CAN ANYONE TELL ME WHAT THICKNESS AND HOW MANY PLY THE BULKHEADS ARE MADE FROM ON THE ODAY 25 (1978)
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Rick, don't want to leave you waiting. I know the bulkhead is 1/2 plywood.
I know that there are many good posts in the archives. If I had first hand info, I would have given to you. Look in the archives and be patient... Someone that has taken this on will reply. r.w.landau
I know that there are many good posts in the archives. If I had first hand info, I would have given to you. Look in the archives and be patient... Someone that has taken this on will reply. r.w.landau
Rick, The old bulkhead was 1/2" ... That is what fits.
Replace what you have, the 1/2", but protect it. The most stressed part of a boat is the bulkhead that the chainplate is bolted to. This is a dynamic. Dynamic meaning that it moves. The bulkhead is a solid stucture that can take a vertical load with no problem. That is great if the bulkhead doesn't move. I will in as few words ask possible explain this. The bulkhead is a solid piece of plywood that is is pulled from an end. It is very strong. Then you have the hull and the deck as non stuctural because they are horizontal to the pull of the shroud. The strength of the shroud is transmitted to the bulkhead connection to the deck. Any way, You need to make sure the bulkhead is tight to the deck so that there is noooooooooooooooo, movement. If the bulkhead is not fit correctly, the chainplate will flex up and down as the bulkhead is pulled up and then released so that it settles down. Sealants only flex to a portion of an inch. If the chainplate moves more than the flexibility of the caulking/sealant the leak will start...again and dump water on to the new bulkhead. Caulking doesn't flex that much. Once you get tension on the chain plates, check that the deck plate is not leaking. Any amount of flex will break this bond and the leak will damage just like the old factory leak. The chainplate area (second to stanchions) will leak first. The dynamic stress is the problem. Use a dynamic sealant here. Ok, Bring in the engineers!
r.w.landau
Replace what you have, the 1/2", but protect it. The most stressed part of a boat is the bulkhead that the chainplate is bolted to. This is a dynamic. Dynamic meaning that it moves. The bulkhead is a solid stucture that can take a vertical load with no problem. That is great if the bulkhead doesn't move. I will in as few words ask possible explain this. The bulkhead is a solid piece of plywood that is is pulled from an end. It is very strong. Then you have the hull and the deck as non stuctural because they are horizontal to the pull of the shroud. The strength of the shroud is transmitted to the bulkhead connection to the deck. Any way, You need to make sure the bulkhead is tight to the deck so that there is noooooooooooooooo, movement. If the bulkhead is not fit correctly, the chainplate will flex up and down as the bulkhead is pulled up and then released so that it settles down. Sealants only flex to a portion of an inch. If the chainplate moves more than the flexibility of the caulking/sealant the leak will start...again and dump water on to the new bulkhead. Caulking doesn't flex that much. Once you get tension on the chain plates, check that the deck plate is not leaking. Any amount of flex will break this bond and the leak will damage just like the old factory leak. The chainplate area (second to stanchions) will leak first. The dynamic stress is the problem. Use a dynamic sealant here. Ok, Bring in the engineers!
r.w.landau
Bulkhead replacements
Rick: There is an O'Day 25 having this procedure done at the marina where I keep my O'Day 26, which can be subject to the same issue. I would suggest that the old bulkhead be removed in such a way that it can be used as a template for a new bulkhead. I doubt that number of plies is as important as the overall quality of plywood. That is a plywood wood of high quality either marine or exterior for structural uses. It can be made stronger thru use of epoxy and or glass. To help prevent this issue from reoccurring, all ends the plywood should be sealed with epoxy. After holes are drilled for chain plates the holes should be sealed with epoxy. I have forwarded your question to a O’Day 25 owner who has made this repair. Also, recently we had post from a 26 owner who did extensive rebuild, see link. It has to be accessed by the archives. Ed K 26
Rick: There is an O'Day 25 having this procedure done at the marina where I keep my O'Day 26, which can be subject to the same issue. I would suggest that the old bulkhead be removed in such a way that it can be used as a template for a new bulkhead. I doubt that number of plies is as important as the overall quality of plywood. That is a plywood wood of high quality either marine or exterior for structural uses. It can be made stronger thru use of epoxy and or glass. To help prevent this issue from reoccurring, all ends the plywood should be sealed with epoxy. After holes are drilled for chain plates the holes should be sealed with epoxy. I have forwarded your question to a O’Day 25 owner who has made this repair. Also, recently we had post from a 26 owner who did extensive rebuild, see link. It has to be accessed by the archives. Ed K 26
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