Integral water tank build

This is the place to post your ideas, thoughts, questions and comments as relates to general boatbuilding and reconstruction techniques and procedures (i.e. recoring, epoxy, fiberglass, wood, etc.)
Post Reply
HinduKush
Bottom Paint Application Technician
Posts: 18
Joined: Thu Jun 11, 2020 1:30 pm
Boat Name: Hindukush
Boat Type: Pearson Triton

Integral water tank build

Post by HinduKush »

Hello, I was thinking of putting the integral water tanks in the location of the head cutting down the paltform there. Making the tank about 16 inchs above the cabin sole and back to just under bottom locker opening to the hull in head area. In the hanging locker building another tank about 20 inch's high inside locker back to hull to have similar tank gallon capacity as the head tank. Relocating the head to vee berth seat under the hatch opening and running the head vent to the chain locker. One less deck penetration. Any thoughts on this idea? Thank you.
User avatar
atomvoyager
Moderator | Revitalizer of Classics
Posts: 421
Joined: Thu Jul 12, 2018 7:48 am
Boat Name: Atom
Boat Type: Pearson Triton
Contact:

Re: Integral water tank build

Post by atomvoyager »

I'm guessing you want to put the tanks there to avoid weight in the ends of the boat. If that's true, you might be introducing more problems doing that than you're solving. Even though you could keep monitoring and switching valves to draw them both down more or less equally, it's best to have them on the centerline when possible. Did you make a rough calculation of tank capacities, will these be the only tanks, and will they be enough to make it worthwhile? For liveaboard use I find tanks under about 20 gal are annoying to have to refill so often. Where is the head going if you use that space for a tank? Let's say you're dead set against a centerline big tank in the aft end of the v-berth as on Triton Osprey because you either don't want to fill in the walkway between the bunks or don't want to lose that spot for storage, you might still be better off by making a bilge tank in the head and forward main cabin area and an aft bilge tank in the useless space just forward of the rudder. Weight distribution is much better and better utilizes storage options. What's the downside of that for you?
HinduKush
Bottom Paint Application Technician
Posts: 18
Joined: Thu Jun 11, 2020 1:30 pm
Boat Name: Hindukush
Boat Type: Pearson Triton

Re: Integral water tank build

Post by HinduKush »

Hello,
I did take into consideration the water slosh between to opposing tanks and thought about a pipe under sole to help keep both tanks equal. That would not work at all unless it was dead calm and a check valve wouldn't work either. I was wondering about the weight being on the high side if the tanks where in the two lockers. I see where going with the weight distribution on the centerline and I agree. I also think your suggestion of a modified keel storage under vee berth encroaching under sole may be better idea? Making the bilge tank from under seat in vee berth back under sole but not whole length was that that your suggestion? Then an aft tank to make up for lost storage space. I like the feedback and I will think about how to make it be enough storage but not changing the layout of the existing boat.

I still wanted to put the shorty 15 inch high composting C-Head under the vee berth seat even if it encroches out 10 inches more in vee berth. I figured why look at it when you use it once a day. Plus run vent to chain locker. I wanted to put a folding bicycle in the head area or a Dometic 12 volt ice box on the water tank platform. Which I can still do in that area and have more storage with your plan.

Was also thinking of maybe putting folding bicycle under companionway or the cooler box on a slide out L shaped drawer. Using 500 pound rated SS slides that easily detached to gain access to batteries under steps. But was wondering about the cooling fan on the cooler box being enclosed in that location with limited circulation.

I never provisioned a boat so was thinking most of the keel storage would be for can food to keep the weight low. I will use the 4 day sprout container or something of the equivalent for micro greens.

