Hi all, just dropping a note about the aft holding tank on my 1986 Hunter 40..... i have repaired it, and added a "tank full" sensor it was a tough job but in the end worth it! Details: 1) the tank is integral to the hull liner 2) there is a glassed on cover - mine was mostly resin, and the seam popped from overpressure when the vent line became clogged (previous owner!) 3) had to remove the port setee to get at the section of sole covering the tank - the small door at the foot of the nav table (where the hoses are visable) is actually the back corner of the tank 4) after sole is lifted the tank is accessable for repair (i ground down and reglassed the seam) 5) a low profile sensor is required because there is little clearance between the sole and cover of the tank (if you get this far you can see where Hunter builders had to plane 1/4-1/2 inch off the underside of the sole plywood) 6) wires from the sensor are easily ran up the wall where that afore mentioned access door is located It was lots of work but worth it in the end to know when the tank was getting full - I would say that about 125 pumps of the head gets it almost half full ( hard to tell exactly because the tank shape has a slope like the hull) Anyways, no more strange smells and a much happier couple my wife and me are now! Jon p.s. I have pictures of the whole process if there is any interest
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Peggie Hall/Head Mistress
Why just a "tank full" sensor?
In my experience, when all you have is a "full" light, it's always guaranteed to come on with the first flush after you're securely tied up as the middle boat in a 6 boat raft. For very little more $$, you could have put an AcuGage "mini" on the tank that reads 1/4, 1/2, 3/4, full. Sender goes on the outside of the tank, so it can never clog or corrode. And since it's calibrated on the tank, the sloped side makes very little difference. It's not too late...you said running the wiring was easy. You can use the two existing wires and only have to run the third. I don't see it in he online store here, but they can get it. Or, you can go first class and put ALL your tanks on a single system. Check 'em out on their website...link below. This is the system that Hunter is now putting on all their boats.
In my experience, when all you have is a "full" light, it's always guaranteed to come on with the first flush after you're securely tied up as the middle boat in a 6 boat raft. For very little more $$, you could have put an AcuGage "mini" on the tank that reads 1/4, 1/2, 3/4, full. Sender goes on the outside of the tank, so it can never clog or corrode. And since it's calibrated on the tank, the sloped side makes very little difference. It's not too late...you said running the wiring was easy. You can use the two existing wires and only have to run the third. I don't see it in he online store here, but they can get it. Or, you can go first class and put ALL your tanks on a single system. Check 'em out on their website...link below. This is the system that Hunter is now putting on all their boats.
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Jon
Stringer obstruction
My first idea was to get the nicest fanciest device I could - since the hardest part was getting to the tank in the first place! The problem is that there is no access to the side of the tank, as it is the space between the molded stringers in the hull liner. There exists about an 8" molded beam on each side of the space that makes up the tank. Any "passive" monitor systems that I looked at wouldn't have worked - the only way in was through the cover(top). The only low profile sensor (that would fit within the 1/2" clearance was a simple float switch. This switch trips with about 3-4" of "head" room in the tank (fell on that pun!) - so I figure the light comes on at a little over 1/2 tank full. It's a nice reminder to get over to the pumpout. So far it has worked well - most important it gives a feel for how many days "head use" you get between pumpouts. Jon
My first idea was to get the nicest fanciest device I could - since the hardest part was getting to the tank in the first place! The problem is that there is no access to the side of the tank, as it is the space between the molded stringers in the hull liner. There exists about an 8" molded beam on each side of the space that makes up the tank. Any "passive" monitor systems that I looked at wouldn't have worked - the only way in was through the cover(top). The only low profile sensor (that would fit within the 1/2" clearance was a simple float switch. This switch trips with about 3-4" of "head" room in the tank (fell on that pun!) - so I figure the light comes on at a little over 1/2 tank full. It's a nice reminder to get over to the pumpout. So far it has worked well - most important it gives a feel for how many days "head use" you get between pumpouts. Jon
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Peggie Hall/Head Mistress
Ohhh, I hate to break this to you, but...
