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Carlsboats
09-24-2000, 06:30 PM
Looking for a source of supply for inflatable tanks to use for flotation in a 19' keel/C.B. day sailer which, like the Fish boatsd and H 12 1/2's, is not self bailing.. Ideally, would put
V-shaped tank(s) into forepeak and some additonal flotation into lazarette. Does anyone offer these, stock or custom?

Carlsboats
09-24-2000, 06:30 PM
Looking for a source of supply for inflatable tanks to use for flotation in a 19' keel/C.B. day sailer which, like the Fish boatsd and H 12 1/2's, is not self bailing.. Ideally, would put
V-shaped tank(s) into forepeak and some additonal flotation into lazarette. Does anyone offer these, stock or custom?

Carlsboats
09-24-2000, 06:30 PM
Looking for a source of supply for inflatable tanks to use for flotation in a 19' keel/C.B. day sailer which, like the Fish boatsd and H 12 1/2's, is not self bailing.. Ideally, would put
V-shaped tank(s) into forepeak and some additonal flotation into lazarette. Does anyone offer these, stock or custom?

TomRobb
09-25-2000, 10:42 AM
Kayak/canoe dealers and catalogs have V shaped air bags. I've used truck tire innertubes in places where they don't show. You can get rapaired ones cheap from truck tire dealers. They're not pretty but they hold a lot of air and will form to fit a space. More or less.

TomRobb
09-25-2000, 10:42 AM
Kayak/canoe dealers and catalogs have V shaped air bags. I've used truck tire innertubes in places where they don't show. You can get rapaired ones cheap from truck tire dealers. They're not pretty but they hold a lot of air and will form to fit a space. More or less.

TomRobb
09-25-2000, 10:42 AM
Kayak/canoe dealers and catalogs have V shaped air bags. I've used truck tire innertubes in places where they don't show. You can get rapaired ones cheap from truck tire dealers. They're not pretty but they hold a lot of air and will form to fit a space. More or less.

Evan Showell
10-08-2000, 08:13 AM
Here's a tip from the plastic dingy racing folks (sailing Jet 14s out of the Hunterdon Sailing Club on Spruce Run Res. in Northwestern N.J.) -- empty plastic soda bottles with top screwed on tight make good, cheap flotation. Obviously, they won't form fit a space, but they don't absorb water like some foams and they're cheap. Thought I'd pass that one along.

Evan Showell
10-08-2000, 08:13 AM
Here's a tip from the plastic dingy racing folks (sailing Jet 14s out of the Hunterdon Sailing Club on Spruce Run Res. in Northwestern N.J.) -- empty plastic soda bottles with top screwed on tight make good, cheap flotation. Obviously, they won't form fit a space, but they don't absorb water like some foams and they're cheap. Thought I'd pass that one along.

Evan Showell
10-08-2000, 08:13 AM
Here's a tip from the plastic dingy racing folks (sailing Jet 14s out of the Hunterdon Sailing Club on Spruce Run Res. in Northwestern N.J.) -- empty plastic soda bottles with top screwed on tight make good, cheap flotation. Obviously, they won't form fit a space, but they don't absorb water like some foams and they're cheap. Thought I'd pass that one along.

Charlie J
10-08-2000, 11:51 AM
and if you run a bead of liquid nail or silicone around each of the jugs, they'll stick together and they won't rattle around either. Got that tip from a phone conversation with someone at the Gougeon's.

Charlie J
10-08-2000, 11:51 AM
and if you run a bead of liquid nail or silicone around each of the jugs, they'll stick together and they won't rattle around either. Got that tip from a phone conversation with someone at the Gougeon's.

Charlie J
10-08-2000, 11:51 AM
and if you run a bead of liquid nail or silicone around each of the jugs, they'll stick together and they won't rattle around either. Got that tip from a phone conversation with someone at the Gougeon's.

Wayne Jeffers
10-08-2000, 12:24 PM
To veer slightly off-topic --

Since the foam-in-place foam is rather expensive, I've wondered whether some empty 2-liter bottles pre-filling the space, with foam poured over and around them, wouldn't effectively stretch the foam. Of course, you would have to come up with a way to prevent the bottles from floating until the foam hardened.

But with the recent mentions in this forum of foams absorbing water, and the prospect of moisture trapped in a substantially sealed compartment inducing rot, I've largely decided against using this type foam again myself.

I've long believed that water is much easier to keep in (where its not wanted) than it is to keep out. I mistakenly thought that the foam would effectively exclude moisture/water.

Wayne

Wayne Jeffers
10-08-2000, 12:24 PM
To veer slightly off-topic --

Since the foam-in-place foam is rather expensive, I've wondered whether some empty 2-liter bottles pre-filling the space, with foam poured over and around them, wouldn't effectively stretch the foam. Of course, you would have to come up with a way to prevent the bottles from floating until the foam hardened.

But with the recent mentions in this forum of foams absorbing water, and the prospect of moisture trapped in a substantially sealed compartment inducing rot, I've largely decided against using this type foam again myself.

I've long believed that water is much easier to keep in (where its not wanted) than it is to keep out. I mistakenly thought that the foam would effectively exclude moisture/water.

