I have just bought a 1990 Hunter 35.5 and know that I need to replace the aluminum holding tank. I planned to replace it anyway -- clearly a problem point for this model -- but now learn from the previous owner that he has seen leakage at a seam. There are several excellent posts here back to 1999 and a great set of photos on how to do this. My questions are, to any who can answer: -- Which replacement tank did you use? Did anyone try a tank that is curved on the port side so that a bigger tank will fit in the space? -- Did you run into any specific problems cutting an access hole in the aft bulkhead? -- How did you secure the tank in place? I've read about canvas straps, wood stringers and other creative solutions and am looking for the approach that works and is minimally labor-intensive. -- Does anyone disagree with this wisdom I've gleened from the posts - don't try to remove the hoses, cut them, plug them and replace them. -- Any other 'wish I had done it this way' suggestions?
Replacing the holding tank
- Thread starter Dipboye
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Did mine on a 33.5
I did mine in a 1993 33.5.Called Hunter and got the manufacturer of the aluminum tank.Called the company and gave them the year of the boat, they faxed me the blueprints with the measurements,they fit perfectly,then ordered the tank.Took one week, cost about $250 and was an exact replacement. Hope this helps.
I did mine in a 1993 33.5.Called Hunter and got the manufacturer of the aluminum tank.Called the company and gave them the year of the boat, they faxed me the blueprints with the measurements,they fit perfectly,then ordered the tank.Took one week, cost about $250 and was an exact replacement. Hope this helps.
Ronco Plastic - Replaced last year
I just did this last fall at the end of the season. I believe that the capacity of the original was 13 gals, I replaced it with the Ronco B171 which gives me 25 gal capacity. The raised angle went to the back, giving clearance over the fuel hoses. I built supports for the back to keep it from tilting backwards. All fittings went in the top, went with a 1" vent and the outlet is at the top with a dip tube. While I was in there, I pulled out all the hoses and replaced with new. The old tank was held in with stainless steel straps through holes in the floor of the platform that the tank sits on. I used ratcheting nylon webbing straps which I feel will hold it quite securely, and were very low in the labor department. Cutting the hole was not a problem, but the plywood that I cut out was not in great shape. Due to time constraints, it went back in as-is, but I'd like to pull it back out, get some new marine ply and laminate, and make a new cover. We'll see how much time I have this season. If you have any questions, feel free to contact me through the owners list. T J Furstenau ps - I may be at the boat this weekend and if so will try to snap a couple of pictures.
I just did this last fall at the end of the season. I believe that the capacity of the original was 13 gals, I replaced it with the Ronco B171 which gives me 25 gal capacity. The raised angle went to the back, giving clearance over the fuel hoses. I built supports for the back to keep it from tilting backwards. All fittings went in the top, went with a 1" vent and the outlet is at the top with a dip tube. While I was in there, I pulled out all the hoses and replaced with new. The old tank was held in with stainless steel straps through holes in the floor of the platform that the tank sits on. I used ratcheting nylon webbing straps which I feel will hold it quite securely, and were very low in the labor department. Cutting the hole was not a problem, but the plywood that I cut out was not in great shape. Due to time constraints, it went back in as-is, but I'd like to pull it back out, get some new marine ply and laminate, and make a new cover. We'll see how much time I have this season. If you have any questions, feel free to contact me through the owners list. T J Furstenau ps - I may be at the boat this weekend and if so will try to snap a couple of pictures.
Thanks for the help
Thanks for the reply on the holding tank! Can I ask a couple of questions? "I replaced it with the Ronco B171 which gives me 25 gal capacity. The raised angle went to the back, giving clearance over the fuel hoses." I like this better than a previous post that described building a 1" high platform to clear the hoses. "All fittings went in the top, went with a 1" vent and the outlet is at the top with a dip tube." I'll show my ignorance - what is a dip tube? The 1" vent is the hose to the starboard side vent under the helmsmans seat? Was there much difficulty connecting the hoses to the top outlet once the tank was in place? Were the fittings the standard for the Ronco model you used or did you have to change things? "I used ratcheting nylon webbing straps which I feel will hold it quite securely, and were very low in the labor department. " I haven't cut the hole yet so haven't seen this. Is there a straightforward way to anchor the straps down without putting a screw through the hull? Thanks again for saving me hours.
