Chain plate separating from deck
- Thread starter FDL S2
- Start date
FDL; The load on the chainplate is carried by the bulkhead. The chainplate is attached by thru bolting the bulkhead to a backing plate. It is hard to imagine the deck lifting if the bulkhead bolt holes and bulkhead are solid. The decks c-plate cover, seal, and rot are also a problem but will not solve the c-plate movement. Look closer at the bulkhead, (both sides) boltholes, wood condition, or movement in the tabbing? Resin--polyester will work well. Its adhesive property is more than enough to do the job, it will cut you job time and costs at least 1/2 of expoy. My 2nd choice is vinylester. Your prep. of the area is more important than resin type. I usually purchase any of the 4 resin types thru Express Composites.
No, here is why: the bulkhead is not attached to the deck at all-it sits about 3/8" below the glassed in core of the deck. The cover being welded to the plate solidly attaches the deck to the bulkhead giving it structure. If I grind off the cover, the bulkhead (which the chainplate is attached to) and the deck can move independent of each other which may cause the chainplate to enlarge the hole it passes through on the deck. This will allow water in, crack the gel coat and fiberglass on the deck and put stress on the repaired core. I will just have to make sure I do a good job of sealing it tight.
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 23,786
That is not the engineering I understand.
The bulkhead is attached to the hull, thereby pulling the mast down against the hull.
The mast base is against the hull, either the mast is stepped to the hull or in the case of the deck stepped mast there is a compression post that transmits the power in the mast to the hull.
The deck is attached to the sides of the hull.
The chainplate needs to do through the deck. Chainplate movement would be pulling up the hull against the mast and there is some movement at 90 degrees to the length. This movement though small is permitted in the way the plate goes through the deck.
To stop water intrusion a flexible caulking is used to seal the space of the chainplate at the deck. Options are Butyl (my recommendation Bed-It from MaineSail) or 3 M 4000 (Silane Modified Polymer sealants provide strong, flexible durable elastomeric bonds that seal against the elements.) or synthetic rubber sealants called polysulfides (like Life Caulk).
The chainplate cover is used to cover the caulked space of the chainplate.
The bulkhead is attached to the hull, thereby pulling the mast down against the hull.
The mast base is against the hull, either the mast is stepped to the hull or in the case of the deck stepped mast there is a compression post that transmits the power in the mast to the hull.
The deck is attached to the sides of the hull.
The chainplate needs to do through the deck. Chainplate movement would be pulling up the hull against the mast and there is some movement at 90 degrees to the length. This movement though small is permitted in the way the plate goes through the deck.
To stop water intrusion a flexible caulking is used to seal the space of the chainplate at the deck. Options are Butyl (my recommendation Bed-It from MaineSail) or 3 M 4000 (Silane Modified Polymer sealants provide strong, flexible durable elastomeric bonds that seal against the elements.) or synthetic rubber sealants called polysulfides (like Life Caulk).
The chainplate cover is used to cover the caulked space of the chainplate.
I do understand why you are saying, but I think this is a different situation.
The bulkhead I am working on is a small one that is not tabbed to the deck. 1st pic I pulled off the web of the same boat with out the carpet. This is from the v-berth, you can see the chainplate on the bulkhead and that the bulkhead isn't attached to the deck.
2nd pic is my boat and you can see the compression post in the middle to the right of the fold down table. On the far left you can see the aluminum backing plate for the port chainplate. Above the table are bolts that attach the the bulkhead to the deck only at the top of the bulkhead.
3rd pic is a screwdriver stuck between the bulkhead and the deck next to that port chainplate-its not tabbed to the deck.
I reached out on LinkedIn to an old manager from when I worked for a boat builder (not sailboats) for his opinion. He remembered me from almost 20yrs ago and said to send him pics.
I didn't get to do any work on the boat today because I aggravated a repaired Achilles running this morning and I have orders from my physical therapist to keep it elevated and iced and not to move around too much-especially getting on and off the boat (she knows me too well).
The bulkhead I am working on is a small one that is not tabbed to the deck. 1st pic I pulled off the web of the same boat with out the carpet. This is from the v-berth, you can see the chainplate on the bulkhead and that the bulkhead isn't attached to the deck.
2nd pic is my boat and you can see the compression post in the middle to the right of the fold down table. On the far left you can see the aluminum backing plate for the port chainplate. Above the table are bolts that attach the the bulkhead to the deck only at the top of the bulkhead.
3rd pic is a screwdriver stuck between the bulkhead and the deck next to that port chainplate-its not tabbed to the deck.
I reached out on LinkedIn to an old manager from when I worked for a boat builder (not sailboats) for his opinion. He remembered me from almost 20yrs ago and said to send him pics.
I didn't get to do any work on the boat today because I aggravated a repaired Achilles running this morning and I have orders from my physical therapist to keep it elevated and iced and not to move around too much-especially getting on and off the boat (she knows me too well).
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So what you’re gonna do is connect the bulkhead to the deck by two meazly small bolts and with no backing plates..I would also suggest posing this question in the S2 forum and see if others have this configuration. Also talk to a rigger.
It is not unusual for bulkheads to not be tabbed to the deck. Typically when boats are built the deck and all its hardware are assembled while the hull and all the furniture, engine, wiring, bulkheads etc are assembled in the hull. The deck is then lowered on to the hull and secured around the edges. Some boats with molded head liners will have grooves into which the bulkheads fit.
On this boat the starboard chainplate attaches to a knee. The sole purpose of this knee is to transmit the rigging loads to the hull. Bulkheads serve to keep the sides of the hull separated, more than they do to support the deck.
On this boat the starboard chainplate attaches to a knee. The sole purpose of this knee is to transmit the rigging loads to the hull. Bulkheads serve to keep the sides of the hull separated, more than they do to support the deck.