Wayne

Wayne Jeffers
10-08-2000, 12:24 PM
To veer slightly off-topic --

Since the foam-in-place foam is rather expensive, I've wondered whether some empty 2-liter bottles pre-filling the space, with foam poured over and around them, wouldn't effectively stretch the foam. Of course, you would have to come up with a way to prevent the bottles from floating until the foam hardened.

But with the recent mentions in this forum of foams absorbing water, and the prospect of moisture trapped in a substantially sealed compartment inducing rot, I've largely decided against using this type foam again myself.

I've long believed that water is much easier to keep in (where its not wanted) than it is to keep out. I mistakenly thought that the foam would effectively exclude moisture/water.

Wayne

Todd Bradshaw
10-08-2000, 12:32 PM
Pour-in foam also gives-off a lot of heat as it expands. It might melt the bottles.

Todd Bradshaw
10-08-2000, 12:32 PM
Pour-in foam also gives-off a lot of heat as it expands. It might melt the bottles.

Todd Bradshaw
10-08-2000, 12:32 PM
Pour-in foam also gives-off a lot of heat as it expands. It might melt the bottles.

Ed Harrow
10-10-2000, 12:23 PM
A couple of my friends are big into the airplane scene and make the obligatory flight out to Oshkosh (sp?)by-gosh. This year they met an individual who flew his ultralight up from South America.

He was concerned that should he drop into the Gulf his ultralight would sink nearly as a stone... What to do? Fill up all the empty spaces (wing structure, etc) with very thouroughly inflated condoms. Must have been interesting at customs.

I'd be very leary of using something like soda bottles, the pressure on them as they drop beneath the surface could collapse them much sooner than you might expect.

Ed Harrow
10-10-2000, 12:23 PM
A couple of my friends are big into the airplane scene and make the obligatory flight out to Oshkosh (sp?)by-gosh. This year they met an individual who flew his ultralight up from South America.

He was concerned that should he drop into the Gulf his ultralight would sink nearly as a stone... What to do? Fill up all the empty spaces (wing structure, etc) with very thouroughly inflated condoms. Must have been interesting at customs.

I'd be very leary of using something like soda bottles, the pressure on them as they drop beneath the surface could collapse them much sooner than you might expect.

Ed Harrow
10-10-2000, 12:23 PM
A couple of my friends are big into the airplane scene and make the obligatory flight out to Oshkosh (sp?)by-gosh. This year they met an individual who flew his ultralight up from South America.

He was concerned that should he drop into the Gulf his ultralight would sink nearly as a stone... What to do? Fill up all the empty spaces (wing structure, etc) with very thouroughly inflated condoms. Must have been interesting at customs.

I'd be very leary of using something like soda bottles, the pressure on them as they drop beneath the surface could collapse them much sooner than you might expect.

Wayne Jeffers
10-10-2000, 12:39 PM
I dunno, Ed.

The soda bottles can withstand the internal pressure from the carbonated beverage.

I suspect that if the caps are on tight, by the time they reach a depth where the external pressure ruptures them, the boat would have much bigger problems anyway.

It's all hypothetical as far as I'm concerned, though.

Now that condom thing . . .

Wayne

Wayne Jeffers
10-10-2000, 12:39 PM
I dunno, Ed.

The soda bottles can withstand the internal pressure from the carbonated beverage.

I suspect that if the caps are on tight, by the time they reach a depth where the external pressure ruptures them, the boat would have much bigger problems anyway.

It's all hypothetical as far as I'm concerned, though.

Now that condom thing . . .

Wayne

Wayne Jeffers
10-10-2000, 12:39 PM
I dunno, Ed.

The soda bottles can withstand the internal pressure from the carbonated beverage.

I suspect that if the caps are on tight, by the time they reach a depth where the external pressure ruptures them, the boat would have much bigger problems anyway.

It's all hypothetical as far as I'm concerned, though.

Now that condom thing . . .

Wayne

Henri
10-14-2000, 03:02 PM
A replacement bladder for a water system pressure tank might fit. The Sta-Rite of housefold size is 17 gal which would be what, about 135# floatation. Also, try one of your local packaging suppliers for foldable 5 gal water/liquid jugs, each will be 5 gallons or about 40# flotation. I think the camping retailers sell them abiet mucho$.

Henri
10-14-2000, 03:02 PM
A replacement bladder for a water system pressure tank might fit. The Sta-Rite of housefold size is 17 gal which would be what, about 135# floatation. Also, try one of your local packaging suppliers for foldable 5 gal water/liquid jugs, each will be 5 gallons or about 40# flotation. I think the camping retailers sell them abiet mucho$.

Henri
10-14-2000, 03:02 PM
A replacement bladder for a water system pressure tank might fit. The Sta-Rite of housefold size is 17 gal which would be what, about 135# floatation. Also, try one of your local packaging suppliers for foldable 5 gal water/liquid jugs, each will be 5 gallons or about 40# flotation. I think the camping retailers sell them abiet mucho$.

