DaveH6
Cabin sole flotation.
I drove myself crazy studying the issue of what type of foam to use. Some say use two part pourable foam. Others say don't pour it if you don't have an ideal temperature and humidity environment during the pour. Others say poured foam can trap moisture.
Some say use empty and capped plastic bottles. Will this sound like a bunch of mice squeaking when the boat is in a seaway? A down side is apparently the bottles start crushing from water pressure as the sinking boat settles.
Some say to take out a second mortgage on your house and purchase Inter-Galactic closed cell foam built to NASA specs.
Some say best to use the blue foam found at the home improvement stores.
Use of Styrofoam usually starts a debate. But, folks report this foam has kept their docks afloat for decades though in direct contact with the water. That's good enough for me to rely on the material if the hull gets holed.
One Internet forum pundit claims that in a seaway the Styrofoam will rub against boat structures and bbs of Stryrofoam will be spawned. If so then this could create bilge pump clogging issues if a good strainer not employed. I glued the styrofoam blocks together so at least they won't be rubbing against each other. While true that gasoline will melt Styrofoam, if gas gets to areas where my foam is installed, I have much bigger problems (such as a very big boom) than melted foam. A 22' sailboat I owned had a large block of Styrofoam under the cockpit and v-berth for flotation and I experienced no annoying aspects of this material though frequently getting wacked by items being stowed.
Three coats of water proofing epoxy was applied to the longitudinal bulkheads and their cavities before the foam was installed. I left flotation out of the cavities straddling the keel line as they are the low points in the bilge and I wanted to ensure that water is not restricted in its flow aft. I cut limber holes in the longitudinal bulkheads to ensure water flows to the keel area.
In addition to the still to be installed flotation foam under the cockpit sole, I will probably stuff some foam under the v-berth. Considering that she is a woodenboat and along with the flotation, she should stay afloat when swamped but I know not whether she will stay upright or turn turtle. The ideal location of flotation from a stability standpoint is near the sheer line but not practical from a space nor appearance standpoint. But then again, the foam in the torsion box foredeck and the pilot house are mounted at or above the sheer line, thus In the worst case flooding I visualize the boat laying on her beam ends but not turning turtle. In fact the designer put foam flotation only under the cockpit sole which may allow the boat to sink some thus perhaps keeping her upright. I speculate that my additional foam my reduce engine noise transmission through the area under the pilot house sole.
My thoughts on a flooded Bluejacket's stability lack any empirical basis and reflect the speculations of an amateur. Anyhow, if I hole the hull I shall report back to you (assuming I don't drown) how the swamped boat behaved.
Edit: 03/30/2012. A 30' Scarab with two guys on board was recently fishing in the Gulf of Mexico off Texas when the boat starting taking on water and in-spite of multiple bilge pumps, sank. The guys had on life jackets and floated together for 30 hours until one started succumbing to hyperthermia. One swam several miles to an oil platform and summoned help but too late as hyperthermia claimed his friend. Had the boat stayed afloat and had an accessible area that allowed the guys to get out of the water, perhaps a life would have been saved. If a boat's displacement and practical space allows installation of flotation, omission of same can be a life ending error.
Cabin sole flotation.
I drove myself crazy studying the issue of what type of foam to use. Some say use two part pourable foam. Others say don't pour it if you don't have an ideal temperature and humidity environment during the pour. Others say poured foam can trap moisture.
Some say use empty and capped plastic bottles. Will this sound like a bunch of mice squeaking when the boat is in a seaway? A down side is apparently the bottles start crushing from water pressure as the sinking boat settles.
Some say to take out a second mortgage on your house and purchase Inter-Galactic closed cell foam built to NASA specs.
Some say best to use the blue foam found at the home improvement stores.
Use of Styrofoam usually starts a debate. But, folks report this foam has kept their docks afloat for decades though in direct contact with the water. That's good enough for me to rely on the material if the hull gets holed.
One Internet forum pundit claims that in a seaway the Styrofoam will rub against boat structures and bbs of Stryrofoam will be spawned. If so then this could create bilge pump clogging issues if a good strainer not employed. I glued the styrofoam blocks together so at least they won't be rubbing against each other. While true that gasoline will melt Styrofoam, if gas gets to areas where my foam is installed, I have much bigger problems (such as a very big boom) than melted foam. A 22' sailboat I owned had a large block of Styrofoam under the cockpit and v-berth for flotation and I experienced no annoying aspects of this material though frequently getting wacked by items being stowed.
Three coats of water proofing epoxy was applied to the longitudinal bulkheads and their cavities before the foam was installed. I left flotation out of the cavities straddling the keel line as they are the low points in the bilge and I wanted to ensure that water is not restricted in its flow aft. I cut limber holes in the longitudinal bulkheads to ensure water flows to the keel area.
In addition to the still to be installed flotation foam under the cockpit sole, I will probably stuff some foam under the v-berth. Considering that she is a woodenboat and along with the flotation, she should stay afloat when swamped but I know not whether she will stay upright or turn turtle. The ideal location of flotation from a stability standpoint is near the sheer line but not practical from a space nor appearance standpoint. But then again, the foam in the torsion box foredeck and the pilot house are mounted at or above the sheer line, thus In the worst case flooding I visualize the boat laying on her beam ends but not turning turtle. In fact the designer put foam flotation only under the cockpit sole which may allow the boat to sink some thus perhaps keeping her upright. I speculate that my additional foam my reduce engine noise transmission through the area under the pilot house sole.
My thoughts on a flooded Bluejacket's stability lack any empirical basis and reflect the speculations of an amateur. Anyhow, if I hole the hull I shall report back to you (assuming I don't drown) how the swamped boat behaved.
Edit: 03/30/2012. A 30' Scarab with two guys on board was recently fishing in the Gulf of Mexico off Texas when the boat starting taking on water and in-spite of multiple bilge pumps, sank. The guys had on life jackets and floated together for 30 hours until one started succumbing to hyperthermia. One swam several miles to an oil platform and summoned help but too late as hyperthermia claimed his friend. Had the boat stayed afloat and had an accessible area that allowed the guys to get out of the water, perhaps a life would have been saved. If a boat's displacement and practical space allows installation of flotation, omission of same can be a life ending error.