I have been participating on and monitoring the Cherubini forum since 2007. I don't recall seeing much (if anything) about removing the Cherubini Hunter 36 clamshell (or "Sea Hood") cover that is above the sliding hatch.
I did remove mine last week. I thought to describe ...
Firstly before you consider doing any of the steps below I should recount that after I took off the clamshell, I discovered that on my boat at least I am able to remove the sliding hatch without first removing the clamshell. Screwed on the bottom side of the forward end of the clear/smoked plexiglass sliding hatch is a piece of teak railing. The deck molding has a corresponding upward extrusion which is what stops the sliding hatch from going past the fully closed position. From inside the boat with the hatch closed, if one pushes up hard on the forward side of the sliding hatch, the teak stop rail will just clear the corresponding deck extrusion. This might take some effort. But once the teak rail is over the deck stop, the hatch can slide out and be removed completely for inspection/repair. Once removed one can unscrew the side teak rails to use again if new plexiglass is desired. Or if everything is OK but a leak between the plexiglass and teak side rails is suspected, then remove the rails and apply caulk. Then reinstall the rails.
Anyway now for how I removed the clamshell and what I found underneath:
1) Regarding the FRP molded deck shape underneath the clamshell. It is gelcoat surfaced FRP with no joints. I saw no joints or gaps that can cause leaks or that might be in need of reseal. Any water that may make its way past the caulked joint (that is all away along the perimeter of the clamshell) will just gravitate aft an flow out over the cockpit bulkhead.
2) Nothwithstanding 1) above:
a) The holes for the screws that secure the clamshell to the deck I suppose could allow water leakage onto the top surface of the interior liner. If this is suspected, just remove the screws put in new caulk and put the screw back in.
b) At the hard bends in the deck mold, I did find some visible voids between the gelcoat surface and the underlying FRP layup. This I have read the does happen on production boats because after the wax then gelcoat is sprayed into the mold, at the locations with tight bends and angles, the next layer of resin and fiberglass cloth sometimes can't flow fully around the angle. Many years later when the gelcoat ages/cracks/is damaged, these gaps/voids become exposed. Notwithstanding this, between the clamshell caulk and sealant and that water could at the most collect in the small void, a leak from this layup "flaw" is unlikely.
3) I don't think that my clamshell had ever been removed by PO's. The original caulk/sealant was still in great shape. Adhering to both the clamshell and deckmolding surfaces and still very flexible.
4) To remove the clamshell:
a) Unscrew and remove the port and starboard end-stop pieces onto which the outboard blocks are attached. (Good luck -- mine were frozen solid due to galvanic corrossion between Al and SS.)
b) Remove the three bolts on each port and starboard sides of the traveler rail that screw into the deck molding. Note it is not necessary to remove any of the bolts that connect the rail to the clamshell.
c) With a razor knife, sever the caulk joint between the clamshell and the deck.
d) With a pry-bar, and with a piece of wood underneath it to protect the deck and to add leverage, carefully separate the clamshell from the deck.
5) Re-installation is essentially the reverse of the above. I found that the original caulking was still pliable and still firmly attached to the deck molding into which the clamshell is recessed. So I just layed a layer of new sealant over. Then put the clamshell back into positions. Resecured with the screws. Then a new bead of caulk/sealant is necessary for cosmetic appearance and to minimize any puddling of water along the surface of the seam.
6) Of course adequately bed caulk (or I suppose Maine Sail's butyl tape) around the bolts that secure the traveler rail into the deck and also for the end stop pieces.
A few pictures attached.
I did remove mine last week. I thought to describe ...
Firstly before you consider doing any of the steps below I should recount that after I took off the clamshell, I discovered that on my boat at least I am able to remove the sliding hatch without first removing the clamshell. Screwed on the bottom side of the forward end of the clear/smoked plexiglass sliding hatch is a piece of teak railing. The deck molding has a corresponding upward extrusion which is what stops the sliding hatch from going past the fully closed position. From inside the boat with the hatch closed, if one pushes up hard on the forward side of the sliding hatch, the teak stop rail will just clear the corresponding deck extrusion. This might take some effort. But once the teak rail is over the deck stop, the hatch can slide out and be removed completely for inspection/repair. Once removed one can unscrew the side teak rails to use again if new plexiglass is desired. Or if everything is OK but a leak between the plexiglass and teak side rails is suspected, then remove the rails and apply caulk. Then reinstall the rails.
Anyway now for how I removed the clamshell and what I found underneath:
1) Regarding the FRP molded deck shape underneath the clamshell. It is gelcoat surfaced FRP with no joints. I saw no joints or gaps that can cause leaks or that might be in need of reseal. Any water that may make its way past the caulked joint (that is all away along the perimeter of the clamshell) will just gravitate aft an flow out over the cockpit bulkhead.
2) Nothwithstanding 1) above:
a) The holes for the screws that secure the clamshell to the deck I suppose could allow water leakage onto the top surface of the interior liner. If this is suspected, just remove the screws put in new caulk and put the screw back in.
b) At the hard bends in the deck mold, I did find some visible voids between the gelcoat surface and the underlying FRP layup. This I have read the does happen on production boats because after the wax then gelcoat is sprayed into the mold, at the locations with tight bends and angles, the next layer of resin and fiberglass cloth sometimes can't flow fully around the angle. Many years later when the gelcoat ages/cracks/is damaged, these gaps/voids become exposed. Notwithstanding this, between the clamshell caulk and sealant and that water could at the most collect in the small void, a leak from this layup "flaw" is unlikely.
3) I don't think that my clamshell had ever been removed by PO's. The original caulk/sealant was still in great shape. Adhering to both the clamshell and deckmolding surfaces and still very flexible.
4) To remove the clamshell:
a) Unscrew and remove the port and starboard end-stop pieces onto which the outboard blocks are attached. (Good luck -- mine were frozen solid due to galvanic corrossion between Al and SS.)
b) Remove the three bolts on each port and starboard sides of the traveler rail that screw into the deck molding. Note it is not necessary to remove any of the bolts that connect the rail to the clamshell.
c) With a razor knife, sever the caulk joint between the clamshell and the deck.
d) With a pry-bar, and with a piece of wood underneath it to protect the deck and to add leverage, carefully separate the clamshell from the deck.
5) Re-installation is essentially the reverse of the above. I found that the original caulking was still pliable and still firmly attached to the deck molding into which the clamshell is recessed. So I just layed a layer of new sealant over. Then put the clamshell back into positions. Resecured with the screws. Then a new bead of caulk/sealant is necessary for cosmetic appearance and to minimize any puddling of water along the surface of the seam.
6) Of course adequately bed caulk (or I suppose Maine Sail's butyl tape) around the bolts that secure the traveler rail into the deck and also for the end stop pieces.
A few pictures attached.