MikeGardner
10-14-2000, 07:05 PM
Plastic soda bottles are designed only for internal pressure and will collapse easily, cap one and the submerse it and see.Also, the plastic used is thermo-formed...basically they are moulded as a stubby and then blown up while hot.Take one and hold it over a steaming pot..the thin midsection will shrivel and shrink.
I like the condom Idea but it would only be a shortterm plan due to the fragility of latex, they are designed as thin as possible..or so they say, and the stink of that stuff on them would be somewhat a turnoff ...for me anyway.The urethane foam sold at hardware stores is available in a low-expansion version. Whatever you try, I would plan on removal so if it deteriorates you can try another angle without major structural work.
I have seen fuel and water tanks, as well as dock floats, built by hot welding plastic. A dock manufacturer using this method could build you a set of tanks probably as thin as 1/8" thick. Then just strap them in or buld around them.
Good luck..keep us posted..mg

[This message has been edited by MikeGardner (edited 10-14-2000).]

MikeGardner
10-14-2000, 07:05 PM
Plastic soda bottles are designed only for internal pressure and will collapse easily, cap one and the submerse it and see.Also, the plastic used is thermo-formed...basically they are moulded as a stubby and then blown up while hot.Take one and hold it over a steaming pot..the thin midsection will shrivel and shrink.
I like the condom Idea but it would only be a shortterm plan due to the fragility of latex, they are designed as thin as possible..or so they say, and the stink of that stuff on them would be somewhat a turnoff ...for me anyway.The urethane foam sold at hardware stores is available in a low-expansion version. Whatever you try, I would plan on removal so if it deteriorates you can try another angle without major structural work.
I have seen fuel and water tanks, as well as dock floats, built by hot welding plastic. A dock manufacturer using this method could build you a set of tanks probably as thin as 1/8" thick. Then just strap them in or buld around them.
Good luck..keep us posted..mg

[This message has been edited by MikeGardner (edited 10-14-2000).]

MikeGardner
10-14-2000, 07:05 PM
Plastic soda bottles are designed only for internal pressure and will collapse easily, cap one and the submerse it and see.Also, the plastic used is thermo-formed...basically they are moulded as a stubby and then blown up while hot.Take one and hold it over a steaming pot..the thin midsection will shrivel and shrink.
I like the condom Idea but it would only be a shortterm plan due to the fragility of latex, they are designed as thin as possible..or so they say, and the stink of that stuff on them would be somewhat a turnoff ...for me anyway.The urethane foam sold at hardware stores is available in a low-expansion version. Whatever you try, I would plan on removal so if it deteriorates you can try another angle without major structural work.
I have seen fuel and water tanks, as well as dock floats, built by hot welding plastic. A dock manufacturer using this method could build you a set of tanks probably as thin as 1/8" thick. Then just strap them in or buld around them.
Good luck..keep us posted..mg

[This message has been edited by MikeGardner (edited 10-14-2000).]

Oyvind Snibsoer
10-15-2000, 06:34 AM
Sorry, this discussion just got me started on some applied physics:

If a perfectly flexible container filled with an ideal gas is submerged 1/2 meter below the surface, the increase in pressure = .05 bar = 5%. The volume is then decreased by same amount. For a 1 liter perfectly flexible soda bottle, initially filled at surface pressure of 1 bar, the volume when submerged would then be (1 liter/1.05 bar absolute pressure)=0,95 liter. At 1 meter submerged the volume would be .9 liter and at 10 meters (2 bars absolute pressure) the volume would be 1/2 the original volume. The volume is again halved at 30 meters (4 bars abs.pressure) and again at 70 meters (8 bars abs.pressure) etc. The bottle still cannot break until the cap area is deformed, because the internal pressure is equal to the external pressure, minus some factor imposed by the mechanical rigidity of the bottle's walls. If a 19' boat is submerged much beyond 2 meters, then it's definitely sinking, and you didn't put in enough flotation, but those soda bottles won't pop until it hits the seabed at 500 meters+.

(If we assume that, in a 1 liter bottle where the whole bottle except the cap area is perfectly flexible, and the cap area has a volume of 2 cl=.02 liters, then the cap won't deform until the bottle's reduced volume < .02 liters. This will happen at a pressure greater than (1 liter/.02 liters) = 50 bar absolute = 490 meters.)


[This message has been edited by Øyvind Snibsøer (edited 10-15-2000).]

Oyvind Snibsoer
10-15-2000, 06:34 AM
Sorry, this discussion just got me started on some applied physics:

If a perfectly flexible container filled with an ideal gas is submerged 1/2 meter below the surface, the increase in pressure = .05 bar = 5%. The volume is then decreased by same amount. For a 1 liter perfectly flexible soda bottle, initially filled at surface pressure of 1 bar, the volume when submerged would then be (1 liter/1.05 bar absolute pressure)=0,95 liter. At 1 meter submerged the volume would be .9 liter and at 10 meters (2 bars absolute pressure) the volume would be 1/2 the original volume. The volume is again halved at 30 meters (4 bars abs.pressure) and again at 70 meters (8 bars abs.pressure) etc. The bottle still cannot break until the cap area is deformed, because the internal pressure is equal to the external pressure, minus some factor imposed by the mechanical rigidity of the bottle's walls. If a 19' boat is submerged much beyond 2 meters, then it's definitely sinking, and you didn't put in enough flotation, but those soda bottles won't pop until it hits the seabed at 500 meters+.

