water tanks, clean or replace

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bleacherfan

Member
Joined
Sep 26, 2019
Messages
8
Location
usa
Vessel Name
Chacha
Vessel Make
1972 Grand Banks
I want to drain, clean and replace water on our two tanks my husband wants to replace tanks on our 36' 1972 GB. Cleaning them is that even a possibility? Trying to get away with doing less than we need to. Thanx for your help.
 
Welcome aboard. You might get Peggie Halls book from Amazon. It has cleaning tips for lots of things on the boat. You can clean or at least sanitize the tanks. What is wrong with the tanks that they might need replacing?
 
My husband said it doesn't hold pressure and theres a leak in the line to kitchen. Is that something that should have been found in the survey?
 
If there is a leak in the line, that's the likely reason for pressure loss. The tanks are likely stainless so with a minimal cleaning they should be good for some time. There should be access ports on the top of them for getting inside to wipe them out.
 
I became aware that we had a dirt in the tank problem so my cleanout procedure.

Change the hose. THey do need that from time to time. Even the filler hoses need to be changed. All hoses deteriorate. Even the clamps may need to be tightened as hoses take a set,[ shrink] allowing air and water to leak past preventing any pressure test working. Be cautious as even 3 PSI is enough to damage a tank. They are not built to hold a lot of pressure.

THe deck fills may not hold pressure even if they are the type with an O ring for a seal. They are not designed for that, rather to simply block deck water from entering.

Aha, did he remember the tank vent. If not and he didn't close/block it the tank cannot hold any pressure which is actually the intention.

Do you need to clean the tank or sanitize it? Cleaning can be accomplished with some work, maybe a bunch. But if it only needs cleaning and not replacement the work of cleaning will be far, far less.

Without knowing how dirty your tanks are I will suggest what I had to do.

I bought an old , used Jabsco diaphram pump and rigged it with a copper dip tube that would hit the tank bottom through the deck fill. The bottom was cut for about a 45o angle so even when on the bottom it was not closed off. Of course my fill was straight in.
THis will save the onboard pressure water pump from a lot of running and I would rather ruin a cheap yet still decent pump than my onboard one.
Further it doesn't load all the plumbing with the dirt I am trying to dispose of.
The copper tubing I used was flexible,soft copper so it can be tweaked a bit which I needed to be able to go down. Comes in a coil it needs to be straightened.

I filled the tank about half full. No more than about half or the agitation will be hampered. THen I mixed up some no suds laundry detergent, 1/2 cup, and water in a two gal. bucket and poured that into the tanks. Note I added some water, then added the soap/water mix, then finish ed the tank 1/2 fill so the soap was mixed in.

Took the boat out on a rough day, not dangerously rough, but enough to seriously agitate the water in the tanks. Pitching, rolling, bow into the waves, stern into the waves. Spent 1/2 hour bouncing about and then used the pump to empty the tank and the now dirty water.

I went back in with the now empty tanks and refilled to full and went out again. More bobbing about and then started the pump again. This will flush the soap and any last dirt out unless the dirt is quite large and to heavy. Untill the tanks were empty again.

Refilled and when I did a taste test I could detect a very faint soap taste.
Ok, dumped it but at the dock this time.

Again refilled but this time I added a gallon to each tank of denatured alcohol after about half filled to again ensure mixing. Topped up the tanks. Went out again and bobbed about and came back in after emptying the tanks.

NO soap taste this time. The alcohol was an idea I read about. I though iI had bookmarked the article but I cannot find it, yet.

If you wish do one more fill and empty cycle but at least this time you should not have to go out.

Now the last thing I will suggest. Use filters to stop any new dirt from getting into the tanks. I use and have used now for many years a 5 mic spun poly pro filter and then a ceramic filter. THe ceramic will produce slow filling but it sure catches any dirt.

If you have large tanks, mine are 50g each [2], you may want to parallel the ceramic units or look for a larger element unit than mine. They are around. Both my filters are the standard 2" diam x 10 long units.

Other may suggest other combinations. The main thing is to not put any more dirt into the tanks when refilling.

