If I had extra time, I've thought about adding a second fiberglass flange to the opposite sides of the bulkhead along the hull sides and through bolting the bulkheads through both flanges with larger bolts.
My concern with this it that it might cause the bulkhead to rot more quickly where it is buried in the flanges, but it would probably help keep the bulk head from moving as much while still allowing some flexing.I don't know if adding a fiberglass flange to the cabin roof above the bulkhead/mast beam under the mast would work or not. The deck is cored there and I think the inside skin is thin.
It may also be a good thing to have some movement there as well, probably someone that knows a lot more about this me will let you know. I will probably make the time to add a stainless compression beam under the mast with flanges top and bottom (to create a void for wiring and allow air circulation as well as stiffening the beam).
The wood beam that is in there now has some hard putty (probably thickened fiberglass resin) above the beam to fill between the beam and cabin roof. The putty is cracked along either the cabin roof or the beam (I forget which)
so there may have been movement in that area at one time. I'm not so sure if bolting the mast base to the ss flange is a good idea. The fiberglass flanges are usually put in with a 45 degree foam chamfer to allow for some flexing of the hull.
-Tim
________________________________
From: John jdnalaska@...
To:
AlbinVega@yahoogroups.com
Sent: Tuesday, June 5, 2012 2:56 PM
Subject: [AlbinVega] Re: Washington Post article
I'm very interested in this as I'm rebuilding my boat. It is now bare hull and deck only. I'm assumming Matt's cabin lift is related to chain plate stress. Of course there is the famous mast compression issue. Would it work to address both (after beefing up the bulkhead and beam) to put a flange on the inside of the cabin roof and thru bolt the mast support beam to this? Mast support solutions depend on compression, but a flange would make the cross section of the boat beneath the mast (including the bulkhead) very rigid and address forces in all directions. Maybe this is not totally a plus.
John