(If we assume that, in a 1 liter bottle where the whole bottle except the cap area is perfectly flexible, and the cap area has a volume of 2 cl=.02 liters, then the cap won't deform until the bottle's reduced volume < .02 liters. This will happen at a pressure greater than (1 liter/.02 liters) = 50 bar absolute = 490 meters.)


[This message has been edited by Øyvind Snibsøer (edited 10-15-2000).]

Oyvind Snibsoer
10-15-2000, 06:34 AM
Sorry, this discussion just got me started on some applied physics:

If a perfectly flexible container filled with an ideal gas is submerged 1/2 meter below the surface, the increase in pressure = .05 bar = 5%. The volume is then decreased by same amount. For a 1 liter perfectly flexible soda bottle, initially filled at surface pressure of 1 bar, the volume when submerged would then be (1 liter/1.05 bar absolute pressure)=0,95 liter. At 1 meter submerged the volume would be .9 liter and at 10 meters (2 bars absolute pressure) the volume would be 1/2 the original volume. The volume is again halved at 30 meters (4 bars abs.pressure) and again at 70 meters (8 bars abs.pressure) etc. The bottle still cannot break until the cap area is deformed, because the internal pressure is equal to the external pressure, minus some factor imposed by the mechanical rigidity of the bottle's walls. If a 19' boat is submerged much beyond 2 meters, then it's definitely sinking, and you didn't put in enough flotation, but those soda bottles won't pop until it hits the seabed at 500 meters+.

(If we assume that, in a 1 liter bottle where the whole bottle except the cap area is perfectly flexible, and the cap area has a volume of 2 cl=.02 liters, then the cap won't deform until the bottle's reduced volume < .02 liters. This will happen at a pressure greater than (1 liter/.02 liters) = 50 bar absolute = 490 meters.)


[This message has been edited by Øyvind Snibsøer (edited 10-15-2000).]

rbgarr
10-15-2000, 02:28 PM
Slightly off-topic story follows:

One of my first jobs building boats was putting fiberglass duck hunting boat together. These were 13' long, narrow low-sided hulls with a high coaminged deck glued and pop-rivetted (!) together along an outboard flange. Of course the flange was covered with a lovely (sarcasm, here) vinyl 'rubrail'. The boats were painted in a flat camo green. I thought they looked like miniature C.S.S. Virginia's (or Merrimac's for the Yanks among us).

Anyhow, there were two compartments for foam flotation in these boats, one forward and one aft, and we used a two part product that would expand when mixed and poured in place. My first day I was getting 'training' from someone whose accent was not real clear to me and I misunderstood the proportions of the mix. I poured the foam mixture, lowered the deck on with the glue and clamped it down all along the edge (quality control took second place to speed here) and went off to another part of the factory off to work on fabricating more parts. Later I went back to check on the glue, so I could start drilling and pop-rivetting. The boat looked like one of those washing machine jokes where too much detergent has been put in and there's suds-foam flooding the basement! Except these bubbles were hard, sticky and hot to the touch with the bow of a boat sticking out and not much else in view.

Don't use that stuff in a wood boat...what a job it was to clean up!

rbgarr
10-15-2000, 02:28 PM
Slightly off-topic story follows:

One of my first jobs building boats was putting fiberglass duck hunting boat together. These were 13' long, narrow low-sided hulls with a high coaminged deck glued and pop-rivetted (!) together along an outboard flange. Of course the flange was covered with a lovely (sarcasm, here) vinyl 'rubrail'. The boats were painted in a flat camo green. I thought they looked like miniature C.S.S. Virginia's (or Merrimac's for the Yanks among us).

Anyhow, there were two compartments for foam flotation in these boats, one forward and one aft, and we used a two part product that would expand when mixed and poured in place. My first day I was getting 'training' from someone whose accent was not real clear to me and I misunderstood the proportions of the mix. I poured the foam mixture, lowered the deck on with the glue and clamped it down all along the edge (quality control took second place to speed here) and went off to another part of the factory off to work on fabricating more parts. Later I went back to check on the glue, so I could start drilling and pop-rivetting. The boat looked like one of those washing machine jokes where too much detergent has been put in and there's suds-foam flooding the basement! Except these bubbles were hard, sticky and hot to the touch with the bow of a boat sticking out and not much else in view.

Don't use that stuff in a wood boat...what a job it was to clean up!

rbgarr
10-15-2000, 02:28 PM
Slightly off-topic story follows:

One of my first jobs building boats was putting fiberglass duck hunting boat together. These were 13' long, narrow low-sided hulls with a high coaminged deck glued and pop-rivetted (!) together along an outboard flange. Of course the flange was covered with a lovely (sarcasm, here) vinyl 'rubrail'. The boats were painted in a flat camo green. I thought they looked like miniature C.S.S. Virginia's (or Merrimac's for the Yanks among us).

