Swithing to chain plates??

[Tia Maria]

Any one everthought about switching to chain plates? My little boaxes are pretty wasted so I have to do something and re inforcing the area with epoxy glass on the inside and having a set of big luscious chain plates would look really cool I think...and I need a small (a single seat) bow pulpit/bowroller out of cheap wood stained and varnished to look expensive also ...I am a hairy tick??
Cheers, Terry

 

[Whit]

If you don’t remove the original iron chain plates they will continue to deteriorate and bleed through the gel coat. After replacing mine, I recommend removing from the outside and replacing with stainless. Not a difficult job.
Good luck

 

[jeldert]

Whit - I am an owner of a Zephyr (939-F) and am very interested in knowing whether the Zephyrs and Mistrals chainplates should be replaced from the inside or the outside. I have heard that the Mistral "Meltemi" had her chainplates fixed from the outside by Burr Bros. in Marion, MA - from the outside, but don't yet have confirmation of that. I would really like some definitive determination of which is the best approach, since MOTH's chainplates are weeping significantly through the hull, and I'd like to attend to them quite soon. (sort of a toss-up between that project and rebuilding the rudder)

Thanks,
John Eldert
Waquoit Bay, MA (Nantucket Sound)

 

[TomY]

Hi John, bring me up to speed. Are your chainplates, hat frame and backing plates the same as the Challengers? If so, we do have info on replacing those we can help you with.

 

[Whit]

Tia Maria- One reason for replacing the chain plates from the outside is that the interior cabinetry does not have to be removed, some of which may have been installed before the deck was attached. Keep in mind that by working from the outside the hull will probably need a complete paint job of some sort. Another advantage to working from the outside is that the new patch can be spread over a much larger area as it is not limited to the area between bulkheads. The cabinetry takes a bit of craftsmanship to keep intact so I would think there would be a lot of labor savings to working from outside which might offset the paint job. Also, you don’t have to be a contortionist to work from the outside, those lockers get tight. Good Luck & let us know how you make out.
Whit

 

[CaravelaofExe]

Sounds rather drastic to breach the hull lay-up from outside when - presuming all 4 types being to the same drawings - the chainplate isn't attached directly to the hull at all. On Halmatic Caravelles (not sure what Hodgdon did) and Challengers, the chainplate is attached by stainless steel machine screws through the inner (ie. chainplate can easily be seen once hull ceiling removed) face of a "top-hat" frame, with the apparently problematical part being the mild steel backing plate that is encased inside the top-hat frame.

As Tom says, much has been written and illustrated on previous threads about proven methods of dealing with this from inside; it's worth scrolling down to find out. Of course, access can be a big problem...

Although the photos of corroded mild steel backing plates look bad, to the best of my knowledge there is no record, over coming up for 50 years, of a history of chainplate failures. Surely this is because the the backing plate takes a secondary mechanical role to the top-hat frame itself.

Whit mentions iron chainplates. Mine are stainless steel. Interested to know about others...

 

[TomY]

As mentioned somewhere, I've removed one by cutting the side of the fiberglass hat frame. As Iain mentions, the rusted mild steel backing plates simply act as a fastener (it's threaded) to secure the SS chainplate to the hat frame. The one I removed, while quite rusty. was in no danger of allowing the chainplate to leave the hat frame.

I may remove another one this year as I'm anxious to try it by simply cutting the bottom of the hat frame. If this works, it will not reduce the strength of the fiberglass hat frame, will be faster than cutting into the side as I did, and will leave a good area for the hat frame to drain. They do collect water from the deck due to the channel created when Hallmatic glassed the hull to deck.

(theres' more info on this on the site)

 

[jeldert]

Thanks, Tom and Ian - it does sound like a similar construction, and to be consistent across all models does make a lot of sense. That's why I asked, since I couldn't quite believe that Burr Bros. in Marion just chopped their way though the topsides for the Mistral repair. Their does seeem to be some slight hollowing of the outside layup which can be seen in oblique lighting, that does suggest the concept of a molded pocket - but that could be the pull of how the pocket was glassed to the inside of the hull?

I like Tom's thought about providing drainage, as I had drilled a 1/4" hole in one of the pockets a couple of years ago, and that is the only one that is not bleeding rust through the topsides. Seems like draining and ventilation might be a good initial test, since structural failure doesn't seem to be a risk, as you indicate.

Parenthetically, it sure is great to have this site!

(Next project is to investigate whether I can replace the after section of the rudder without disturbing the portion attached to the pintals and rudder shaft - I did see the rudder repair topic elsewhere, so that is a comfort to be able to consult. )