Replacing chainplates

[Eric and Jean]

We are in the process of buying a CSY 37 in need of new chainplates. We are thinking about replacing them with exterior plates. We would appreciate any input.

[GrowleyMonster]

Make sure you reinforce the area with 3 or 4 layers of mat, at least. And you want nice big chainplates and backing plates, and lots of bolts. It is a bad thing when bolt holes in a transverse bulkhead elongate, but a really really bad thing when holes through the hull elongate. I have done this but please understand that there could be negative consequences.

Oh, and make sure you have a rubrail to prevent bolt heads from scratching up any other boat you might rub up against. You could really tick off some folks! Remember, stuff happens.

[roverhi]

The hull thickness should be more than adequate to support the chainplates.. If you feel the need to add additional reinforcing, make up a back up plate out of fiberglass sheets available from McMaster Carr and epoxy that in place as you install the chainplates. When I replaced mine, cut down the old chainplates and used them as backing for the new chain plates.

[hugosalt]

Don't think much of a move outboard but you may
seek input from CSY forum/owners members who may
have changed to exterior plates...or may have reasons for opting against changing. Or look up designer Peter Schmitt, if still with us, many of the designers are accessible to talk about their designs.

[barnakiel]

You can't just just take inboard plates, reinforce the topsides and convert to outboard plates. Talk to the designer.

If you move the plates to another location, make sure the new location is at least as strong as the old one. It may take reinforcements as per above posts, but it make take some more structure reinforcement.

Personally, I would think twice - I have seen external chainplates 'removed' from a boat when she came into sudden contact with a rough concrete dock. They definitely have huge advantages, just think twice before you jump.

b.

[Jim Cate]

Just curious: why do you want to make this modification? ONe would think that CSY put them inboard (or wherever they are originally) for good reasons, and they seem to have lasted for a good many years so far.

I'm not criticizing your idea, just wondering about reasons!

Cheers,

Jim

[MarkSF]

Originally Posted by Eric and Jean

We are in the process of buying a CSY 37 in need of new chainplates. We are thinking about replacing them with exterior plates. We would appreciate any input.

I'm afraid this is one case where I don't understand the logic. The chainplates are what, 30 to 40 years old, but you want to re-locate them, presumably due to a fear of unseen crevice corrosion. Would you say they have had an unreasonably short life, then?

On my Bristol the plates are fixed to massive bulkheads and you could not reasonably reinforce the hull to an equivalent strength.

Just re-install new ones in place of the old ones, where the boat's designer meant them to be, and "only" get another 30 to 40 years of life.

[Eric and Jean]

We would like to thank everyone for their input. Unfortunately, we were unable to give the owner an offer in writing as the broker left us hanging...not sure what happened but looks like we are looking for a boat again.