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holding tank hand pump
DSK wrote:
Terry Spragg wrote: I can use a bicycle pump or similar to evacuate my holding tank offshore. I close both air vents, open the sea valve, and pump up the holding tank with air. This is a really bad idea. The question is not *if* the tank will blow up, but when. Woudn't that depend on system parameters and design? If one pound pressure won't do 'it' in my system, then there is something else to look at. The highest standard for marine tanks (including fuel BTW) and associated fittings is .5 psi overpressure. Most are not built to withstand even that much. Who's fault or design is that? If you really have been doing this Terry, you've been very lucky (and so have your neighbors). Fresh Breezes- Doug King Amen to that;-) I would likely not try to shoot PWC's with poo from the deck cannon, but the thought is so entertaining, I just might be tempted after dinner and drinks on the hook. Keep clear, PWC fools! You ought to spread the word that this is a viable system, maybe it will keep them away if a story, even a bogus story should be told... I built the tank out of 1/4" thick polyester and glass, except for the top, which is more like 3/16" thick, with an epoxy lining. I do not do this deck cannon blow regularly, but did do it to see if it would work when it was new and clean. It works. After it has aged a few more years, when the joker is a little older, I intend to clean it out as well as can be done, and then I will see where the weak link is, just for fun, up to about 5 pounds just for the sake of curiosity. I am quit certain that the joker or a rubber bellows hose between the head and the Seacock will be the part that blows up eventually, even without 'dive pressure' testing. The tank itself is not rated, and has not been tested to destruction, so I can't say, yet. It can take about a 10 foot head of pressure. I do check for leaks under moderate pressure before launch, and would expect to detect seepage before total failure in the joker, which I will not change until I must. Moderate pressure is about 10 pounds force on the head pump handle, which, by thumb, equates with about 2 pounds system pressure. It would be possible for a normal physique to apply perhaps 50 pounds force, or 10 lbs system overpressure. That would be very scary, but I doubt anybody could be so stupid as to actually lean that hard on the handle, as someone suggests must have been done, since he said it blew up. When I got the boat, the joker was the wrong one, and leaked. That is where I started. I wonder how many others are co-existing with a dodgy setup, improperly maintained? Usually I 'blow tanks' via the head seacock which is only about an inch below the waterline, so the pressure required in too low to register on any gague that I have. The top quarter of the holding tank runs out without assistance, anyway, on starboard tack It does work, and that logic stands in opposition, apparently, only to fear on the part of the operator who prefers to ignore head maintenance. After some of the messes I have cleaned up, a little poo from folks I know is of small consequence. They are all healthy, and I have developed a plumber's stomach, having raised a few kids from diapers to college, looking after an old relative or two, and having fixed a few heads, at sea and ashore, in the last 50 years. Not to wax too political, but so many people seem to be so unreasonably squeamish about such little things, akin to so many who seem so concerned with miniscule calculated risks in both physical safety and so called 'security.' There is, and can be, no perfect safety or security system. I cannot understand how such people ever get into thier boats for a sail, or thier cars to drive in traffic, or even get to sleep at night, given that it is so easy to blow up an entire city block with just a gallon or two of gasoline. It seems the stock market must respond too easily to minor rumours of 'terror' attacks on stock values, could this be a popular tool amongst market manipulators? Ask any farmer about animal husbandry, now there's a messy business. Do we all forget how recently is was that most folks a generation or two ago worked in shall we say, primitive conditions? How soon our expectations have risen, and how far. How quickly too, our modern conveniences have spoiled so many waterways for those who appreciate nature's way of sun, wind and water. Could it be that those who must have power boats are afraid to see close up and slowly the water over which they now travel so quickly? We evolved in natural healthy 'filth' unimaginable to modern youth, and it did not stop us from prospering, perhaps too much. A sterile upbringing gives no excercise to our immune system, weakening it. Sorry about that. Terry K |
#2
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holding tank hand pump
Terry Spragg wrote:
