Sailboats with visible or exterior chainplates

[BobLoucks]

Originally Posted by waterman46

Morgans mostly (perhaps all?) have external chainplates. I like them for the above reasons but primarily because there are six less places on deck for leaks. Thru-deck chainplates can be difficult to seal reliably due to the repeated flexing of the deck and small movement of the chainplate while tacking. You have only a small area there to make a good seal while if they are mounted outside hull it is easy to get a very good permanent seal. I have seen a few boats where the internal plywood bulkheads have been severely damaged by leaks from the shroud chainplates.

With external plates you also have three fewer obstructions on the deck as you go forward.

Most boats in the last 40 years were built with more beam for stability and roominess - than moves the shrouds out as well, if they are external. Anything bigger than a "working" jib must be sheeted outside the shrouds and the angle is wider than optimum when chainplates are external. It only affects sail trim when sailing close-hauled. For many cruisers, the trade-off is worth it.

I have a Morgan 37 OI with external chain plates. Love them especially for moving around the deck in rough water. Sailed down the east coast from NYC to Tampa on a vessel with inboard shrouds, they are a PITA and yes they leak. External plates are not for racing but great for cruising.

[billgewater]

Originally Posted by Cheechako

There have been quite a few traditional types. Mystic 30, Westsail I think? As mentioned, sheeting angles suffer. Sometimes I wonder if it is better for corrosion? One side of the chainplate is still "enclosed," and if water were seeping in there it could still corrode fast. And the chainplate is exposed to salt water a lot compared with one thru deck. Still... I like the outside mounting.

Another consideration is that if you use SS bolts through a timber hull to attach the external chain plates, then if water ever does ingress and creates rot around the SS bolts in the wood, the environment can become very conducive to SS rusting away quickly. I experienced this many years ago when wiping down the inside of a small timber yacht after a fairly rough trip to Rottnest Island from the Swan River in Western Australia. I knocked off some internal nuts on the backing plates and showed them to the owner who was obviously upset. Back at the marina, he removed all the SS bolts to find that many of them had turned into a black soft mush in the wet rotting wood. I understand he cleaned out the holes then oversized them, filled them with epoxy and redrilled them so that the new bots were not exposed to the timber environment. This issue may be very dependent on the type of timber, but I was told that the environment of salt water and an "anaerobic" environment were the villains.
This may not have been a problem with older bronze assemblies, but a check may save some serious grief - like a fallen mast.

[MarkusK]

SV Prism is a Hans Christian 33 which has internal chainplates. They converted to external. Starts at 1:30.

https://www.youtube.com/watch?v=GIt2ceIr1zY

[Hoodsail]

Another option is to have the chain plates through the deck and then bolted to bulkhead reinforced with steel mounting plates like my 1978 Bristol is. Bought her 2.5 yrs ago at which time i removed the bolts that held the plates to the bulkhead, the yard removed and examined each plate.....they looked brand new, no evidence of corrosion. I remounted them ....good for another 35 ish years...

[ronbo1]

Gozzard is one of the few builders still in business. They’ve started using carbon fibre for key components - like exterior chain plates.

Ronbo

[MartinAdelaide]

My 1979 Austral has chainplates just inside the toerail and fixing around the timber beam shelf. Water has gone down and the timber is now totally gone. I'll be putting external on. Later models have the plates at the cabin/deck join.

[CGirvan]

sorry if this is a bit of thread drift. I've often wondered when seeing external chainplates, if these were extended down to the waterline whether this would help in a lightning strike. Interested in your thoughts.

[ZULU40]

Originally Posted by CGirvan

sorry if this is a bit of thread drift. I've often wondered when seeing external chainplates, if these were extended down to the waterline whether this would help in a lightning strike. Interested in your thoughts.

for that you can use a bonding system,
linking all the significant hardware, thru hulls and the rig with heavy gauge wire