I agree about Peggy Hall's book. Look it up. Her book covers sanitizing very well, at least to me.


Do a quick look through the posts as there is another thread asking for VERY similar info.
 
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The water tanks are not made to hold pressure and they actually have a vent hose that stops them from holding pressure. It is probably a leak in the plumbing or the water pump itself.
 
Get some non-chlorine bleach too. Publix grocery store.
I have some sort of plastic water tank with a bung fitting on the bottom to which I added a spigot for draining. I have 2 filters, one on the dock and one about 3 feet from the deck fill. So far everything seems to work out well.
 
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There may be a pressure tank in the fresh water system, something that looks like this (different size, shape, color, etc.):
PressureTank.jpg
Could that be what he's talking about replacing?

Greg.
 
Yes, an accumulator. Forgot about that.

A horizontal unit like that could accumulate debris.
A vertical mounting unit like mine where the inlet/outlet is on the bottom should not accumulate much, if anything.
 
bleacherfan,

Is any gunk clogging the filter screens or aerators on your faucets? If so, what does that look like? Any smell/color to the water?
 
I just went through this process with cleaning the freshwater tanks. Not quite done on fixing plumbing leaks. PO had put in Qest fittings, which I believe are for RVs? Anyway, lots of places for that stuff to leak. But a leak or two wasn't my main concern. I didn't know how long it had been since the tanks had been cleaned out and sanitized. I would like to have a system that allows drinking from the tap as well as good coffee.

Your tanks should have no pressure, positive or negative. They are simply a reservoir for your pressure system. Your pump pressurizes the system, but it has a backflow valve that keeps that pressure in the system and does not affect any pressure in the tanks. They are open to the atmosphere through a vent.

When removing one of my deck fills, I heard a tiny exchange of air psssst. That was suspect. I pulled the drain plugs from both tanks, which were close to empty and just drained them into the bilge. I put a white dinner plate down so that I could examine the last of the water as it came out. I also put the hose down in the fill and blasted water so that if there was any sediment in the tanks it would get flushed out to my dinner plate examination. I also caught some of the last in a clear glass. I didn't see a speck of anything.

I filled both tanks halfway and poured in 1/2 gallon of bleach into each 62 gallon tank. This isn't based on some calculation as to what percentage of sodium hypochlorite solution is required to kill certain germs or bacteria. I bought a gallon and had two tanks. I completely filled until water came out the vents. Water didn't come out the vent for the tank that pssssted. I removed the vent hose and found mud from what probably was a wasp's nest in the clamshell on the outside of the hull. That was cleaned and flushed with the bleach solution.

I ran the pressure system until I could smell bleach at each tap. This took awhile for hot because of a 6 gallon hot water tank. I then let the tanks and lines sit for two days. I thought about setting up my spare Jabsco 12V water pump to drain the tanks, but instead I just pulled the drain plugs again and the bleach solution went into the bilge. It took some time, but I had other projects, including checking out the bilge pump system. I even did a little scrubbing in the bilge with the bleach solution and let the bilge pumps get rid of that.

Once the tanks were empty, I put the hose back down the deck fittings and blasted the inside of the tanks again while using my "dinner plate and glass" examination system. This also served to further dilute what remained of the bleach. I put sealant on the drain plugs and started to fill again while running all taps. This flushed out the last of the bleach.

I forgot to even look at the cost of a gallon of bleach. But it is more the time (and not that much) that makes this a project. Best part is I'm not certain that my system is sanitary and I know that vents and fills are okay (I replaced one of the deck fill o-rings). Now I'm ready to address the few little leaks in the pressure system.
 
As an aside, at least in my experience, Qest was still sourced as parts for existing boats at least up to around 2005 (which to all appearances had been used originally). It is of the "family" of pb (polybutylene) plumbing, which has fallen out of favor due to many leaks and problems (in houses). It was also used in mobile homes and RV's. I think its heydey as new work ended around 2000 or so.

The replacement of choice is usually PEX pipe (tubing) with your choice of fittings. There are pb to PEX joiners, so it can be done a bit at a time (repairs, adding new).
 