Thanks for the reply on the holding tank! Can I ask a couple of questions? "I replaced it with the Ronco B171 which gives me 25 gal capacity. The raised angle went to the back, giving clearance over the fuel hoses." I like this better than a previous post that described building a 1" high platform to clear the hoses. "All fittings went in the top, went with a 1" vent and the outlet is at the top with a dip tube." I'll show my ignorance - what is a dip tube? The 1" vent is the hose to the starboard side vent under the helmsmans seat? Was there much difficulty connecting the hoses to the top outlet once the tank was in place? Were the fittings the standard for the Ronco model you used or did you have to change things? "I used ratcheting nylon webbing straps which I feel will hold it quite securely, and were very low in the labor department. " I haven't cut the hole yet so haven't seen this. Is there a straightforward way to anchor the straps down without putting a screw through the hull? Thanks again for saving me hours.
TJ ?
Could you also address what it took to change out the hoses. Did they come out fairly easily or was it a major hassle? I've never read where anyone said to cut and plug the hoses, you wouldn't have room to run new ones if you did that. Your advice is appreciated.
Could you also address what it took to change out the hoses. Did they come out fairly easily or was it a major hassle? I've never read where anyone said to cut and plug the hoses, you wouldn't have room to run new ones if you did that. Your advice is appreciated.
Answers to your questions...
Starting with Ronco tanks...Ronco Plastics makes top quality thickwalled plastic tanks for a very reasonable price and have more than 400 shapes and sizes, including over 100 non-rectangular..and unlike "off the shelf" tanks, they don't have any pre-set fittings...they install the fittings in the sizes and locations specified by the customer when they make the tank...so you can put 'em where you want 'em. Their catalog is on the web here http://www.ronco-plastics.com A diptube is a tube inside the tank from a discharge fitting on the top of the tank...if you want all your fittings on top--which is a VERY good idea, but does require at least 5" clearance above the top of the tank--just specify that you want one when you order the tank. As for how to anchor the straps without putting screw through the hull, use screws short enough not to go all the way through.
I'm actually serious...there will be so little strain on the straps that you only need to anchor 'em, so a screw that only goes 1/4-1/2" into the hull is all you need...and it won't hurt the hull. You'd be amazed at how many screws there are in it already. You might also want to check out the link below before you start this project. Several chapters are devoted to choosing and installing a tank and and replacing hoses, and include tips that make the job considerably easier.
Starting with Ronco tanks...Ronco Plastics makes top quality thickwalled plastic tanks for a very reasonable price and have more than 400 shapes and sizes, including over 100 non-rectangular..and unlike "off the shelf" tanks, they don't have any pre-set fittings...they install the fittings in the sizes and locations specified by the customer when they make the tank...so you can put 'em where you want 'em. Their catalog is on the web here http://www.ronco-plastics.com A diptube is a tube inside the tank from a discharge fitting on the top of the tank...if you want all your fittings on top--which is a VERY good idea, but does require at least 5" clearance above the top of the tank--just specify that you want one when you order the tank. As for how to anchor the straps without putting screw through the hull, use screws short enough not to go all the way through.
