Does anyone know if the mast base mates directly to the top of the compression post, or are they separated by the the cabintop shell? I would assume that the shell is cutout to allow them to meet and maybe even bolt up. In any case, I have bee chasing leaks and just discovered that there is a marked depression in the raised area around the mast base. If you look below, it also shows up, though not as much deflection as above. The sole shows an even slighter depression. This boat has had a section of compression post cut out and replaced,from the sole plate down to its bearing on the keel. I'm wondering if this deflection is just a function of time and mast loads over the years or it could be evidence of further deterioration of the balance of the compression post. And if there is a cut out in the cabintop at the base of the mast, I can assume that it probably is leaking. The boat in question is a 1978 H30.
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Brett
No cutout
The mast base is fastened to the raised area on deck with some small bolts, but there is no cutout to the compression post. I had the same depression in the mast step area, caused by decaying of the core. I had to have the mast step area rebuilt, by removing the top skin installing new core and sealing up again with fiberglass and gelcoat. Your leak could be from the bolts that hold the mast step down, or from the mast wiring that penetrates the deck in that area.
The mast base is fastened to the raised area on deck with some small bolts, but there is no cutout to the compression post. I had the same depression in the mast step area, caused by decaying of the core. I had to have the mast step area rebuilt, by removing the top skin installing new core and sealing up again with fiberglass and gelcoat. Your leak could be from the bolts that hold the mast step down, or from the mast wiring that penetrates the deck in that area.
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Kevin Whalen
The cut out is a hole
The only cut out on my 40 is a round hole, through the deck, in the center of the base for wiring to pass through into the top of the compression post. The hole is about 1.5 to 2.5 inches in size.
The only cut out on my 40 is a round hole, through the deck, in the center of the base for wiring to pass through into the top of the compression post. The hole is about 1.5 to 2.5 inches in size.
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David Foster
Archives, Cabin top structure
There are lots of excellent discussions in the archives under mast step, or compression post, or similar words. I believe your structure (top down) is the same as our '77 h27 where we fixed this problem this spring: 1. Aluminum step piece 2. Fiberglass over pad 3. Plywood pad (will rot if water penetrates) 4. First fiberglass layer of cabin roof 5. Balsa core of the cabin roof (will rot if water penetrates) (some people have reported plywood here, too.) 6. Second fiberglass layer of cabin roof 7. Cabin roof liner You get pictures and measurements to help in rebuilding the structure. Remove the step, and plastic pipe holding the electric cables (we removed the connectors, and pulled them down into the cabin to wait for pulling them through the rebuit step), then remove the pad cover and pad. Then cut the first layer of the roof away to reveal the balsa core. (We cut out the shape of the long transverse part of the pad.) Remove the balsa until you get to clean, good wood. We ended up undercutting our hole by two to four inches. Then, you rebuild the step. We made a flat bed of epoxy, and when it hardened, put an aluminum plate in the hole and filled around it with epoxy to flow back under the first layer. Aluminum gives stiffness to spread the load, is cheaper than epoxy, and takes no time to set. (you really need to let each layer of epoxy cure before the next - this will form the time-line of the project!). Then grind the first layer of the deck, fair in a new fiberglass layer, and rebuild the pad. Finally, you drill new holes for the cable tube, install it (we used 5200) and drill holes for the bolts holding the aluminum step. We used 5200 again to surround these bolts, and mount the step. Our new mast step, looks like new, there is never any deformation of the cabin roof when I tune the rigging properly, and all of my shrouds were shortened so they have more room to adjust them! Good luck with this repair. It's all straightforward work, and you can build a solution that will last even longer the the 25 years we got out of our first one. David Lady Lillie