Anyhow, there were two compartments for foam flotation in these boats, one forward and one aft, and we used a two part product that would expand when mixed and poured in place. My first day I was getting 'training' from someone whose accent was not real clear to me and I misunderstood the proportions of the mix. I poured the foam mixture, lowered the deck on with the glue and clamped it down all along the edge (quality control took second place to speed here) and went off to another part of the factory off to work on fabricating more parts. Later I went back to check on the glue, so I could start drilling and pop-rivetting. The boat looked like one of those washing machine jokes where too much detergent has been put in and there's suds-foam flooding the basement! Except these bubbles were hard, sticky and hot to the touch with the bow of a boat sticking out and not much else in view.

Don't use that stuff in a wood boat...what a job it was to clean up!

Henri
10-16-2000, 04:33 PM
This is a good subject.
For bladders, try the same entities that make fuel cells for race cars; these same people make inflatable water tanks for the military that are deliverable by helicopter to conflict sites. These bladders can be pnuematically inflated.
I ran into an entity named Sealed Air Corporation that specializes in protective packaging. They have a system and process for making low density foam (ie, 1#/ft3)structures in place, within trash bags and the like. Go to www.sealedair.com, (http://www.sealedair.com,) then check out specifically thier INSTAPAK system.If this will work, and I think it will, find an entity in your neighborhood who uses it and beg for some. You've probably seen this stuff, its typically ysed for delicate electronics and the like. The neat part about this is that it has a vapor/water barrier, fits to your space, and does not stick to your structure, so you can shop it up and take it out quite easily.

Henri
10-16-2000, 04:33 PM
This is a good subject.
For bladders, try the same entities that make fuel cells for race cars; these same people make inflatable water tanks for the military that are deliverable by helicopter to conflict sites. These bladders can be pnuematically inflated.
I ran into an entity named Sealed Air Corporation that specializes in protective packaging. They have a system and process for making low density foam (ie, 1#/ft3)structures in place, within trash bags and the like. Go to www.sealedair.com, (http://www.sealedair.com,) then check out specifically thier INSTAPAK system.If this will work, and I think it will, find an entity in your neighborhood who uses it and beg for some. You've probably seen this stuff, its typically ysed for delicate electronics and the like. The neat part about this is that it has a vapor/water barrier, fits to your space, and does not stick to your structure, so you can shop it up and take it out quite easily.

Henri
10-16-2000, 04:33 PM
This is a good subject.
For bladders, try the same entities that make fuel cells for race cars; these same people make inflatable water tanks for the military that are deliverable by helicopter to conflict sites. These bladders can be pnuematically inflated.
I ran into an entity named Sealed Air Corporation that specializes in protective packaging. They have a system and process for making low density foam (ie, 1#/ft3)structures in place, within trash bags and the like. Go to www.sealedair.com, (http://www.sealedair.com,) then check out specifically thier INSTAPAK system.If this will work, and I think it will, find an entity in your neighborhood who uses it and beg for some. You've probably seen this stuff, its typically ysed for delicate electronics and the like. The neat part about this is that it has a vapor/water barrier, fits to your space, and does not stick to your structure, so you can shop it up and take it out quite easily.

Dave R
10-17-2000, 08:36 AM
My co-worker and I were discussing this and he had a thought about using the 1L soda bottles. Cap them at sea level on a below 0F day. Then, when they warm up in the spring they'd be under a slight positive pressure inside. This would possibly buy you a few more cm before they collapse as well as a little more bouyancy.

Dave R
10-17-2000, 08:36 AM
My co-worker and I were discussing this and he had a thought about using the 1L soda bottles. Cap them at sea level on a below 0F day. Then, when they warm up in the spring they'd be under a slight positive pressure inside. This would possibly buy you a few more cm before they collapse as well as a little more bouyancy.

Dave R
10-17-2000, 08:36 AM
My co-worker and I were discussing this and he had a thought about using the 1L soda bottles. Cap them at sea level on a below 0F day. Then, when they warm up in the spring they'd be under a slight positive pressure inside. This would possibly buy you a few more cm before they collapse as well as a little more bouyancy.

Wayne Jeffers
10-17-2000, 08:51 AM
An impressive analysis, Øyvind.

Empirically, capped empty plastic soda bottles will successfully withstand my weight when I try to flatten them before placing them in the trash. I project from this information that the water pressure necessary to cause them to fail would require a great depth. A depth at which I think, as you pointed out, the amount of floatation will have already proven inadequate.

Thank you for quantifying.

Wayne

Wayne Jeffers
10-17-2000, 08:51 AM
An impressive analysis, Øyvind.

Empirically, capped empty plastic soda bottles will successfully withstand my weight when I try to flatten them before placing them in the trash. I project from this information that the water pressure necessary to cause them to fail would require a great depth. A depth at which I think, as you pointed out, the amount of floatation will have already proven inadequate.

Thank you for quantifying.

Wayne

Wayne Jeffers
10-17-2000, 08:51 AM
An impressive analysis, Øyvind.

Empirically, capped empty plastic soda bottles will successfully withstand my weight when I try to flatten them before placing them in the trash. I project from this information that the water pressure necessary to cause them to fail would require a great depth. A depth at which I think, as you pointed out, the amount of floatation will have already proven inadequate.