Bleacherfan,
Marco got it right about the tanks. No pressure, they are vented to allow water to be drawn into the "pressurized" water system. Unless your tanks are leaking or are in bad condition (for example badly rusted) they probably don't need replacing. Repair or replace the line(s) that are leaking.
Basic cleaning of your tanks is just filling and emptying, and flushing as best you can or opening access ports for hand cleaning. Low tank openings work best for this draining/cleaning and using an "exterior" pump during the flushing can reduce the work on your boat's pump. As advised, filter all in going water to reduce any "dirt" (particles) from the water supply,and possibly be "fussy" where you take on water in the future. Ensure your deck fill "O" rings are new to seal the opening stopping contaminates from entering there.
Depending on the material of your tanks, you may not want to use bleach for "sanitizing" your system. If you have aluminum or plain steel you may want to use an alternative product that is not as hard on the tank material. I have aluminum tanks so I use Thetford freshwater tank santizer.
The following is how to sanitize your water system using bleach.
[FONT=Arial, sans-serif]Always disinfect your boat’s potable water system at the start of each boating season and whenever water taste, odor or appearance becomes a concern. Before starting, ensure that the water heater is turned off at the electrical panel. Ice-makers should be turned on to allow the feed line to be disinfected. Remove any filter cartridges as well as any aerators at faucets. Flush the entire system with potable water and then drain it completely through every faucet.

Next, fill the entire system with a chlorine solution (0.13 ounces of common household bleach per gallon of tank capacity) and let it sit for four hours. You can reduce the contact time to one hour if you double the strength to 0.26 ounces of chlorine per gallon. Drain the entire system again, flush it thoroughly with potable water, and discard the first two buckets of ice generated by the ice-maker (if installed). Fill the tanks with potable water, clean the sediment filter installed to protect the pressure pump, and install new water filter/purifier cartridges as appropriate. Clean and reinstall the aerators at the faucets.

Visit
[/FONT]
[FONT=Arial, sans-serif]www.goboatingamerica.com[/FONT][FONT=Arial, sans-serif] to download a sample maintenance guide for sanitizing potable water tanks. You’ll also find several other documents that will be useful in developing a comprehensive maintenance program for your own boat. [/FONT]
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I also suggest buying Peggy Hall's book. She describes the entire process. Do not let the bleach sit too long in the system and do not use too much bleach. There is no need to fill the hot water tank with the bleach solution, leave it "bypassed". Rinse/flush well after using the bleach.
Replacing tanks is often a difficult, time consuming job that is usually a "last resort".
Good luck.
 
It's quite possible the QEST stuff was original. My boat has all poly-B and QEST plumbing from the factory. I'm definitely planning to start replacing it bit though, as 34 years is a pretty good life for that stuff and I don't know how much more it's got left.
 
There is no pressure in the water tank.
Water is sucked out by the pump, pressurized by the pump into the accumulator tank. Fom there to the faucet it is under pressure.

There is usually a filter screen between the tank and the suctions side of the pump that can be plugged.

The tank and all hoses can be cleaned to use for drinking following Peggy's instructions. I always did it at least once per year.
Unless the tank itself is actually leaking they rarely need to be replaced. Simple system once understood and easily repaired.
 
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I want to drain, clean and replace water on our two tanks my husband wants to replace tanks on our 36' 1972 GB. Cleaning them is that even a possibility? Trying to get away with doing less than we need to. Thanx for your help.
My ‘98 GB had 2 aluminum water tanks - with fill caps under the lazarette hatches, no deck fills. The tank outlets are outboard on each side and difficult but not impossible to access. So if leaks are the problem, trace the waterlines (2 lines join to a common supply line) to the ER water pump.

