Chain Plates/for CSY and Other Great Cruising Boats worth Upgrading, Including Chain Plate Fabrication thoughts. part 1

It would be wonderful if everything lasted forever but when dealing with boats, I think it is fair to say, "that is not true".

If any of us went out and bought a 1977-1981 Buick or Cadillac, we wouldn't think of taking it out on the road and pushing it to 80 or 100 mph with the original old tires on it, would we? Stainless steel, used for components such as rigging wire, chain plates, and most bolts aboard, is somewhat like rubber, in that it can and does degrade; rubber via sunlight, stainless steel via water/deoxygenated water. It doesn't mater if your eyes spot the fine cracks, the wetted material degenerates.

Rust on an interior chain plate, is a sign of water intrusion through or around the cap rail. It's difficult to determine the extent of damage by the rusting discoloration of the surface. It is known that water has seeped into the hulls around these plates on most boats. If the discoloration is there, that is the proof. After 30 years, it seems advisable to remove and replace them, just as one would do with old tires. The CSY is lucky to have reasonable accessability to the plates, so this project makes the CSY's lifespan extendable more than many or most boats out there.

Rigging wires have a life of about 10 years or a circumnavigation due to the same processes of wetting and stress loading. Why would it be reasonable to think other stainless steel under similar loads or conditions would be different? (I don't know about yours, but my boat will be 31 next month.)

I only became suspect of stainless in the mid 90's and somewhat must thank the CSY Topica list for allowing the subject to get specific, linking the problem to chain plates. Years have passed and much has occurred to confirm that 'we' the owners of this quality sailboat, need to be aware of all the components that contribute to the safety of those who travel on or in it. As I have just mentioned, we would not think of driving a car on old cracked tires, so why would we consider our boats impervious to degradation of important parts. (rigging wires 10 years-chain plates and their bolts... 30???) This is NOT a CSY problem. It IS a boat problem...All boats. http://www.amarinesurveyor.com/chainplate.htm  We are lucky though that as a group, we have discussed it and doing something about it. Many vessels do not have the advantage of our history of discussion/repair solutions, so we are ahead of the pack and safer for it. For some boat brands, this might not be a doable project so they ignore it. Those boats will soon be worthless.


Do not loose the concept that surveyors will not always pick up even, 'visable' problems. They sometimes(and I think I am being kind)seem to not speak of problems that will 'kill the deal'. They are limited to 'viewing' and cannot disassemble anything in their survey, so not uncovering all defects is the reasonable outcome. Even if you ask specific questions and 'get it in writing...' you should trust that Father Time has done his thing and CYA in budgeting for repairs and replacements.


I "Chose" to remove my chainplates before there was a problem. My personal solution was to me, a CSY 44 UPGRADE. After seeing a great chain plate design in Steve Dashew's Cruising Encyclopedia, page 582, I modified their concept a bit to adapt it to the 44' CSY hull and had 10 of them made. Cutters need 6, ketches need 10. (I now use 12 to enable me to rig the mizzen independently from the main without using a triadic stay- by adding forward intermediate stays from the mizzen instead). So far, 6-12 sets of circular plates have been made and installed on CSY 44's. Wide grip, easy fabrication(identical plates) and simple installation and external for many reasons.

Bedding (original) around INTERNAL chain plate was poor. Gap shown here, of 1/4" x 1.5", allowed water to seap below decks. Rust stains on 52oo shows poor bonding and a place that water stagnated.

Photos included here are of the original CSY Triangular plates and are offered only to explain and show the 'obvious' problems. Stainless steel does not last forever and certainly does not 'IF' it is subjected to an Oxygen deprived environment, as "in a trapped area" below the teak cap rail. The bedding of the cap rail was done in such a way as to allow water to get below the cap rail and then run down hill to any opening into the hull, sometimes allowing water to drain to lockers or chain plates.

CSY chose to use 'Internal' chain plates. The chain plate then needs to have it's tang pass through the hull at deck level to attach to the rigging turnbuckles. It is at this point that caulking of some kind is needed and so doing, creates an area to entrap water. Even if only a drop or two, it will stagnate and become oxygen starved, eventually leading to crevise corrosion and stainless steel failure.



The main failure point seems to me to be the first hole below cap rail level and also the cap shroud the most common failure plate.

Failures seem to occur at or near this upper bolt hole as it is the weakest point, due to limits of material mass or weld, subjected to water degradation; then, stress from the rig. The 2" tang, is drilled for the 1/2" top mounting bolt; leaving (2) 3/4" segments of 3/8" stainless, just under the cap rail to get wet and develop 'crevice corrosion'. Add 30 years to the damp environment and rigging stresses and you get.........?