Thank you for quantifying.

Wayne

Todd Bradshaw
10-17-2000, 12:01 PM
I dug around in the garage and found a flotation gizmo that I salvaged from a damaged LaserII about ten years ago. It is a polyethylene cube, very much like the Reliance brand of water cubes that campers use. It holds 20 liters (about 11.5" x 11.5" x 10.5" tall) with no handles and a simple screw-on cap.
It says on it that it was built by Cousins-Currie Limited in Woodbridge, Ontario. As I recall, they were loose and three or four were distributed throughout the hull, kept in place by the internal bulkheads and/or hull shape. It's not really any heavier-duty than the good quality water cubes, so I don't know why they wouldn't work, though I might try to replace the spigot with a simple cap for security.

Todd Bradshaw
10-17-2000, 12:01 PM
I dug around in the garage and found a flotation gizmo that I salvaged from a damaged LaserII about ten years ago. It is a polyethylene cube, very much like the Reliance brand of water cubes that campers use. It holds 20 liters (about 11.5" x 11.5" x 10.5" tall) with no handles and a simple screw-on cap.
It says on it that it was built by Cousins-Currie Limited in Woodbridge, Ontario. As I recall, they were loose and three or four were distributed throughout the hull, kept in place by the internal bulkheads and/or hull shape. It's not really any heavier-duty than the good quality water cubes, so I don't know why they wouldn't work, though I might try to replace the spigot with a simple cap for security.

Todd Bradshaw
10-17-2000, 12:01 PM
I dug around in the garage and found a flotation gizmo that I salvaged from a damaged LaserII about ten years ago. It is a polyethylene cube, very much like the Reliance brand of water cubes that campers use. It holds 20 liters (about 11.5" x 11.5" x 10.5" tall) with no handles and a simple screw-on cap.
It says on it that it was built by Cousins-Currie Limited in Woodbridge, Ontario. As I recall, they were loose and three or four were distributed throughout the hull, kept in place by the internal bulkheads and/or hull shape. It's not really any heavier-duty than the good quality water cubes, so I don't know why they wouldn't work, though I might try to replace the spigot with a simple cap for security.

TomRobb
10-17-2000, 12:28 PM
Yes, an interesting analysis. However, if your boat is below the surface, the system has already failed, and crush depth is irrelevent.

TomRobb
10-17-2000, 12:28 PM
Yes, an interesting analysis. However, if your boat is below the surface, the system has already failed, and crush depth is irrelevent.

TomRobb
10-17-2000, 12:28 PM
Yes, an interesting analysis. However, if your boat is below the surface, the system has already failed, and crush depth is irrelevent.

Henri
10-21-2000, 09:54 AM
The inflatable containers referred to earlier by myself and Todd Bradshaw are also made in the US by CCA (Container Coporation of America) and one I have is coded as being from a NJ facility.You can buy these from several mail order office supply and or machine shop supply houses, I think you can also find them on the web if you snoop around. They are commonly used for cooking oils and the like in the restaurant trade. Try restaurants for used ones. Oh, restuarant suppy houses also sell these things.
Another relatively low coast inflatable device would be the bag-in-the-box used by the soft drink industry. These bags are also available in relatively large sizes. the big company on the West coast is Scholle. Another company is Liqui-Box. there used to be a midwest manufacturer to the NW of Chicago. Look in Thomas Register for bag-in-box or call a soft drink bottling plant .

Henri
10-21-2000, 09:54 AM
The inflatable containers referred to earlier by myself and Todd Bradshaw are also made in the US by CCA (Container Coporation of America) and one I have is coded as being from a NJ facility.You can buy these from several mail order office supply and or machine shop supply houses, I think you can also find them on the web if you snoop around. They are commonly used for cooking oils and the like in the restaurant trade. Try restaurants for used ones. Oh, restuarant suppy houses also sell these things.
Another relatively low coast inflatable device would be the bag-in-the-box used by the soft drink industry. These bags are also available in relatively large sizes. the big company on the West coast is Scholle. Another company is Liqui-Box. there used to be a midwest manufacturer to the NW of Chicago. Look in Thomas Register for bag-in-box or call a soft drink bottling plant .

Henri
10-21-2000, 09:54 AM
The inflatable containers referred to earlier by myself and Todd Bradshaw are also made in the US by CCA (Container Coporation of America) and one I have is coded as being from a NJ facility.You can buy these from several mail order office supply and or machine shop supply houses, I think you can also find them on the web if you snoop around. They are commonly used for cooking oils and the like in the restaurant trade. Try restaurants for used ones. Oh, restuarant suppy houses also sell these things.
Another relatively low coast inflatable device would be the bag-in-the-box used by the soft drink industry. These bags are also available in relatively large sizes. the big company on the West coast is Scholle. Another company is Liqui-Box. there used to be a midwest manufacturer to the NW of Chicago. Look in Thomas Register for bag-in-box or call a soft drink bottling plant .