Thank you for the helpful direction.
User avatar
atomvoyager
Moderator | Revitalizer of Classics
Posts: 421
Joined: Thu Jul 12, 2018 7:48 am
Boat Name: Atom
Boat Type: Pearson Triton
Contact:

Re: Integral water tank build

Post by atomvoyager »

The aft keel tank as on Osprey and Atom is the only ideal place that keeps weight low and on centerline and does not reduce storage options for other items. But it's only around 20 gal so you need a second tank. I was not considering a bilge thank that goes into the forward cabin. Might be doable but seems fraught with problems and the bilge space under the v-berth walk-thru is tiny anyway. The tank would be entirely in the forward bilge starting at the forward end of the head compartment just aft the step into the forward cabin and run aft as far as you can go while still leaving some space for bilge water in the aft main cabin between the two tanks. I have a video on my YT channel showing a center bilge tank going in an Alberg 30.

Another option is do like on Atom - aft bilge tank and second tank just forward of v-berth walk-thru area. If you don't like the weight just make it smaller, say 30 gal. The combined 50 gals is still more than your two side tanks. When you need more water you can carry some extra jugs. One reason I didn't mention equalizing the two side tanks with a valve is because it sounded like they were different heights.

If the toilet goes in forward cabin it will be awkward if you ever want to sleep there yourself or put crew there. If you're sure that's not the case, then it has the advantage that it could be easier to use at sea being on the centerline with a bunk close on each side to keep you from getting thrown around. But sailing is a small percentage of time when living aboard and maybe not worth the trade-offs when you can use a bucket and chuck it method when beating on port tack.

The smallest Dometic you can get away with will be best but it isn't practical to run it in the old engine locker unless it is open-topped because if it only has marginal ventilation the duty cycle and power draw will go way up fighting to keep cool. I like the concept though and maybe you can have the locker cover (is it doubling as top step as on Atom?) in two pieces and leave the aft piece off for ventilation when running the fridge. If you have a source for those stainless tracks let us know because I might use them somewhere myself. But running the fridge in your living area will add heat inside that may not be welcome. I like to have the option to move it between the v-berth when sailing and cockpit in port. Another issue is the old engine locker may not be tall enough for the tank, batteries, and Dometic. A carboard mockup will tell you. Or I can get a measurement of the Osprey locker height for you. I don't know if bike storage will be practical in the head but it can always go in the v-berth if you need to.
HinduKush
Bottom Paint Application Technician
Posts: 18
Joined: Thu Jun 11, 2020 1:30 pm
Boat Name: Hindukush
Boat Type: Pearson Triton

Re: Integral water tank build

Post by HinduKush »

Hello,

I really liked the Iroko wood floor with the black Polysulfied caulk. I was thinking I don't think I could do as nice a job of it as you did. I did watch those videos in the past and glad you suggested I review them again. I watched the A30 and the Allied 30 interior and intragal tank installations. I am thinking your right and a cabin sole tank would be a better utilized for my carpentry skills. The smooth clean look of the Allied sole was attractive and hardy in the long run.

As for the head location under the vee berth seat. I wanted to vent it to the chain locker one less deck hole. I had a multi purpose roll for that area as well. First was the head, second a dressing seat and third was thinking hooking up a curtain (wife) and using it as a seated shower with a drain to the bilge from the chain locker drain. Into that compartment. I wanted to make a 3 gallon solar shower of black pvc to sit on deck by the Ocean 60 Lewmar hatch and the spray hose into the cabin. Luxury. :). I.E. to be used in favorable conditions. So make her happy and an airy location under the hatch with the option to also provide standing headroom for us guys if we wanted to indulge. Condition and location permitting.

The bicycle location I was thinking the former head area. I want use a bike to explore and I have bicycle toured for years in different parts of the world. I don't like to be at the mercy of public transportation. I wanted options to do some semi extended multiday trips or farther around a port. Also reprovesioning may be easier? You can take the bike with you in the store. I like a full size bike and have a full size touring bike but it's not practical for a 28 foot boat.

So I choose the Brompton Folding bike as a suitable candidate for my purposes. The bike folds into thirds so a compact 23x22x10 so the head locker would actually accommodate two Bromptons. Still be able to utliize the lockers there. The Bromptons when they are folded rest on their own rear racks which also sport casters to roll them around in airports, mass transit, grocery store etc. Super clever design. They are still hand made in the UK. Excellent quality but they tend to be pricey new but the upside is a Brompton built 30 plus ago is the same as today. So the parts are available very easily even if you find an older model on sale. That British mentality if it works why change it, which I like. Plus it is a cool company.