This 2" (now 1.5")drilled tang, is the weakest point of the chain plate. It's subject to crevice corrosion/and stress/it's bolt can be loosened by rigging pressure pulling it's top bolt's flat head inward thru the glass(poor fiberglass support). CSY's design of spreading the chain plate load over 5 lower bolts and only one for the top was going in the right direction in my opinion by spreading the grip over a wide area of glass, but the top bolt is being pulled inward esp. on the forward and aft lowers, which makes it subject to loosening it's grip on the hull and also allowing the upper seal to leak due to movement. That movement will eventually allow water to creep below. An external chain plate would not have had this problem and I opted for this as a fix for my boat.
The load on the "Tang" for the forward and aft lowers, is inward towards mast. The original flat head bolt up near the cap rail and under the 2" teak strip below the cap rail, gets pulled into hull at forward and aft lowers. This load can potentially allow enough movement to break a seal as the tang of the chain plate goes through to the rigs turnbuckle.

Some drawings and photos will be offered on alternative ideas demonstated by owners to aleviate the potential problem and make the chain plates 'Inspectable'.

Do NOT feel that the problem is a "CSY ONLY" problem. Aging stainless steel is a problem that ALL boats share. However, many CSY owners have addressed the issue and have solutions! Chain Plates: part 2 will cover some of them. Even after 30 years, a few projects will bring a rebuildable boat up to snuff.

For your interest: A few months ago I received an email from the editor of PACIFIC YACHTING/boating in the PACIFIC NORTHWEST, regarding my photos of CSY stainless chain plates and bolts . They did a decent write up on the faults of Stainless Steel in the marine environment and used a few of my photos. The bottom line is not my photos, but that good magazines are addressing problems that "All boats of our vintage need to address. Deterioration of metals is a subject for required reading on ALL boats. "WE" are ahead of the others in discussion of solutions!

Chain Plates/ CSY and for other Great Cruising boats worth upgrading: part 2

First to consider if changing out Chain Plates is whether to just replace the originals with the exact same design, or to rethink the pros and cons to see if there might be something better.

A CSY modification like this has been done by a number of owners; externally mounted, not internal, 1/2" plate not 3/8", wide 4" tang not 2", 316 polished/highly corrosive resistant stainless steel/more bolts(8 not 6)/countersunk to eliminate moisture trapping or line snagging, wider footprint gripping the hull, moreso than original 5 bolt base/not less.


Some have replaced the original "Internal" plates and tried to keep them bedded properly. One, has tried to use a superior stainless steel (duplex) and make a one piece replacement rather than a weldment, yet stay with internal mounting. The replacement of chain plates brings up the question of pro's and con's of either Internal or External plates. Internal plates can be removed and a shop can make up 'exact' replacements(each plate tho, will have different angles) plus all the original problems of potential leaks and crevice corrosion/inaccessible inspection through deck/cap rail material. External plates are one piece cutouts and therefore identical to each other; only afterwards are the plates tangs bent inward at the appropriate fore or aft angle needed to align with the stay or shroud. Internal plates have been a weldment but an exit slot might need to be modified if New Plates are cut from one piece of stainless steel or thicker. External need to be better looking, so polishing manually or electro-polishing is the norm, and both measures highly reduces degradation or even discoloration later.

10" circular plate with "Double Tang", mounted above original rub rail/shown on pilothouse ketch. (a tang wide enough for 2 attachment holes, allow adding a shackle for an extra attachment point (when needed) + extra beef in the tang area ) click on photo for better view

Do not forget, that a 33' CSY and a 44' have different size plates, so the amount of S.S. might be double on the bigger boat. Also if you go From a thinner plate to a thicker plate....again you are using more Stainless Steel and it's sold by the pound. IF you are going to mount your plate where you can see it...you probably want it to shine. That will cost some in time or dollars for the labor required. Manual polishing is beautiful and worthy of time and effort, but so is Electro Polishing, as it also protects the surface from rusting. Manual polishing and electro polishing combined, is even better!  A no brainer!

VERTICAL STRAPS used on this CSY 37 looks traditional but round would look great too and have more plate and bolts. Skinny straps have a history of breaking so why go there?


