Aluminum chainplates

[mrgnstrn]

Hello all.

I recently had my mast unstepped for some overdue rigging work.
As a result the chainplates became clearly visible for the first time since owning the boat (only 3 years).

The chainplates are all aluminum, 4" wide plate, 1/2" thick and run from the deck through the cabin, and are secured by a bunch of bolts into massive stringers glassed into the hull.

Since there was this aluminum-stainless connection, the expected thing happened, and the aluminum has flaked off in the areas where the turnbuckle toggles where coving.

So, something needs to be fixed.

Going to all-stainless is the obvious solution, but really expensive. These buggers are 40" long, 4" wide, and 1/2" thick. We could go to 1/4" thick plate, but still has to be 4" wide to have enough room for 3-shrouds to attach to it.


I am currently exploring the keep-it-the-same approach because it has taken 21 years to get to the point where something must be done, all on the salty Chesapeake. Plus, the 37" of material that is inside the boat, cabin, bolted to the stringer, is perfect looking. No defects at all. The problem is isolated to the 3" that stick up on deck.
So, anyone have a clue what material they might be made of?

Pictures here: http://members.cox.net/btsrefit/chainplate.html
Other pertinent details:
1987 C&C 35

Keith