So I now agree with your thinking a cabin sole tank would be most practical. It also makes me feel less pensive about having the cabin sole look like an Amish craftsman created it.

How many gallons do you think it would yield? Do you think I would loose essential storage space? I probably would not need aft bilge tank? Maybe a bouancy chamber in that location?

The dometic Cool freeze sizes I was looking at draw the same amps .74 on the specs and the CFX28, 35 and I think the 41 where the same maybe 10th of an amp difference. All modles size specs where I think manageable I was leaning torwards the CFX35?? No hard numbers on the dimensions in the companionway.
So the slide out would have a removable counter top like your Osprey had. The front door with the step attached would either come off or stay attached to the bottom board and have a 1 inch by 4" wood strip under the step to use as a pull. Then the Dometic Cool freeze would sit on the flat board. The board you used to cover the bilge and pumps. Yes the top loading portable Dometic Cool freeze similar to Jason's Alberg 30 Lora had in the vee berth. Your idea of keeping the back open I like and it may disperse the heat better? Or maybe have the front door removable in the mid day. I was thinking maybe semi open to nav station and galley box?

Dometics are very pricey. Ridiculously so. I would want to make sure I wouldn't blow it up.
User avatar
atomvoyager
Moderator | Revitalizer of Classics
Posts: 421
Joined: Thu Jul 12, 2018 7:48 am
Boat Name: Atom
Boat Type: Pearson Triton
Contact:

Re: Integral water tank build

Post by atomvoyager »

A bilge tank of 72" length would give you about 35-38 gals. I would not bother with smaller than 66". The aft tank would be welcome for sure and as I said it is the only location that does not reduce storage. Replacing it with a buoyancy chamber seems tragic, but doable if you had a good reason. No matter where you place the other tank it reduces storage so not much point of worrying about that compared to the more important considerations of pros and cons of one location versus another. My forward bilge holds a spare disassembled fortress anchor, a bit of chain and two rodes that could be moved to a cockpit locker. Canned food in the bilge requires sealed tuperware boxes to prevent chafe and rust which is awkward to use so actual useable storage there is less than you think. Brian on the Seawind had to repair his tank top from rot after a couple years due to a pinhole leak in the epoxy sealed wood around the top access plate so make sure you use marine ply and seal it very well on all edges or if you can afford it, use coosa or other less dense synthetic coring like core-cell with fiberglass on each side. I also had one of my tank tops go rotten on one boat and had to redo it so I try to be extra cautious on sealing them now.

Venting the head to the chain locker can work using an extraction fan somewhere and I guess your idea was to use the original dorade? But that needs closing at sea so maybe not ideal. Of course you need a gasket on the chain locker door but that's wanted regardless. Bike storage in the head may block the medicine cabinet unless the door opening is raised or maybe you could tear it out and add a canvas pocket wall storage type system somewhere to make up for it. The inside shower while seated on the toilet could work but only useful for cold windy weather. Otherwise, sitting in the cockpit footwell, using privacy/wind shield side curtains attached to bimini or awning as needed is preferable. Have the wife try a garden sprayer shower before building a gravity feed box on deck. It saves more water too. Or why not use a portable, less bulky solar shower bag lashed on deck with an extended hose. Maybe you could come up with some cleaver thru-hull snap-on attachment if needed instead of running it through a port or hatch if you felt that was useful.

Freezer - The small difference in power draw is probably less important than size and weight. I doubt anything bigger and heavier than the 28 is practical on a Triton but maybe you can make the 35 work. Dual voltage option may be a concern for you or not. Since heat rises, top venting is essential but would be helped by vent holes in the forward panel, and less so by vents into the lockers on each side unless they are well vented themselves because in a couple hours the heat builds up. I don't know if you can fit batteries and a freezer in that space. Another consideration is the loss of storage in that handy locker and since it's in a saltwater spray and drip zone you need to place a bog over it at sea that might interfere with venting.