...It does work, and that logic stands in opposition, apparently, only to fear on the part of the operator who prefers to ignore head maintenance. Seems to me that preventative maintenance on the head & system is a lot easier than building a whole tank & piping system from scratch, so that you can pump it up with air pressure, which you wouldn't need to do with a normally functioning normal system. But pretzel logic appeals to many many people. Glad you're enjoying it. ....We evolved in natural healthy 'filth' unimaginable to modern youth, and it did not stop us from prospering, perhaps too much. A sterile upbringing gives no excercise to our immune system, weakening it. So no you compound pretzel logic with buffoonish disregard for facts? I guess your immune system got "exercised" enough to be resistant to typhoid, cholera, polio, amoebic dysentery, etc etc. Funny, a couple hundred thousand years of human evolution failed to do that, I wonder how you succeeded? Disdain for squeamishness, yes... ignorance of basic microbiological facts... nyet. DSK |
#3
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holding tank hand pump
Terry Spragg wrote:
...It does work, and that logic stands in opposition, apparently, only to fear on the part of the operator who prefers to ignore head maintenance. Seems to me that preventative maintenance on the head & system is a lot easier than building a whole tank & piping system from scratch, so that you can pump it up with air pressure, which you wouldn't need to do with a normally functioning normal system. But pretzel logic appeals to many many people. Glad you're enjoying it. ....We evolved in natural healthy 'filth' unimaginable to modern youth, and it did not stop us from prospering, perhaps too much. A sterile upbringing gives no excercise to our immune system, weakening it. So no you compound pretzel logic with buffoonish disregard for facts? I guess your immune system got "exercised" enough to be resistant to typhoid, cholera, polio, amoebic dysentery, etc etc. Funny, a couple hundred thousand years of human evolution failed to do that, I wonder how you succeeded? Disdain for squeamishness, yes... ignorance of basic microbiological facts... nyet. DSK |
#4
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holding tank hand pump
DSK wrote:
Terry Spragg wrote: I can use a bicycle pump or similar to evacuate my holding tank offshore. I close both air vents, open the sea valve, and pump up the holding tank with air. This is a really bad idea. The question is not *if* the tank will blow up, but when. Woudn't that depend on system parameters and design? If one pound pressure won't do 'it' in my system, then there is something else to look at. The highest standard for marine tanks (including fuel BTW) and associated fittings is .5 psi overpressure. Most are not built to withstand even that much. Who's fault or design is that? If you really have been doing this Terry, you've been very lucky (and so have your neighbors). Fresh Breezes- Doug King Amen to that;-) I would likely not try to shoot PWC's with poo from the deck cannon, but the thought is so entertaining, I just might be tempted after dinner and drinks on the hook. Keep clear, PWC fools! You ought to spread the word that this is a viable system, maybe it will keep them away if a story, even a bogus story should be told... I built the tank out of 1/4" thick polyester and glass, except for the top, which is more like 3/16" thick, with an epoxy lining. I do not do this deck cannon blow regularly, but did do it to see if it would work when it was new and clean. It works. After it has aged a few more years, when the joker is a little older, I intend to clean it out as well as can be done, and then I will see where the weak link is, just for fun, up to about 5 pounds just for the sake of curiosity. I am quit certain that the joker or a rubber bellows hose between the head and the Seacock will be the part that blows up eventually, even without 'dive pressure' testing. The tank itself is not rated, and has not been tested to destruction, so I can't say, yet. It can take about a 10 foot head of pressure. I do check for leaks under moderate pressure before launch, and would expect to detect seepage before total failure in the joker, which I will not change until I must. Moderate pressure is about 10 pounds force on the head pump handle, which, by thumb, equates with about 2 pounds system pressure. It would be possible for a normal physique to apply perhaps 50 pounds force, or 10 lbs system overpressure. That would be very scary, but I doubt anybody could be so stupid as to actually lean that hard on the handle, as someone suggests must have been done, since he said it blew up. When I got the boat, the joker was the wrong one, and leaked. That is where I started. I wonder how many others are co-existing with a dodgy setup, improperly maintained? Usually I 'blow tanks' via the head seacock which is only about an inch below the waterline, so the pressure required in too low to register on any gague that I have. The top quarter of the holding tank runs out without assistance, anyway, on starboard tack It does work, and that