Cleaning? You have a taste issue? Usually Peggy Hall’s method sanitizes the tanks well BUT if the previous owner had the habit of adding a bit of bleach to keep the fresh water clean, there may be serious corrosion of the aluminum tanks leading to a thick layer of AL based sediment in the tank, which leads to the taste issues-of course more CL just makes it worse. Because of the baffles, cleaning the tanks is next to impossible. Leaks from the tanks are the terminal symptom requiring replacement. This is relatively easy in the GB42 which has 3 Aft tanks against the transom. removing The middle 1 allows the outer tanks to be slid in board. On my 36, - no room to slide, had to dismantle all steering gear, drop the rudders, and cut 1st tank to get it out, then can remove the 2nd. I Replaced both with custom poly tanks slightly smaller than OEM in order to get them in. Build a mock up in plywood of exact replacement before you order new tanks, to ensure you can install them!
 
There may be a pressure tank in the fresh water system, something that looks like this (different size, shape, color, etc.):
View attachment 102723
Could that be what he's talking about replacing?

Greg.

This type of tank is used on domestic applications with a pump sitting on top.
I suggest you go to West Marine, search on accumulator tanks. Depending on your application and space, get the reasonably largest tank, that will fit. Once you determine the size, go hunting for the best price. Per mounting, on my N46, I used an over size accumulator tank and mounted a vertical tank and mounted it to conform to the angel of the hull, never had a problem. OR, I suspect one can mount 2 smaller accumulator tanks. Per pressure of the accumulator tank, forgot.
 
Wow, a lot of lengthly answers. All good.

Let me add a short note.

If the tanks are stainless steel, don't even consider replacing them. Follow any of the above advice and just clean them up.

Mine are S.S. I used to get rust particles that would plug the filter and the screen on the faucets. I can't imagine where it came from. All I could guess was that it might have been slag from the welding of the tanks.

I bypassed the filter and removed the screens, simple.

We don't actually drink from our boat tanks. Maybe a toothbrushing rinse or a pill needs washing down. We do cook spaghetti and boil corn with the water though.

BTW, (Hmmm, here I am getting long winded again) A 1972 G.B...Tell us about your fuel tanks. If you are anxious to replace any tanks, the fuel tanks should be your first challenge, unless you have already done it. They are "ripe" for failure.

pete
 
The replacement of choice is usually PEX pipe (tubing) with your choice of fittings. There are pb to PEX joiners, so it can be done a bit at a time (repairs, adding new).

I've got my PEX all ready to go. It is actually Pex-Al-Pex left over from when I built a house with hydronic heat in the floor slab. If you aren't familiar with P-A-P, Google it and take a look. It is popular with hydronic heat because you can bend it to make a grid without tying it in place and then pour concrete over it. Working with regular PEX is like wrestling a boa constrictor. P-A-P cuts easily with a regular PEX tube cutter. I've even used P-A-P as conduit for small electrical wire runs on board. Put the wire in the conduit, bend it to make the run, attach. Good stuff to have around. It is cheapest in 100 meter rolls, which is a lot. I had 140' left over from the house build so I have plenty left to redo the FW on my boat.

Fasteners and fittings have improved over the years. Home Depot and others have Sharkbite "push on" fittings are convenient but really pricey. SS bands on traditional brass fittings are now cheap, as is the tool that compresses them.
 
". It is actually Pex-Al-Pex left over from when I built a house with hydronic heat in the floor slab."


Is it listed for potable water?
 
". It is actually Pex-Al-Pex left over from when I built a house with hydronic heat in the floor slab."


Is it listed for potable water?

Yes, it is Pex on the inside and outside. The aluminum in the middle is meant mainly to be an oxygen barrier but it also works great for bending it without the need for hundreds of tie down clips as with regular Pex. It is stiff enough so that it can be fished through blind areas if it is straightened out. Regular Pex always wants to curl back up.
 
Is [Pex-Al-Pex ] listed for potable water?

I was just thinking the same thing this morning and had it on my list of things to look up.

The way I get around the Gorilla wrestling is to buy PEX in straight "sticks" instead of coils. Not sure how long a single stick can be but I've bought 10-footers easily (didn't need longer uninterrupted piece though). I've found it at common DIY home stores.

The described "Gumby," stays-bent-the-way-you-bend-it property of the Pex-Al-Pex sounds handy if it is ok for potable water.

