Hi Peggy, This is the culmination of 6 months of planning, measuring, and remeasuring and I just wanted to check out a few decisions I have made. First, I am replacing one of those aluminum holding tanks that Hunter thought was such a great idea back in the day. They even gave me the aluminum tank manufacturer for a replacement tank... Like I am going to do that... I have found a perfect fit from Ronco (20 B 349) and Ocean Link (OLT 304) to move the tank to under the aft bunk, right behind the head. It is larger (by 50%) and poly. Which brings me to my questions. 1. The hose run from the head to the tank will be a stright connection of 2". to do this I am getting the straight outlet for my Groco HF and connecting with flexable hose. With no run, I will not have a vented loop. Will this be OK? 2. We live and sail primarily in Rhode Island, a zero dicharge state... so I am planning on bypassing my y valve and manual overboard pump out and just run a hose to the deck pump out. What would the issues be for this 32 foot coastal cruiser? 3. To stabalize the 20 gallon poly tank I plan on filling the voids with structural foam. There just is not any room for any kind of wood supports and then I will replace the panel of the bunk that I must cut out to install the tank. It has been recomended that I get 1.5 lbs foam. Is this good advice? I have read every post on leaking Vision tanks back to 1999 on this site. It seems nobody has come up with an ideal replacement set up. I think this all will work... but... just want to make sure...We certainly want our sweet smelling boat back for a long time to come. Thanks Spencer
Replacing 1989 Hunter Vision 32 holding tank
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1. Did you really mean 2 INCHES...or 2 feet? No, you don't need a vented loop in the line from the head to the tank...IF you spec the inlet and vent fittings closest to the centerline of the boat, away from the hull. 2. It's illegal to dump a tank in any US waters, not just in RI. To dump a tank legally, you must be at least 3 miles out to sea from the nearest point on the whole US coast line. If you never get outside the "3 mile limit" you can't use a y-valve and pump anyway, so bypassing it--or just removing 'em altogether, as is required on many inland waters--is fine. However, I can't imagine that you wouldn't ever take a 32' boat at least 3 miles offshore...I'd keep 'em. But instead of a y-valve in the pumpout line, spec 2 discharge ports in the tank--one for the line to the deck pumpout, one to the pump and thru-hull. 3. There's no need to foam the voids around the tank...just make sure the tank can't slide around (they don't bounce), by either strapping it down or blocking the corners. Foaming it in can actually cause more problems that it solves.
1. Did you really mean 2 INCHES...or 2 feet? No, you don't need a vented loop in the line from the head to the tank...IF you spec the inlet and vent fittings closest to the centerline of the boat, away from the hull. 2. It's illegal to dump a tank in any US waters, not just in RI. To dump a tank legally, you must be at least 3 miles out to sea from the nearest point on the whole US coast line. If you never get outside the "3 mile limit" you can't use a y-valve and pump anyway, so bypassing it--or just removing 'em altogether, as is required on many inland waters--is fine. However, I can't imagine that you wouldn't ever take a 32' boat at least 3 miles offshore...I'd keep 'em. But instead of a y-valve in the pumpout line, spec 2 discharge ports in the tank--one for the line to the deck pumpout, one to the pump and thru-hull. 3. There's no need to foam the voids around the tank...just make sure the tank can't slide around (they don't bounce), by either strapping it down or blocking the corners. Foaming it in can actually cause more problems that it solves.
Thanks, Yes it is 2 inches
Thanks Peggy, The connection from the head to the tank will be 2 inches, and will be 12 inches from the centerline. Thanks, Spencer
Thanks Peggy, The connection from the head to the tank will be 2 inches, and will be 12 inches from the centerline. Thanks, Spencer
I'm really curious...
Unless the tank will sit below the toilet (hard to do on a sailboat, but not impossible), how can the discharge hose from the toilet be only 2" long and still connect to the tank at the top? 'Cuz you can't put the inlet on the tank any lower...if you do, when the contents rise to the inlet, they'll flow back to the toilet. The inlet fitting has to be at--or better yet, on--the top of the tank...and I don't see how that's possible with only a 2" discharge hose.
Unless the tank will sit below the toilet (hard to do on a sailboat, but not impossible), how can the discharge hose from the toilet be only 2" long and still connect to the tank at the top? 'Cuz you can't put the inlet on the tank any lower...if you do, when the contents rise to the inlet, they'll flow back to the toilet. The inlet fitting has to be at--or better yet, on--the top of the tank...and I don't see how that's possible with only a 2" discharge hose.