I'm actually serious...there will be so little strain on the straps that you only need to anchor 'em, so a screw that only goes 1/4-1/2" into the hull is all you need...and it won't hurt the hull. You'd be amazed at how many screws there are in it already. You might also want to check out the link below before you start this project. Several chapters are devoted to choosing and installing a tank and and replacing hoses, and include tips that make the job considerably easier.Peggie's Right of Course
Her explanation of the dip tube is right on. The discharge fitting is at the top, and the fitting has a tube, cut slanted at the bottom, that reaches to the bottom of the tank to allow pump out. Now, TECHNICALLY, the tank when pumped out leaves something at the bottom, but with a couple of rinses should leave very little offensive material. And even if it leaves something, it's at the bottom of the tank and not in the hose. That was one of many pieces of "Peggy wisdom" that I took advantage of. Another was replacing the small vent line to the starboard capped vent thru hull with a 1" vent line to a standard through hull. I had to drill out the old hole and put a new backer in. It sits far enough above the waterline, even when heeled, that there is no seacock. As far as the 5" above the tank for all fittings, I think I was able to squeeze it in with less, but not much less, and SQUEEZE is a key word. A key to fittings and hoses that I learned the hard way - I got the hose (AVS96) at http://www.aussieglobe.com which I understand is the old Sealand hose and very good. You need their PVC fittings to be able to attach the hose, and I found that using a hair dryer and a little lubricant was necessary to get the hose on the fitting. The mistake I made was putting the fittings on the elbows into the tank and THEN trying to get the hose on. Put the PVC Sealand fittings on the end of the hose where you've got room to work, and THEN lead them to the tank and glue them up to your PVC elbows. Hopefully that makes sense. As far as running the hoses, tank to head wasn't too bad, with decent access under the rear cabin berth. The boat had a macerator plumbed in previously, but I had no use for it on the Great Lakes, so I left it out of the equation. The pumpout and vent hoses were a little bit of a challenge, and probably would have been easier with a little assistance, but I was solo the weekend of the install. As far as fastening the tank in, there is a molded in platform that the tank sits on. It had four holes, approximately 1" in diameter drilled in it, forming a square. The old tank had two steel straps that went in one hole, out the next, and then around the tank. I used the same holes, and same principle, but rather than stainless straps (as I don't have the equipment to secure them) I used two ratching tie-downs. One thing that I did have to fashion was a support for the back of the tank that matched the angle in the tank to support it, while clearing the fuel hoses. Was really fairly simple, and not one of my prettier attempts at carpentry, but no one would ever see it. Some marine ply with a few coats of epoxy to seal. As I said, I'll try to get some pictures for you this weekend, or shoot me an email and I'd be happy to respond with further contact info if you want more help. T J
Her explanation of the dip tube is right on. The discharge fitting is at the top, and the fitting has a tube, cut slanted at the bottom, that reaches to the bottom of the tank to allow pump out. Now, TECHNICALLY, the tank when pumped out leaves something at the bottom, but with a couple of rinses should leave very little offensive material. And even if it leaves something, it's at the bottom of the tank and not in the hose. That was one of many pieces of "Peggy wisdom" that I took advantage of. Another was replacing the small vent line to the starboard capped vent thru hull with a 1" vent line to a standard through hull. I had to drill out the old hole and put a new backer in. It sits far enough above the waterline, even when heeled, that there is no seacock. As far as the 5" above the tank for all fittings, I think I was able to squeeze it in with less, but not much less, and SQUEEZE is a key word. A key to fittings and hoses that I learned the hard way - I got the hose (AVS96) at http://www.aussieglobe.com which I understand is the old Sealand hose and very good. You need their PVC fittings to be able to attach the hose, and I found that using a hair dryer and a little lubricant was necessary to get the hose on the fitting. The mistake I made was putting the fittings on the elbows into the tank and THEN trying to get the hose on. Put the PVC Sealand fittings on the end of the hose where you've got room to work, and THEN lead them to the tank and glue them up to your PVC elbows. Hopefully that makes sense. As far as running the hoses, tank to head wasn't too bad, with decent access under the rear cabin berth. The boat had a macerator plumbed in previously, but I had no use for it on the Great Lakes, so I left it out of the equation. The