Ed Harrow
10-22-2000, 03:03 PM
In the end, the amount of flotation required is approx equal to the amount of non-buoyant
material (ballast, etc) in the boat. Given that water weighs approx 62 lbs/cubic foot (if I
remember correctly) a boat with 620 pounds of ballast and non-buouant material would
require approx 10 cubic feet of air (tho obviously the buoyancy of the wood should be
taken into account), and that's a significant volume in any boat. Also the flotation will
need to be secured such that the fastenings/attachments are up to the boat's desire (at such
time this flotation is needed) of dropping out from underneath.

I once was witness to the attempted self-salvage of a Herreshoff S-boat. A harness of six
55-gallon barrels was attached to the boat at low tide. As the tide rose, low and behold,
so did the boat, complete with the cheers of the participants and the observers. Then,
quite spectacularly, one barrel collapsed, followed in immeadiate order by the other five.
The calculations were redone, eight barrels were attached for the next, successful,
attempt.

Øyvind, nice work - I'm getting lazy in my old age

Ed Harrow
10-22-2000, 03:03 PM
In the end, the amount of flotation required is approx equal to the amount of non-buoyant
material (ballast, etc) in the boat. Given that water weighs approx 62 lbs/cubic foot (if I
remember correctly) a boat with 620 pounds of ballast and non-buouant material would
require approx 10 cubic feet of air (tho obviously the buoyancy of the wood should be
taken into account), and that's a significant volume in any boat. Also the flotation will
need to be secured such that the fastenings/attachments are up to the boat's desire (at such
time this flotation is needed) of dropping out from underneath.

I once was witness to the attempted self-salvage of a Herreshoff S-boat. A harness of six
55-gallon barrels was attached to the boat at low tide. As the tide rose, low and behold,
so did the boat, complete with the cheers of the participants and the observers. Then,
quite spectacularly, one barrel collapsed, followed in immeadiate order by the other five.
The calculations were redone, eight barrels were attached for the next, successful,
attempt.

Øyvind, nice work - I'm getting lazy in my old age

Ed Harrow
10-22-2000, 03:03 PM
In the end, the amount of flotation required is approx equal to the amount of non-buoyant
material (ballast, etc) in the boat. Given that water weighs approx 62 lbs/cubic foot (if I
remember correctly) a boat with 620 pounds of ballast and non-buouant material would
require approx 10 cubic feet of air (tho obviously the buoyancy of the wood should be
taken into account), and that's a significant volume in any boat. Also the flotation will
need to be secured such that the fastenings/attachments are up to the boat's desire (at such
time this flotation is needed) of dropping out from underneath.

I once was witness to the attempted self-salvage of a Herreshoff S-boat. A harness of six
55-gallon barrels was attached to the boat at low tide. As the tide rose, low and behold,
so did the boat, complete with the cheers of the participants and the observers. Then,
quite spectacularly, one barrel collapsed, followed in immeadiate order by the other five.
The calculations were redone, eight barrels were attached for the next, successful,
attempt.

Øyvind, nice work - I'm getting lazy in my old age

Ian McColgin
10-22-2000, 07:26 PM
Blowing air into tanks works. I raise a sunk lobster boat with nothing more comples than a few 55 gal drums open at one end, some slings, and an extra scuba tank.

But ramming a few dozen old coke bottles around is pretty inefficient. Even flat froms, like all the surplused architectural styrofoam in my firend's barge, is lucky to float out at about 50% space to contain the floatation vs. actual flotation. Bottles are even less efficient.

To keep usable space in the boat, I'd advocate either good construction to have air tanks or, if you want to float even when the hull looses integrity, which is a nice time to float, bite the bullet, pay the man a dollar, and get the foam.

For us larger boat types, there used to be an outfit that was making what amounted to an internal life raft. Pull a lanyard and CO2 would fill some bags strategically placed. I th ink they are out of business, and don't know whether no one wanted the product or whether it turned out not to work.

Oh yeah, we saltwater types usually think about 64#/cuft, but when you allow for safety-fudge factor and easy inthehead division, I usually go with 60#.

Whatever, keep the 'PFD'.

Ian McColgin
10-22-2000, 07:26 PM
Blowing air into tanks works. I raise a sunk lobster boat with nothing more comples than a few 55 gal drums open at one end, some slings, and an extra scuba tank.

But ramming a few dozen old coke bottles around is pretty inefficient. Even flat froms, like all the surplused architectural styrofoam in my firend's barge, is lucky to float out at about 50% space to contain the floatation vs. actual flotation. Bottles are even less efficient.

To keep usable space in the boat, I'd advocate either good construction to have air tanks or, if you want to float even when the hull looses integrity, which is a nice time to float, bite the bullet, pay the man a dollar, and get the foam.

For us larger boat types, there used to be an outfit that was making what amounted to an internal life raft. Pull a lanyard and CO2 would fill some bags strategically placed. I th ink they are out of business, and don't know whether no one wanted the product or whether it turned out not to work.

Oh yeah, we saltwater types usually think about 64#/cuft, but when you allow for safety-fudge factor and easy inthehead division, I usually go with 60#.

Whatever, keep the 'PFD'.

Ian McColgin
10-22-2000, 07:26 PM
Blowing air into tanks works. I raise a sunk lobster boat with nothing more comples than a few 55 gal drums open at one end, some slings, and an extra scuba tank.