Edit: I see Marco posted and said it is rated for potable water. So I guess it has a smaller ID for same "size"? That would be fine for me as I could have used 3/8" but used 1/2" just because it's more standard and easier to find.
 
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I replumbed a previous boat with Sea Teck pipe and fittings. The pipe was sold at West Marine in coils. You could not get it to straighten out. So I got them to order 10’ sticks of the pipe and it was wonderful to work with. I had to order it in quantities of 10 sticks. They also had 20’ sticks but you had to order a gross of them and I didn’t need anywhere near that much. But working with the straight pipe was so much easier than trying to uncoil it.
 
I did a bit of looking and I see the Pex-Al-Pex can be used with compression fittings or (I think?) the band type fittings. But not* the quick push connect type.

I don't have too many fittings, so am going SeaTech 1/2" push on (quick connect) fittings. (Went 1/2" vs. 15mm so I could get PEX sticks at box store, or even fittings in a pinch.)

*It looks like one brand now has a way to peel off the outer plastic on Pex-Al-Pex so you can use push on fittings, but not sure I'd want the exposed aluminum. I think I'll stick with what I have planned for now but the Pex-Al-Pex looks like an interesting option. Thanks for mentioning it, Marco.
 
When I did the FW plumbing in my house, I used the old copper band system that was swedged over the PEX on to the brass fittings. I recall that I paid about $100 for each of the Zurn brand swedging pliers (3/4, 1/2, 3/8). I used the same tool and fittings for 1/2" PAP in the floor.

After the build, I easily sold the pliers on Ebay and then worried that I might have to do some repairs in the future. Well, the future is here and I'm glad I sold them.

For the boat project, I just bought a crimp tool and a supply of SS rings for $25. The tool works on all sizes of PEX clamps. Times have changed.

The pu$h on fitting$ are expen$ive and no faster than the crimp rings. They can be great if you have an area that you can't reach with the crimper (although a little forethought in assembling the tubing can usually eliminate this problem). The only one I used is a SharkBite push-on back flow preventer (which fits just fine on my PAP system). Those can go bad after a decade (I found out) and are quick to replace.
 
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Sandpiper has 3 SS water tanks, 400 gallons total. I do a shock treatment once a year in the spring, which is 1 cup of chlorine per 100 gallons. I pump it through the system and let it sit for a couple hours, drain refill and drain again.

I drain the water/bleach into the bilge, which does a nice job of disinfecting, cleaning and deodorizing the bilge as it gets pumped out by the bilge pumps.

When we purchased Sandpiper, the tanks had not been cleaned in 24 years. Opened the 12" X 12" inspection port on top and scrubbed the interior of the tank with a Scotchbrite pad on a stick and flushed it out with water.

I have an easier way to clean now. About every 5 years I open the inspection port and clean the interior using a pressure washer. I have a wand with a 90° bend in it and I stick that through a hole in a clear plastic 12" x 12" plate that goes over the inspection port. I move the wand around with an up and down circular motion for about 10 minutes and the interior gets pretty clean. I stop the water every so often to let the draining water catch up.

I add bleach to the water tanks, 3 teaspoons per 100 gallons to keep the water fresh. Not every marina has chlorinated water.

We have a separate water faucett at the sink for drinking water only and it's connected to a microfine filter that takes out the chlorine taste and odor.
 
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To cramming I took off the clean out on top of the tanks and sucked all the water out with a shop vac. Cleaned and disinfected with bleach and refilled. If you have a leak it can be easily fixed with epoxy putty on the outside of the tank. Tanks are usually stainless so the only place they leak is at the welds. If a line is leaking then you can replace the line. If it is difficult to get to reroute it
 
If the tanks are aluminum or SS why can't you use hydrogen peroxide instead of bleach? You can get it in 12% by the gallon really cheap. Just wondering.
 
If the tanks are aluminum or SS why can't you use hydrogen peroxide instead of bleach? You can get it in 12% by the gallon really cheap. Just wondering.

Bleach at $2 to $4 per gallon is a lot less expensive.
 
You can. It is an immediate cleansing of the tank but does not effectively treat the water as chlorine does
 
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