Lower shroud Chainplate replacement

Moody Buccaneer · Jan 6, 2010

captnron said:
Hi to all members,

I'm brand new to the group. I have a 1980 C30 MarkII of which I,ve owned for 20 yrs. I work in the engineering field and over the years have done many upgrades / modifications & fixes to the boat. I now know every bolt & nut. You name it I've done it.

In the future if anyone has a post, I will see if I can add some input. I've had conversations with the big man himself, Frank Butler who is still going strong.

MY QUESTION:
I am in the middle of a full topside re-paint job. Removed every thru-deck fitting. I had a bad smelted chainplate stud (port aft lower chain plate). I am searching for a replacement as Catalina now has a bail type of which the mounting hole spacing is different (waiting for a drawing from Catalina). This will cost some doe to have refabricated, so I am appealing to someone who may know where I can get one.

Thanks for reading.......

Captnron

The lower shroud chainplates on C30s went through 3 versions that I know of. The original boats had 3/8" studs through the deck. Ver 2.0 was an increase in diameter to 1/2" and the addition of a anti-rotation plate with two self-tapping screws. Ver 3.0 was a U-Bolt.

The backing plates for the lower chainplates on the early boats are marginal also. I went from the flat plates (which had deformed over the years) to a section of angle sized so the flange bearing on the deck has 25% more area, and the angle acts as a beam to spread the load. I also decored the deck in that area and created a solid glass/epoxy pad. The next step will be to upgrade the knees aft and to engineer knees forward or tie the chainplates to the hull rather than the deck.

The U-Bolt "upgrade" can use off the shelf parts, and I suspect that is why Catalina made the change. I'm not a huge fan of the point loading that this setup creates between the clevis pin and the U-bolt, but I haven't seen it become a point of failure either.

My choice would be to get 1/2" rigging studs with 3/8" eyes and have the an anti-rotation collar welded on then trim the stud to length. That would be more elegant solution than the U-Bolts from an engineering point of view.

Since you have the deck stripped anyway, why not just go with the latest bits and upgrade all 4?

While you are at it, I suggest going from 3/16 to 7/32 wire for the lowers. 3/16 is marginal even in 302 SS, if 316 SS wire is used the lowers are too small.

Randy

Moody Buccaneer · Jan 8, 2010

captnron said:
Moody,

About the rigging & sizing, I went larger years ago. I didn't get a warm fuzzy feeling with the 3/16" wire either.
Thanks again for the feedback.........
captnron

Glad to help. I did some time as a rigger for whatever that's worth ...

Randy

Bad Obsession · Jan 11, 2010

One company to talk to is www.catalinadirect.com when you are looking for Catalina Parts. They have a lot of parts and also can steer you in the right direction if you need to get a part that they don't have.

One quick point of clarification.....Catalina had three different versions of the 30s.

MKI ran from 1975-1986
MKII ran from September 1986 to 1993
MKIII ran from 1994 until they stopped production.

Your Catalina 30 would be MKI. Here is a link to good info: http://www.catalina30.com/C30Yacht/C30Yacht.htm

Bad Obsession · Jan 12, 2010

The nice thing about owning an older Catalina is that they are still in business. That means that parts are easier to come by and you still have support of the company in some regards.

Another nice thing is that Catalina 30s are nice boats. They were put together rather well and they were a VERY popular boat. Being that they were very popular you can check some places that sell used parts from sailboats that have been salvaged and sometimes come up with what is there.

All of this being said.....if the original system that Catalina had lasted all of these years, I wouldn't worry about replacing the old system with a similar system. God forbid you have to replace the parts again in another 20-30 years! LOL

Alchemist · Jan 21, 2010

One minor point, captnron, If you truely have a 1980 C-30, you have a Mark I boat. The Mark II boats started with the 1987 model year. You can easily tell by either the HIN or more easily by looking at the boat. If the cockpit is "T" shaped, the boat is Mark II or (unlikely) Mark III. If the cockpit is a straight line, your boat is a Mark I.

There are other differences (the size of the companionway hatch, an arched or level traveler, etc), but the cockpit shape is the easiest to see.

Steve
Alchemist C-30T #4764 ('87 Mark II)
Alchemist C-320 #909
Alchemist C-380T #71

Lower shroud Chainplate replacement

Anonymous 121765

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Moody Buccaneer

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Anonymous 121765

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Moody Buccaneer

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Bad Obsession

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Anonymous 121765

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Bad Obsession

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Anonymous 121765

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Alchemist

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