pumpout and vent hoses were a little bit of a challenge, and probably would have been easier with a little assistance, but I was solo the weekend of the install. As far as fastening the tank in, there is a molded in platform that the tank sits on. It had four holes, approximately 1" in diameter drilled in it, forming a square. The old tank had two steel straps that went in one hole, out the next, and then around the tank. I used the same holes, and same principle, but rather than stainless straps (as I don't have the equipment to secure them) I used two ratching tie-downs. One thing that I did have to fashion was a support for the back of the tank that matched the angle in the tank to support it, while clearing the fuel hoses. Was really fairly simple, and not one of my prettier attempts at carpentry, but no one would ever see it. Some marine ply with a few coats of epoxy to seal. As I said, I'll try to get some pictures for you this weekend, or shoot me an email and I'd be happy to respond with further contact info if you want more help. T J
Re AVS96 sanitation hose
AVS96, made by Australian Global Services, is the same hose that SeaLand sold exclusively in the US as their private label brand name "OdorSafe," and has been proven in independent testing to be at least 16x more resistant to odor permeation than any other hose in the world. Not long after Dometic--an Italian mfr who specializes primarily in RV equipment--acquired SeaLand from N.A. Taylor, SeaLand switched to an Italian hose mfr. Is it as good as AVS96? All I know is that they now only claim that their new "OdorSafePlus" hose is 20% more resistant to odor permeation than most other hoses, are not promoting it at all...and have begun recommending hard PVC for some installations, and now offer fittings to connect hard pipe to hose. Meanwhile, AussieGlobe http://www.aussieglobe.com/avs96.htm is now selling their AVS96 hose direct here in the US--and for a LOT less than SeaLand charged for it, or for their new OdorsafePlus....only $5/ft, cut to any length vs. nearly $9/ft for SeaLand in min. 50' coils. I highly recommend it. The Aussies also make another product that's the slickest thing since sliced bread...they call it the Uniseal, and it makes moving or adding tank fittings a piece of cake. Check it out while you're on their site.
AVS96, made by Australian Global Services, is the same hose that SeaLand sold exclusively in the US as their private label brand name "OdorSafe," and has been proven in independent testing to be at least 16x more resistant to odor permeation than any other hose in the world. Not long after Dometic--an Italian mfr who specializes primarily in RV equipment--acquired SeaLand from N.A. Taylor, SeaLand switched to an Italian hose mfr. Is it as good as AVS96? All I know is that they now only claim that their new "OdorSafePlus" hose is 20% more resistant to odor permeation than most other hoses, are not promoting it at all...and have begun recommending hard PVC for some installations, and now offer fittings to connect hard pipe to hose. Meanwhile, AussieGlobe http://www.aussieglobe.com/avs96.htm is now selling their AVS96 hose direct here in the US--and for a LOT less than SeaLand charged for it, or for their new OdorsafePlus....only $5/ft, cut to any length vs. nearly $9/ft for SeaLand in min. 50' coils. I highly recommend it. The Aussies also make another product that's the slickest thing since sliced bread...they call it the Uniseal, and it makes moving or adding tank fittings a piece of cake. Check it out while you're on their site.
Go to the Photo Forum for 35.5
for descriptions on cutting the bulkhead and replacing the holding tank. All the info is there including dimensions on the cutout.
for descriptions on cutting the bulkhead and replacing the holding tank. All the info is there including dimensions on the cutout.
Uniseal
I'm trying to figure out why I need the uniseal product. The Ronco tanks will come with fittings built in, right? The hose will be clamped on so is anything else necessary? (a few hose clamps of course).
I'm trying to figure out why I need the uniseal product. The Ronco tanks will come with fittings built in, right? The hose will be clamped on so is anything else necessary? (a few hose clamps of course).
Aft Cabin Cutout Question
Jim Rushing, I just wanted to thank you for the excellent articles on cutting the aft cabin access and replacing the holding tank. I am getting ready to replace mine on a 1993. Just wanted to confirm that the 4.75 inches vertical demension on your aft cabin template is from the aft bed panels minus cushions. Any other wisdom offered before I start? Garth Pearce
Jim Rushing, I just wanted to thank you for the excellent articles on cutting the aft cabin access and replacing the holding tank. I am getting ready to replace mine on a 1993. Just wanted to confirm that the 4.75 inches vertical demension on your aft cabin template is from the aft bed panels minus cushions. Any other wisdom offered before I start? Garth Pearce
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