There are lots of excellent discussions in the archives under mast step, or compression post, or similar words. I believe your structure (top down) is the same as our '77 h27 where we fixed this problem this spring: 1. Aluminum step piece 2. Fiberglass over pad 3. Plywood pad (will rot if water penetrates) 4. First fiberglass layer of cabin roof 5. Balsa core of the cabin roof (will rot if water penetrates) (some people have reported plywood here, too.) 6. Second fiberglass layer of cabin roof 7. Cabin roof liner You get pictures and measurements to help in rebuilding the structure. Remove the step, and plastic pipe holding the electric cables (we removed the connectors, and pulled them down into the cabin to wait for pulling them through the rebuit step), then remove the pad cover and pad. Then cut the first layer of the roof away to reveal the balsa core. (We cut out the shape of the long transverse part of the pad.) Remove the balsa until you get to clean, good wood. We ended up undercutting our hole by two to four inches. Then, you rebuild the step. We made a flat bed of epoxy, and when it hardened, put an aluminum plate in the hole and filled around it with epoxy to flow back under the first layer. Aluminum gives stiffness to spread the load, is cheaper than epoxy, and takes no time to set. (you really need to let each layer of epoxy cure before the next - this will form the time-line of the project!). Then grind the first layer of the deck, fair in a new fiberglass layer, and rebuild the pad. Finally, you drill new holes for the cable tube, install it (we used 5200) and drill holes for the bolts holding the aluminum step. We used 5200 again to surround these bolts, and mount the step. Our new mast step, looks like new, there is never any deformation of the cabin roof when I tune the rigging properly, and all of my shrouds were shortened so they have more room to adjust them! Good luck with this repair. It's all straightforward work, and you can build a solution that will last even longer the the 25 years we got out of our first one. David Lady Lillie
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Bob
Compression post interface
The interface on my 78 H33 is probaly identical to yours. Basically there are two layers of wood between your mast step and compressions post. The raised boss is fiberglass encapsulated plywood under which is some fiberglass and then the balsa core. If you see a depression around your mast base (I speak from experience here) then you are compressing the wood sandwich and the mast is driving into the deck structure. To repair my sinking mast I removed the step area and an area around it until I got clean dry balsa. I removed all of the wood between the step and the compression post. I rebuild the compression area with fiberglass cloth and epoxy resin. Outside of the step I replaced the damaged balsa and wetted the new balsa with penetrating epoxy. The whole process souns worst than It was. It took about 3 days to complete the repair including new two part polyurethane paint and non-skid. You can't tell that the area has been repaired. The cause of the damage was water infiltration inot he core, in my case it was coming in through the electrical connector next to the mast. All of my electrical connections are now made inside of the mast and are at least 6 inches away from the closest wood.
The interface on my 78 H33 is probaly identical to yours. Basically there are two layers of wood between your mast step and compressions post. The raised boss is fiberglass encapsulated plywood under which is some fiberglass and then the balsa core. If you see a depression around your mast base (I speak from experience here) then you are compressing the wood sandwich and the mast is driving into the deck structure. To repair my sinking mast I removed the step area and an area around it until I got clean dry balsa. I removed all of the wood between the step and the compression post. I rebuild the compression area with fiberglass cloth and epoxy resin. Outside of the step I replaced the damaged balsa and wetted the new balsa with penetrating epoxy. The whole process souns worst than It was. It took about 3 days to complete the repair including new two part polyurethane paint and non-skid. You can't tell that the area has been repaired. The cause of the damage was water infiltration inot he core, in my case it was coming in through the electrical connector next to the mast. All of my electrical connections are now made inside of the mast and are at least 6 inches away from the closest wood.
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David Popken
Thanks David, but.....
no luck with an archive search. I think I get the picture. Essentially there are three layers of fiberglass and two layers of either plywood and balsa or just plywood separating the top of the compression post from the mast base. And what I am seeing is the compression of the wood core due to water penetration and wood rot. My to do list keeps growing.
no luck with an archive search. I think I get the picture. Essentially there are three layers of fiberglass and two layers of either plywood and balsa or just plywood separating the top of the compression post from the mast base. And what I am seeing is the compression of the wood core due to water penetration and wood rot. My to do list keeps growing.
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