but just about everyone who's ever had a float-switch sender in a holding tank has problems with 'em...the reason why Hunter (and a lot of other boatbuilders too) have switched to the capacitor type of sending unit that never comes in contact with tank contents. Waste contains animal fats which clog up the float. Since you no longer have access to the tank (what about the door under the chart table?) you'll need to do all you can to prevent it, 'cuz you can't take it out to clean it (which isn't any fun anyway)...about once a month, flush out the tank with water, then add a healthy dose of low-suds detergent (Wisk is good)...and go sailing. Tack a lot, so the soapy water can really slosh around in the tank...then drain and rinse the tank and add your holding tank treatment before using the toilet again. Don't let it clog up...'cuz once it does, it can be cleaned, but if you think prevention is a major pain, cure is harder. Sure do wish you'd asked a few more questions before you did all the work...<sigh>
but just about everyone who's ever had a float-switch sender in a holding tank has problems with 'em...the reason why Hunter (and a lot of other boatbuilders too) have switched to the capacitor type of sending unit that never comes in contact with tank contents. Waste contains animal fats which clog up the float. Since you no longer have access to the tank (what about the door under the chart table?) you'll need to do all you can to prevent it, 'cuz you can't take it out to clean it (which isn't any fun anyway)...about once a month, flush out the tank with water, then add a healthy dose of low-suds detergent (Wisk is good)...and go sailing. Tack a lot, so the soapy water can really slosh around in the tank...then drain and rinse the tank and add your holding tank treatment before using the toilet again. Don't let it clog up...'cuz once it does, it can be cleaned, but if you think prevention is a major pain, cure is harder. Sure do wish you'd asked a few more questions before you did all the work...<sigh>
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Jon
Again...
As I stated before; unless I cut through a STRUCTURAL beam there was no access to the side of the tank. I deemed this approach to be less than prudent - As for the access through the small door, this is the side of the tank furthest up the hull - thus the depth here is not more than an inch or so - this also provides only access to the top, as there is no side to the tank at this point. The Hunter builders I'm sure understood the limitations of this design, and have rightly addressed the problem on newer boats. I do appreciate the advances of modern technology, however the cost/benefit analysis for this project left me with few choices. This boat has made it 16 years without a tank sensor, so I figured I couldn't make things any worse. Each time I pump out the tank, I refill it to provide a "clean" rinse; along with the usual tank additives I will employ your wisk tip and hope for the best. So far I have had no problems. The point to this submission was to converse with individuals contemplating what to do about their leaking aft head on their Hunter 40. I have documentd the process of getting to the tank (most of the work), and what things look like once you get there. I thought that this would help others muster the courage to venture forth when posed with a similar challenge. For those interested, I have pictures of the process and would be happy to share them. Thanks, Jon
As I stated before; unless I cut through a STRUCTURAL beam there was no access to the side of the tank. I deemed this approach to be less than prudent - As for the access through the small door, this is the side of the tank furthest up the hull - thus the depth here is not more than an inch or so - this also provides only access to the top, as there is no side to the tank at this point. The Hunter builders I'm sure understood the limitations of this design, and have rightly addressed the problem on newer boats. I do appreciate the advances of modern technology, however the cost/benefit analysis for this project left me with few choices. This boat has made it 16 years without a tank sensor, so I figured I couldn't make things any worse. Each time I pump out the tank, I refill it to provide a "clean" rinse; along with the usual tank additives I will employ your wisk tip and hope for the best. So far I have had no problems. The point to this submission was to converse with individuals contemplating what to do about their leaking aft head on their Hunter 40. I have documentd the process of getting to the tank (most of the work), and what things look like once you get there. I thought that this would help others muster the courage to venture forth when posed with a similar challenge. For those interested, I have pictures of the process and would be happy to share them. Thanks, Jon
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tom lueck
send me the pic's
i would like to have the pictures for future referance... i also own a 1986 hunter 40.. thanks tom lueck stknbmxer@aol.com
i would like to have the pictures for future referance... i also own a 1986 hunter 40.. thanks tom lueck stknbmxer@aol.com
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Kevin Whalen
Jon's Right
Jon I had to repair the same integral tank on my 85 Hunter 40. One of the seams had broken loose from the stringer. You are correct there is no way to put a tank gauge on the exterior of the integral tank. It is surrounded by stringers and the exterior hull. I actully put so much epoxy on the lid that I ground the void on the bottom floor board even deeper. Hopefully it will hold another 17 years. Kevin
Jon I had to repair the same integral tank on my 85 Hunter 40. One of the seams had broken loose from the stringer. You are correct there is no way to put a tank gauge on the exterior of the integral tank. It is surrounded by stringers and the exterior hull. I actully put so much epoxy on the lid that I ground the void on the bottom floor board even deeper. Hopefully it will hold another 17 years. Kevin
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