilge covers ... and you can guess how it went from there. They looked so good, I knew I had to do it all. The only thing I have left at this point is that sink trim you mentioned, and I should have that done by the weekend. I'm also working on a shelf to go along the starboard side, patterned loosely on this design here:

.

 

[ShotgunSlim]

Nice!! I also looked at that idea and then thought about my losing more seating space so if I do anything for storage in that area, I'm thinking about some small mesh hammocks or bags that can be easily moved around the cabin.