I carried two folding bikes in the v-berth for a couple years. It was a hassle but seemed worth the trouble for long distance shore excursions. Mine are cheap, now broken, West Marine bikes I bought used. Thanks for the heads up on Brompton. Looks like a much better option than most of the others I've seen.
HinduKush
Bottom Paint Application Technician
Posts: 18
Joined: Thu Jun 11, 2020 1:30 pm
Boat Name: Hindukush
Boat Type: Pearson Triton

Re: Integral water tank build

Post by HinduKush »

Hello,
I was cutting plywood this afternoon from the templates. Also installing two exterior doors on the house cutting out block wall and windows onto porch.

I did see that video on Dawn Treader and their leak at the rear Beckson plate. I listen to other peoples ideas so if I like somebody's idea better than my original plan I adapt to it or tweak it a little to suit my goal.

I think I will do the bilge tank and aft tank. I was worried about the diesel slime eventually seeping thru and into the fresh water?

The bilge water looked like it had been there for years by the looks of it. You have seen it before so no description necessary. I also had some more spill when I removed the old diesel tank and cut water line inadvertently from original bow tank and had a good mess to sop up. I didn't want to gum up my shop vac so I decided to try Size 6 Huggies diapers for toddlers up to 35 pounds. It said they hold about a liter each and they do. I probably had 5 to 10 gallons of sludge in the bottom. Pack of 62 diapers soaked
It up about 98 percent of it. I was happy at the 24 dollar price then and clean shop vac.

My next goal is to first try to fill in the 11 or so holes in the cockpit. I will use the old 3/8 ply from inside the original boat backrests. Would that be ok i.e. for the make up where the ice box cover was over the 1/2 ply. Like in your video. If so then I will use it on the other holes when I beef up under cockpit with 1/2 inch plywood.

Yeah the bike location is easy to switch. My second thought because they fold so small was to put a small shelf inside Vee Berth on each bulkhead wall by lockers and they should fit high enough for head or feet clearance. Strapped in. Then when using alot just locked up on deck.

I think your right about the cooler box location with spray and ventilation issues maybe more hassle than benefit. So If I can put bikes in Vee berth then mount cooler on slide out shelf so access to medics cabinet is better and still have hanging locker space above on each side plus cabinet storage

I think I will still go with the vee berth head location.and chain locker vent if I use one.. I was sitting on the vee berth seat and thought using those holds like you put on each side of the companionway and the single holds under the dodger on top of cabin on Osprey think it was. I thought that seems stable and the head hidden. I would be more prone to use your idea of a dishwashing liquid container for urine elimination.

The shower idea was inspired by those tube showers (link below) they put on the side of adventure SUV's roof racks like in Australia. They have a bunch of DIY videos to make them. Really not complicated to do. You pump up with a bicye pump using a schraider valve to 15 psi. I would just open hatch set tube on the deck for an hour. So use it in either in the cockpit or inside Vee berth idea. Have flexability to each location considering general weather conditions, sea or air temp etc.

Thank you again for your support and help. I really appreciate it Sir.

Here is a link to the tube solar showers they are about 6 gallons I would make mine 2 or 3 gallon size. I think it would stow nice verticle inside starboard hanging locker in a corner.

https://www.rei.com/blog/camp/diy-car-t ... amp-shower
HinduKush
Bottom Paint Application Technician
Posts: 18
Joined: Thu Jun 11, 2020 1:30 pm
Boat Name: Hindukush
Boat Type: Pearson Triton

Re: Integral water tank build

Post by HinduKush »

Hello,
This Solar shower I would tweak. I didn't think schraider valve install was good. And use a low volume spray head. I do think this is easier to repair and stronger than a shower bag. I still like the garden sprayer idea and would probably have the hand held small half gallon house plant sprayer for rinse after salt shower etc
This video is just example of a build a concept.