But ramming a few dozen old coke bottles around is pretty inefficient. Even flat froms, like all the surplused architectural styrofoam in my firend's barge, is lucky to float out at about 50% space to contain the floatation vs. actual flotation. Bottles are even less efficient.

To keep usable space in the boat, I'd advocate either good construction to have air tanks or, if you want to float even when the hull looses integrity, which is a nice time to float, bite the bullet, pay the man a dollar, and get the foam.

For us larger boat types, there used to be an outfit that was making what amounted to an internal life raft. Pull a lanyard and CO2 would fill some bags strategically placed. I th ink they are out of business, and don't know whether no one wanted the product or whether it turned out not to work.

Oh yeah, we saltwater types usually think about 64#/cuft, but when you allow for safety-fudge factor and easy inthehead division, I usually go with 60#.

Whatever, keep the 'PFD'.

Oyvind Snibsoer
10-23-2000, 05:41 AM
Making inflatable tubes to fit in your boat yourself shouldn't really be that hard. The rubber covered fabric that liferafts and rubber dinghys are made of is as about as easy to glue as patching a bike tube. It only requires a bit more temperature and humidity control. Inflation may be provided by a CO2 or air filled tank (CO2 delivers more gas per storage volume since it's in a liquid state when stored). Lanyard operated tank valves, input (w/one-way valve) and relief valves (VERY important) may probably be had pretty cheap from a discarded liferaft if you contact a liferaft maintenance shop. They should also be able to help you with fabric and glue. Roll the tubes into "sausages" to fit where you want, and wrap them in canvas sewn together with something that will break when the tubes are inflated. Cheap low-pressure hose, such as used for pressurized air tools, may be used for connecting the tubes with the gas tank(s). Just make sure the tubes have room to expand.

Oyvind Snibsoer
10-23-2000, 05:41 AM
Making inflatable tubes to fit in your boat yourself shouldn't really be that hard. The rubber covered fabric that liferafts and rubber dinghys are made of is as about as easy to glue as patching a bike tube. It only requires a bit more temperature and humidity control. Inflation may be provided by a CO2 or air filled tank (CO2 delivers more gas per storage volume since it's in a liquid state when stored). Lanyard operated tank valves, input (w/one-way valve) and relief valves (VERY important) may probably be had pretty cheap from a discarded liferaft if you contact a liferaft maintenance shop. They should also be able to help you with fabric and glue. Roll the tubes into "sausages" to fit where you want, and wrap them in canvas sewn together with something that will break when the tubes are inflated. Cheap low-pressure hose, such as used for pressurized air tools, may be used for connecting the tubes with the gas tank(s). Just make sure the tubes have room to expand.

Oyvind Snibsoer
10-23-2000, 05:41 AM
Making inflatable tubes to fit in your boat yourself shouldn't really be that hard. The rubber covered fabric that liferafts and rubber dinghys are made of is as about as easy to glue as patching a bike tube. It only requires a bit more temperature and humidity control. Inflation may be provided by a CO2 or air filled tank (CO2 delivers more gas per storage volume since it's in a liquid state when stored). Lanyard operated tank valves, input (w/one-way valve) and relief valves (VERY important) may probably be had pretty cheap from a discarded liferaft if you contact a liferaft maintenance shop. They should also be able to help you with fabric and glue. Roll the tubes into "sausages" to fit where you want, and wrap them in canvas sewn together with something that will break when the tubes are inflated. Cheap low-pressure hose, such as used for pressurized air tools, may be used for connecting the tubes with the gas tank(s). Just make sure the tubes have room to expand.

redsail
10-28-2000, 09:48 PM
How about filling that space with ping-pong balls, or suffing those styrofoam packing peanuts into the plastic soda jugs. LOL

redsail
10-28-2000, 09:48 PM
How about filling that space with ping-pong balls, or suffing those styrofoam packing peanuts into the plastic soda jugs. LOL

redsail
10-28-2000, 09:48 PM
How about filling that space with ping-pong balls, or suffing those styrofoam packing peanuts into the plastic soda jugs. LOL

jeffery
10-29-2000, 10:30 PM
When working for a photo finisher I salvaged the plastic bottle ( some ridged but the bigger 5 gallon cubes colaspe into a stackable pyramids) I got a fairly good supply of washed out jugs but eventually the boss got more and more worried that I'd become a super fund site he would be responsible for so that ended that.
Jeffery

jeffery
10-29-2000, 10:30 PM
When working for a photo finisher I salvaged the plastic bottle ( some ridged but the bigger 5 gallon cubes colaspe into a stackable pyramids) I got a fairly good supply of washed out jugs but eventually the boss got more and more worried that I'd become a super fund site he would be responsible for so that ended that.
Jeffery

jeffery
10-29-2000, 10:30 PM
When working for a photo finisher I salvaged the plastic bottle ( some ridged but the bigger 5 gallon cubes colaspe into a stackable pyramids) I got a fairly good supply of washed out jugs but eventually the boss got more and more worried that I'd become a super fund site he would be responsible for so that ended that.
Jeffery