[Public-List] Forward bulkhead rot

[Rolph and Joan Townshend via Public-List]

For what it is worth - I have been reading the dialog on bulkhead rot and
thought I would enter the discussion with some past experience.
The chain plates make easy access for water to get to the bulkheads over
the many years the  A30's have been active. Repair is not new - it has been
done many times with success.
First of all I don't recommend trying to "harden up" the rot with epoxy or
"get rot" The bulkheads are structural components of the rig and take huge
forces. They must be structurally sound in every way.
When we discovered a bulkhead with rot it was usually very badly rotted -
to the point where there was consideration of replacing the whole bulkhead.
On one occasion that is what we did, and with success. But it was not easy.
Getting the old one out was difficult, but getting the new one fitted into
place was even more difficult. (and the 3/4 marine mahogany plywood is very
expensive). So what we do now is to cut the bulkhead straight down from the
deck to the bottom at the hull about 1 foot in from the outer edge of the
bulkhead. Remove the chain plates and the attachment bolts and pull out the
rotten piece. Using what is left of that piece as a template, cut a piece
of 3/4 marine plywood the same size and put it in place with a snug fit up
under the deck. Take another piece of the 3/4 ply and cut it to overlap the
first piece top to bottom, but well over the* original* bulkhead in the
hanging locker. Where this piece will cover the chain plate in the locker
chisel out 1/4" deep area that will allow the chain plate to seat between
the two pieces. Put the chain plate in place and predrill the 3 holes
through the first ply piece, Put the second piece in place and drill the
chain plate holes from the first piece through the chain plate and on
through the second ply piece. Coat the second piece with epoxy and put in
place, put the chain plate bolts in place and secure the two pieces of 3/4
ply together with at least 10 SS bolts to tie the new ply to the old ply
and attach the two 3/4 pieces to the flange down the inside of the hull
with new, longer SS bolts, all nuts in the locker. To finish this get a
piece of 1/4 or 3/8 mahogany ply (one sided) and epoxy that to the forward
cabin side of the repair, overlapping the old bulkhead by at least 6" with
SS oval head screws and apply varnish. The chain plate is bolted in place
with 5/16 SS shafted bolts (not threaded the whole length of the bolt
shaft). It is good to have a 1" X 1/4' piece of AL or SS in place of
washers on both sides of the repair holding the chain plate in place. As an
additional precaution we went to Bacon or to West Marine and got an 8 "
chrome 3 hole extension plate and extended the chain plate from the bottom
bolt on the locker side down the new bulkhead pieces for two more SS bolts.
Now we have 5 bolts spreading the forces down the new bulkhead. These
repairs have lasted well over many years IF there is no more water getting
down the chain plate into the wood. Seal the chain plate well on deck.
Build 3/8" thick fiberglass caps around each of the 6 chain plates on deck
to seal them in place to keep water from draining into the bulkheads around
the chain plates.
Towney