Peggy, your comments inspire a question
Why have so many holding tanks been plumbed on the sides? From the top of the output hole where suction is lost to the bottom of the tank is 2-3 inches and from the bottom of the intake hole to the top of the tank is about the same so the tank has lost 4-6 inches of volume. If the tank is 24 inches tall, it has lost 16-25% of its capability? I know in this business if ya gotta do it... but, I liked your suggestion for on top fittings. Fitting a suction tube to the outlet fitting so that it is close to the bottom of the tank shouldn't be that hard. How far off the bottom should the tube be? Do the tanks when full, squat (bulge)thereby lowering the top and possibly drawing a tube too close to the bottom? Just curious....thanks.
Why have so many holding tanks been plumbed on the sides? From the top of the output hole where suction is lost to the bottom of the tank is 2-3 inches and from the bottom of the intake hole to the top of the tank is about the same so the tank has lost 4-6 inches of volume. If the tank is 24 inches tall, it has lost 16-25% of its capability? I know in this business if ya gotta do it... but, I liked your suggestion for on top fittings. Fitting a suction tube to the outlet fitting so that it is close to the bottom of the tank shouldn't be that hard. How far off the bottom should the tube be? Do the tanks when full, squat (bulge)thereby lowering the top and possibly drawing a tube too close to the bottom? Just curious....thanks.
It's really a trade-off...
Unless the fittings on a vertical surface have been installed much further from the top and bottom than they need to be, you should only lose about 4" total of usable capacity. There are 231 cu. in in a gallon...so you don't lose as much as you think. Fittings on the top of a tank require at least 5" of space above the tank...so unless you have room to go with a longer and wider tank, do you go with a tank that's 5" shorter, or lose about 4" of tank capacity? The real advantages to putting all the fittings on the top are: 1. no standing waste in the lines, reducing odor permeation in hoses...2. No spill when the hoses have to be replaced or removed to service a y-valve, pump or seacock.
Unless the fittings on a vertical surface have been installed much further from the top and bottom than they need to be, you should only lose about 4" total of usable capacity. There are 231 cu. in in a gallon...so you don't lose as much as you think. Fittings on the top of a tank require at least 5" of space above the tank...so unless you have room to go with a longer and wider tank, do you go with a tank that's 5" shorter, or lose about 4" of tank capacity? The real advantages to putting all the fittings on the top are: 1. no standing waste in the lines, reducing odor permeation in hoses...2. No spill when the hoses have to be replaced or removed to service a y-valve, pump or seacock.
It is into the side at the top
Yes Peggy, The 2 inch connection to the inlet is to the top of the tank, and will probably be down from the head outlet to the tank inlet. The Head sits on a platform with a bulkhead right behind it. I will dril a hole through the fiberglass that supports the bulkhead and the male barbed fitting will protrude through the hole about a half inch below center of the head outlet. I expect 1.5 - 2 inches of gap between the two fittings. Hose will actually be 5 - 6 inches. I will probably need to put the hose on the toilet outlet, then the tank and then mount the head outlet to the toilet. It is tight, that is why I have created a template of the tank and measured it four times, and probably will again. I will run the vent off the aft end of the tank top center corner to the stern of the boat (2 feet). Outlet I will use a dip tube and run it to the standard pump out (6 feet?) Spencer
Yes Peggy, The 2 inch connection to the inlet is to the top of the tank, and will probably be down from the head outlet to the tank inlet. The Head sits on a platform with a bulkhead right behind it. I will dril a hole through the fiberglass that supports the bulkhead and the male barbed fitting will protrude through the hole about a half inch below center of the head outlet. I expect 1.5 - 2 inches of gap between the two fittings. Hose will actually be 5 - 6 inches. I will probably need to put the hose on the toilet outlet, then the tank and then mount the head outlet to the toilet. It is tight, that is why I have created a template of the tank and measured it four times, and probably will again. I will run the vent off the aft end of the tank top center corner to the stern of the boat (2 feet). Outlet I will use a dip tube and run it to the standard pump out (6 feet?) Spencer
Well.. Now you've got me worried
So... I guess I need to have more holding back the floods of waste than the joker valve? Attached is the schematic of the tank I wish to use. As I said I plan on having the inlet in the side that is 19" long about 6 " in from the 12" deep corner. From your comments, I need to pay attention to the heeling angles. So I am thinking, I do need some sort of loop to be above this potential high waste line. Not the elegent direct connection that I was planning. Other than buying your book, how can I help support your service. I can't find Peal. Thanks for your service. Spencer
So... I guess I need to have more holding back the floods of waste than the joker valve? Attached is the schematic of the tank I wish to use. As I said I plan on having the inlet in the side that is 19" long about 6 " in from the 12" deep corner. From your comments, I need to pay attention to the heeling angles. So I am thinking, I do need some sort of loop to be above this potential high waste line. Not the elegent direct connection that I was planning. Other than buying your book, how can I help support your service. I can't find Peal. Thanks for your service. Spencer
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