logic stands in opposition, apparently, only to fear on the part of the operator who prefers to ignore head maintenance. After some of the messes I have cleaned up, a little poo from folks I know is of small consequence. They are all healthy, and I have developed a plumber's stomach, having raised a few kids from diapers to college, looking after an old relative or two, and having fixed a few heads, at sea and ashore, in the last 50 years. Not to wax too political, but so many people seem to be so unreasonably squeamish about such little things, akin to so many who seem so concerned with miniscule calculated risks in both physical safety and so called 'security.' There is, and can be, no perfect safety or security system. I cannot understand how such people ever get into thier boats for a sail, or thier cars to drive in traffic, or even get to sleep at night, given that it is so easy to blow up an entire city block with just a gallon or two of gasoline. It seems the stock market must respond too easily to minor rumours of 'terror' attacks on stock values, could this be a popular tool amongst market manipulators? Ask any farmer about animal husbandry, now there's a messy business. Do we all forget how recently is was that most folks a generation or two ago worked in shall we say, primitive conditions? How soon our expectations have risen, and how far. How quickly too, our modern conveniences have spoiled so many waterways for those who appreciate nature's way of sun, wind and water. Could it be that those who must have power boats are afraid to see close up and slowly the water over which they now travel so quickly? We evolved in natural healthy 'filth' unimaginable to modern youth, and it did not stop us from prospering, perhaps too much. A sterile upbringing gives no excercise to our immune system, weakening it. Sorry about that. Terry K |
#5
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holding tank hand pump
Terry Spragg wrote:
I can use a bicycle pump or similar to evacuate my holding tank offshore. I close both air vents, open the sea valve, and pump up the holding tank with air. This is a really bad idea. The question is not *if* the tank will blow up, but when. The highest standard for marine tanks (including fuel BTW) and associated fittings is .5 psi overpressure. Most are not built to withstand even that much. If you really have been doing this Terry, you've been very lucky (and so have your neighbors). Fresh Breezes- Doug King |
#6
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holding tank hand pump
Lew Hodgett wrote:
"TB" writes: I have a new Henderson Mk V pump, will it be suitable for plumbing into the system to empty the holding tank offshore, or will i need a specific type. Any recommendations? Henderson Mk V I can use a bicycle pump or similar to evacuate my holding tank offshore. I close both air vents, open the sea valve, and pump up the holding tank with air. I watch the joker valve for back leakage / wear indications, and now, use a 12 volt tire pump. When the pressure reaches about a pound, out goes the poo. If I did not open the sea cock, I could blow the contents out the deck pumpout fitting. I have an elbo I am tempted to screw into the deck fitting if ever any PWC gets too pesky, port side. Two elbows and a ball valve could provide a fully aimable poo cannon. Long range shots might be dangerous for the cabin crew / head attendant / leakage monitor. That capability suggests a thru hull for sewage may not be required. I have pressure tested the system when new with water. I can nervously saw I would trust it to about 10 yards with short wait times at the ready. Pirates? Bring 'em on! This system also obviates no need for a working shoreside pump, and requires only a holding tank on the gas dock, which could remove many objections by marina operators about pumpout maintenance costs. It could also make boats cheaper. Of course, a flexible vacuum hose to a parking spot for a city services sewer sucker truck up on the bank would still be needed. Oh, and a level indicating clear overflow tube / vent outside the dock holding tank, wired to a pumpout service call buzzer / alarm. I would not normally employ my system to blow sewage up more than about 3 feet, realistically. Such a system would contribute greatly toward lowering shoreside pumpout equipment costs, as a suction rated pumpout hose on the dock is no longer needed. Mind, a leaky sewer hose on deck is quite noticable and might be repaired more quickly than a plain cantankerous vacuum leaking one. Sell the pump. Terry K |
#7
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holding tank hand pump
"TB" writes: I have a new Henderson Mk V pump, will it be suitable for plumbing into the system to empty the holding tank offshore, or will i need a specific type. Any recommendations? Henderson Mk V -- Lew S/A: Challenge, The Bullet Proof Boat, (Under Construction in the Southland) Visit: http://home.earthlink.net/~lewhodgett for Pictures |
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