. https://www.rei.com/blog/camp/diy-car-t ... amp-shower
User avatar
atomvoyager
Moderator | Revitalizer of Classics
Posts: 421
Joined: Thu Jul 12, 2018 7:48 am
Boat Name: Atom
Boat Type: Pearson Triton
Contact:

Re: Integral water tank build

Post by atomvoyager »

I'd wash out the bilge with detergent and water and rinse. Then once dry scrub it good with acetone on an old towel. Then add a single layer of fiberglass cloth and plenty of resin and there is no chance of old oil contaminating the tank.

Using 3/8 ply underneath to close the old icebox top could work along with 1/4" to fill the top if attached well enough. If in doubt use 1/2". You never know when a heavy crew might come down hard on it.
HinduKush
Bottom Paint Application Technician
Posts: 18
Joined: Thu Jun 11, 2020 1:30 pm
Boat Name: Hindukush
Boat Type: Pearson Triton

Re: Integral water tank build

Post by HinduKush »

Hello,

Sorry to beat a dead horse with bilge tank questions. I think I would go with the Diviniycell foam for tank top and baffles. The only concern I have is the lead keel and lead Leeching thru the fiberglass into the water tank? I researched the Allied Seawind 30 and she had a lead keel as well. The Alberg 30 had the iron keel which would make it a better candidate?
User avatar
atomvoyager
Moderator | Revitalizer of Classics
Posts: 421
Joined: Thu Jul 12, 2018 7:48 am
Boat Name: Atom
Boat Type: Pearson Triton
Contact:

Re: Integral water tank build

Post by atomvoyager »

If the tank is not leaking and well sealed with fiberglass/epoxy then I don't believe there is any chance of lead leaching through. If nervous about it just put an extra layer of glass and couple more coats of resin. Since none of us here can do molecular testing we rely on whatever testing others have done, our experience, and common sense. After all, epoxy is used to stop osmosis in fiberglass which I suppose is not unlike some chemical leaching process. Maybe you can find online reports of tests done somewhere related to fiberglass/epoxy resin panels ability not to allow leaching and get back to us with what you find. Then you have the final coats of Bar-rust epoxy which is certified for potable water if mixed in the right ratio. Then you have the charcoal water filter. Some of these filters will also greatly reduce lead to safe levels so you can research that too.
HinduKush
Bottom Paint Application Technician
Posts: 18
Joined: Thu Jun 11, 2020 1:30 pm
Boat Name: Hindukush
Boat Type: Pearson Triton

Re: Integral water tank build

Post by HinduKush »

Hello,

I did look up but couldn't find if lead leech's out thru fiberglass. I did look into the inline filter systems. Like the Woder inline filter looked good.

If I did decide to go with the bilge tank where would you start the tank at the main aft main cabin bulkhead (bookshelf and head) back to companion way steps?

I am still not opposed to the Atom or Osprey set up. Looks like a forward tank will be easier to build.
User avatar
atomvoyager
Moderator | Revitalizer of Classics
Posts: 421
Joined: Thu Jul 12, 2018 7:48 am
Boat Name: Atom
Boat Type: Pearson Triton
Contact:

Re: Integral water tank build

Post by atomvoyager »

You don't need to search lead specifically because there is nothing special about the properties of lead. You might be confusing lead in direct contact with water in a lead pipe for example. In your case you are concerned about lead contaminated keel water separated from the water tank by thick fiberglass and numerous coats of epoxy resin. You can search for water permeability of epoxy because in your case the water might carry lead. In reality you don't need to bother because it's not gonna happen. The only likely contaminant you could get is from poorly mixed final coat of Bar-rust sealer because that is the only thing the water in the tank will be in contact with. Care in mixing and a good filter would eliminate any problem with that.

In an earlier post I said the main bilge tank could start at the forward end of the head compartment just aft the step into the forward cabin and run aft as far as you can go while still leaving some space for bilge water in the aft main cabin between the two tanks. Then later I added that 72" is the maximum length that fits. You could also start the tank further aft at the forward cabin bulkhead where it meets the head compartment if you have a reason to but would need to subtract that difference from the 72" in order to maintain a place for bilge water between the tanks.
Post Reply