It should be noted that Peter Stolken, ex floor manager of the CSY plant, later on-added external chain plates-to his own prototype CSY pilothouse. His vertical straps are common for external chain plates on wooden boats and the look agrees with traditional aesthetics drawn by Peter Schmitt for the CSY.



On wooden boats, vertical straps are tied into the vessels planks. Fiberglass boats can use the older aesthetic or build plates tied into the hull horizontally (as CSY plates do to use the support structure of the hull's glasswork.)




Peter's "Independence"(above), a custom/one off pilothouse has retrofitted external vertical chain plates. Photo by David Kummerel. click to enlarge any photo







A 4" tang on another design offers strength plus original 6 bolts.  Machine work by JTR/Gulfport, Fl.

After learning of possible chain plate problems in the late 90's, I started to research how other boats were handling the design issue. Steve Dashew's circular design for his Deerfoot Yacht chain plates looked good to me. (It's on page 582 of his Cruising Encyclopedia.) CSY had used a 1/4" triangular base with 5 bolts and one above, welded to a vertical 3/8" piece of flat bar which became the tang above deck. I took Dashew's circle idea, to make a 10"diameter with 4" tang, cut out of one piece of 1/2" thick, 316L stainless steel, mounted externally. One piece/no welds or it's possible crevice corrosion/ thicker material/ highly polished for less corrosion/more bolts-8 vs.6/ countersunk for less chance of crevice corrosion of the attachment bolts, yet inspectable and accessible. The 10"diameter will clear all 44' CSY's. In every aspect, more rather than less than original.

Above:
External 10" plate mounted before new external high rub rail was added. The teak cap rail is removed here BUT, that is not a part of this chain plate job!
A small amount of the original teak cap rail can and should get cut away, to allow the external plate tang to lie flush against the fiberglass of the hull.

S.V.BEAUJOLAIS replaced chain plates in Panama.  Rick Heim of Gulfport Machine, St. Pete, Fl. made and shipped them. Work was done dockside, with Roger and a local worker taking on the task.  Looks good huh?  Roger admits a little extra time later on will be needed to make things bristol again, but I think they did a fine job.

I designed these circular plates for 'my' boat, but offer photos and text for others to investigate. As you can see, the plate fits 'properly'.



-CSY original chain plates were internally mounted and their tangs penetrated the cap rail. This left the tang encapsulated through fiberglass and teak for about 2" and could not be checked for crevice corrosion down in that area.

 






Drawing of plate (above).. note upper 2 holes were slightly lowered so that nuts and washers could be easily installed-inside the hull- and below interior of cap rail. Center bolt lowered only for aethetics of design/it Looks better than centered!

External plates, instead of the internal ones, can be inspected visually and if caulking is necessary; it is easy to accomplish. -CSY interior plate used 6 bolts-the circular external 10"design uses 8 (and countersunk bolts that are easy to bed/seal; note: I do not recommend External Hex Head bolts which catch a lazy sheet and are more likely to suffer from crevice corrosion under their heads as they are near impossible to keep caulked/sealed perfectly.

NOTE: The Single 2" Tang design was scrapped by me.The Advantage of wide double hole tang was too overpowering to dismiss, so all plates were made with 4" tang. 
 (Click on any photo to enlarge it).

Use of flat Socket Head bolts (special order)sit flush with the outer plate and offer a strong grip for tool installing or removing that Slot or Phillip heads do not. CSY, the flat head end of the chain plate bolt was embedded in the rub rail and not accessible. -Going to "external plates", gives you the option of easily changing out bolts if you are concerned as they are not embedded but installing 316 grade bolts in the first place solves future problems. -CSY plates were welded, this design is not.


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S.V. Soggypaws/WT 44, with 10" plates and wide 4" tangs, installed in 2005. Dave chose to remove the teak cap rail, adding instead an aluminum slotted toe rail forward.

Plate project took Dave and Stacey / husband wife team, about a week.

Mounting externally, helps reduce the possibility of oxygen deprivation and therefore should fair better in the elements. Also, they are easy to inspect.

A slightly different twist on the circular design was used by Pete a few years ago, out on the west coast on his boat Imagine. check out this link to his efforts, including his comments on cutting stainless steel using water jet technology and it's very reasonable cost.

www.imaginecruising.com/web/the_boat/repairs_and_reinforcements.htm

As said before, if you were buying a late 70's car of any 'make', you would do a number of things to make sure it is up to specs for a good safe ride. No mater what boat you chose, do the same. Be safe, stay well and keep smiling, it does not add anything significant to the cost of the vessel and really helps to bring back the strength and safety factor.