howdy,
i've contacted a SS fabricator to build some SS plate to go over the attachment points for my side shrouds and wanted to get any input as to if using this plates would be helpful in a) distributing the load and 2) helping prevent water intrusion. I had contacted Catalina for chain-plate replacements but the cost was going to be prohibitive. I have a Mark I on so it doesn't use the ball and socket connector but rather the old style. my idea was to replace the small covers on the side shrouds with a 1/4 thick plate that would go over the shaft and to match up the holes that the current bolt wash combination connects to the underside of the chain-plate, a mock up drawing is attached(i hope)
Mike Hogan
s/v Ciscocat #226
Mark I XP25, std rig
Looks like a good idea.
There are bigger gains to be made by removing the plywood core for a few inches around this area and replacing with glass, but the two in conjunction would be great.
Jason V
Vancouver, BC, Canada
Mike.
If talking about the small covers you mention covering the chain plates. To me there is no advantage structurely to making them bigger. Mine as basically covering the gap in the decking. I remove them every other year and rebed each one . If you are fighting a issue of having a wet deck in that area ,then as numie states. Your better off getting into the decking and fixing that correctly.
Randy Sherwood
Mutualfun 1990 # 1057
T/R W/K M35a
Home. Charlotte, Mi.
Boat. St Augustine,Fl.
Mike,
I think I have to agree with Randy. The covers are more decorative, and help somewhat to hold the sealant in place. The "work" is being done by the rod or chainplate that attaches below the deck. If you have a leaking chainplate, the best cure is to completely remove the chainplate, remove any wet core, and fill with thickened epoxy. Cut new hole, bevel the edges, replace the chainplate, and re-caulk. Shine up the old cover plate and replace. Should be leak-free for at least a couple of years.
Tom Sokoloski
C36/375IA Past Commodore
Noank, CT
Thanks for the input and i may not try and get the parts fabricated i haven't decided yet. And you are right to point out if there is a problem with water intrusion that any damage should be corrected and the method that is purposed is a good one. But given all the above and the comments the question i have to ask is that if the design of the attachment is so great then why did Catalina change to something along the lines that I've suggested on there new model boats. seems to me that you are asking a lot of two bolts and the pressure that generates in a somewhat limited area. I'm not a marine engineer or designer but it seems that if you can spread the load over a wider area it is a good thing.
FWIW
Mike Hogan
s/v Ciscocat #226
Mark I XP25, std rig
If the stainless steel rods from the chainplates to the hull structure are properly adjusted there shouldn't be much if any load going into the deck at the chainplates. Maybe the Mk I's use a different arrangement than the later boats though.
Mike.
The only thing that the 10-24 bolts do is to hold the cover down. There is no load bearing issues with the covers. I have sailed with out the covers to see if the chain plates were moving.
Randy Sherwood
Mutualfun 1990 # 1057
T/R W/K M35a
Home. Charlotte, Mi.
Boat. St Augustine,Fl.
I guess once again didn't make myself very clear. The intention was to replace the the covers that were held down by the screws but to fabricate a piece that would fit over the fittings that protrude out of the deck from the chain plate attachment on the underside of the deck and provide a cover for the 3/8(?) bolts that hold them to the deck. Obviously the current covers provide nothing to the set up other than, well a cover. Where as the fabricated replacements would provide an attachment to the through bolts that ARE holding the chain plates in place
Mike Hogan
s/v Ciscocat #226
Mark I XP25, std rig
Mike,
I dug around on an old computer, and found the attached factory MkI drawings. I honestly can't see any advantage of adding a larger cover plate on the outside of the deck. All of the chainplate/shroud loads should be taken up by the tie-rods, and not by the deck.
Tom Sokoloski
C36/375IA Past Commodore
Noank, CT
Ok now I think I understand what your thinking Mike. The plate you have made will slip over the chain plate from the underside and you will redrill 2 new thru holes with a like plate on the top side. Thus thinking that this will spread the load out as the plate is bigger. If I am thinking right here now in what your thinking of doing it would would. But the key thing is to really figure out how wet the core is. If your just trying to bide time that would do it but if your seeing a raised deck around the chain plates now it will only get worse in time. Being in industrial maintenance all my life I am one that wants it done right and not having to think when it will fail. Just food for thought. Good luck and happy sailing
Randy Sherwood
Mutualfun 1990 # 1057
T/R W/K M35a
Home. Charlotte, Mi.
Boat. St Augustine,Fl.