9/10/2021
A couple of observations from the future. Please excuse repetitions!
In short, my laminated beam across the cabin has no other support
except for the overbuilt gussets at the chainplates at the center shroud.
I laid in a substantial floor (Cross piece timber) at the step up into the
front cabin. Which in Litlgull no longer exists because the bulkhead
is removed (forward as a 'crash bulkhead').
I recorded the height from the floor timber to the bottom of the
laminated beam. But then I read that the tanins in white oak may react
with the resorcinol.. So I thru-bolted the whole thing to the cabin top
with bronze carriage bolts. Measured the height with mast and rig and
found barely 1/8" less. Seems OK. The unitized laminate, bolted and
glued up-graded deck (balsa replaced with solid frp), immovably supports
the mast with all its active downward pressure. We'll see! And, just in
case, a compression post, like the Commander's, could easily slip in
between the cross-floor and the cross-beam.
Someone here pointed out a pole in the middle of the accommodation
isn't a bad thing -- you use it to swing around or just as a steady-hold in
an often very active little ship..
That's A338. Our discussion here finds that the problem with the strong
back is not rot but the settling of the dry fitted pieces under rig pressure
over time.
For those skippers restoring their Ariels, I would suggest removing the
main bulkhead. Put in a substantial floor across the bottom at and as the
step up. Block the crossbeam into its final position if it's in good shape.*
Might GLUE it to the cabin top with rubber cement (4200). Then reframe
the passage way with substantial posts to support the venerable beam.
Thus we have the hull and cross-floor supporting the strongback. Finish
the bulkhead in an interesting plywood of your choice. Doorway can be
kept open with a privacy curtain for air circulation.
*May have to return the mast-DECK to its original curve with a jack -- and
repair any balsa-rot. If I remember the balsa is 3/8". Remove the deck
laminate carefully. Replace rot with glass mat and glue the deck back on.
Hope this still holds true: You cannot find a better marine plywood to
sheathe the bulkhead than BS1088 Meranti. It is made with phillipine-like
mahoganies and bonded under high pressure with phenolic glue. The
veneers are knotless thruout, panel is flawless and deadflat. Could get
by with the 6mm but 9mm will allow left overs for shelves and such. Easy
to varnish or paint.
This will provide all necessary support for the beam and rig overhead
forever. IMCO