Water tank crud

[jhgullett]

There is black mold/crud in the fiberglass water tank.
Tried bleach and detergent but it won't all come out.

Is there any special treatment to clean out fresh water tanks without removing from the boat ?
(daunting task in A27SC - might have to remove the engine...)

Would prefer not to replace tanks with two smaller tanks as mentioned in someone's
earlier post where a water tank was cracked and had to be replaced.

Thanks for any helpful suggestions/experience,

John
South Yarmouth MA

"Commodore Small" pending name change...
Still on the hard. Two new fuel tanks from Luther's in Bristol RI; cannot say enough good
about them. Rewiring AC and DC. new starter. etc.

[don123]

If you're hoping to ever get it clean enough to be able to drink the water, I think you're probably going to be forced to replace the tank
If you're OK with never drinking from it, I think I would fill it with water with a little detergent and 1/2 gallon of bleach and then use an aquarium air pump to inject air bubbles (to agitate the solution) into the outlet port at the bottom of the tank and let it bubble away for 3 or 4 weeks and then drain it and flush. Might be a good idea to drain and flush it once a week so you can see what's coming out. When it starts to clear up, it should be clean enough then to use for showering, etc

Don

[jhgullett]

Thank you Don.
That is more bleach than we were using.
Will get started on this program and see if anyone offers
any other magic chemical solution.
John

[JFOkie]

JHGullett,

My water has strange smell that I haven't been able to get rid of. I've tried bleach a number if times, I think that there is some sort of deposit crud on the bottoms of the tank; it's a 1987 FC with the original tank.

A friend of mine told me to put in marbles and then cruise for a few days. The though being that the marbles would roll around in the tank and loosen up the crud. Then, pump out the tank. The idea sounds interesting, but I'm not going to attempt it.

I'm going to try and remove the tank in the fall....or spring....and will probably have to install a new tank; I don't think I would be able to get the tank as clean as I would like. Also, I would hate to remove the tank, clean it, replace it, only to have it start to smell again in a year or two.

You shouldn't have to remove the engine, it will be difficult, but you should be able to remove the tank. If you're going to replace the tank anyways, it may be easier to just cut it up to remove it.

Good luck.

John
M/V Nirvana

[JFOkie]

Take a look at the A-27 Head Modification post. The most recent one talks about removing their water tank and has a few pictures.

This should help some.

John
M/V Nirvana

[jhgullett]

John,
Thank you. I went over and reviewed those posts. That is definitely a scene I hope not to see !
Marbles may take care of the bottom of the tank but may not help the sides. We are soaking now
with bleach.
John G

[Tree]

When i've removed water tanks in the past, so long as you can remove it after I have put rice in them to clean the sides of algae and gunk. It works a bit like an abrasive and has seemed to work perfectly for me - albeit on 25 litre tanks.

[Jay Knoll]

Why not cut a hole and install a clean out port like this one from Defender.


SeaLand Universal Holding Tank Cleanout Kit
3 Inch Inspection Port and Cap
Includes O-Ring, Gasket and Stainless Hardware
Installs easily on any rigid tank

Item #: 753760
Brand: SeaLand
Model #: 307238685
Shipping Weight: 1.00 Lbs.
List Price: $49.50



Our Price: $37.99
Status: In Stock

Quantity

Then you could hit the inside with a pressure sprayer and you'd be good as new

Jay

[jhgullett]

Tree: Will keep this in mind but am doing all I can to avoid removal.
Jay: Great idea. will look into this after one last try with bleach. I wonder if the o-ring which is ok for a holding tank will be ok for "potable" water. Will ask at Defender.
Thanks !
John

[Mark Deeser]

Never experienced this, but think if I found myself in that position I would remove water and steam clean in side of tank. I can not imagine anything what would survive that. But hey, that's just me.

[don123]

Mine didn't have the original tank when I bought it, so I'm not familiar with the materials/construction

*If* the tank *is* fiberglass, you do have another really good option. Use a drill with a 4 inch holesaw and cut a hole in the side of the tank where you have good access. You should then be able to get an arm with a brush inside so you can really scrub the inside of the tank with cleanser and then take a garden hose and thoroughly flush it out - I would disconnect the outlet port and let it drain into the bilge or a bucket to keep the crud/soap out of the rest of your plumbing system. You might need different size arms (wife, kids?) to be able to reach every square inch of the inside of the tank with the brush(s)

Once it's cleaned to your satisfaction, lightly sand the area around the hole and also sand the 4 inch piece the holesaw removed. Use fiberglass mat or a few layers of cloth and epoxy resin to replace the piece you cut out back into the side of the tank. I would cut a piece of mat about 8 inches in diameter and epoxy that to the piece, let it dry and then epoxy the whole thing back into the side of the tank. No question you could easily get a leakproof patch using this method . . . . assuming of course the tank is fiberglass. This would not work on a poly tank like I used to replace mine

I can only imagine what a job it would be to try removing and replacing the tank with the engine in place - I can't imagine that's the way Albin assembled these boats

Don

[djblackwood]

On previous boats I always added a little Oxi-Clean to the tank with each fill-up to keep it smelling fresh, but then we never drank from it. On our 29-year old Albin we add a cup of unscented chlorine bleach to half a tank of water, run it through all of taps until you can smell the bleach at each one and then let it sit 4-6 hours. It's best to take the boat out in some rougher water during that time for it to slosh around in the tank. Drain the tank completely, and then repeat the entire procedure with white vinegar. Again drain the tank completely and fill with fresh water. Then I install a new carbon filter in our inline filtration system. Fresh smelling drinkable water all season.

[jhgullett]

Jay, Don and DJ,

Thanks for the excellent thoughts. I found the Defender clean-out port kit and wrote to see if it is compatible with potable water as it is sold for a waste holding tank.

The tank is poly, not fiberglass as I originally thought.

Regarding the cleaning products and techniques, we are going to continue with our bleach soak for a while and perhaps follow that with the white vinegar while waiting to learn if the SeaLand Clean-out port sold by Defender will be ok with drinking water -even though we've been advised by many that it is better not to drink boat water, just wash up and shower with it and drink store bought water...

The reason for the port is that it is not practical to remove the tank or splash the boat at this point so the best option appears to be make a hole in the tank for access to clean, and then patch it or install a port.

Many thanks for the thoughts which are a path leading to a solution !

John

[DougSea]

On our 35 I cut holes in each of my aluminum tanks and power-washed the crud, and then put in sealed deck plates to close the holes. So far, so good.

viewtopic.php?f=7&t=6643

[don123]

. . . . even though we've been advised by many that it is better not to drink boat water, just wash up and shower with it and drink store bought water...

On my sailboat, I mounted a separate 12 gallon tank under a seating area just for drinking water and to use for cooking, making ice and beverages. It had a 4 inch screw port in the top and I connected it to a mini 12 volt pump which fed a separate mini faucet mounted at the sink. I used an in-line refrigerator icemaker charcoal filter between the pump and the faucet

We were very careful what we put in that tank - Always full of our home well water when we left on a cruise and we added 1/4 cup of hydrogen peroxide to keep the water from going stale. This was in addition to our 50 gallons of 'fresh water' which we used for showering and doing dishes

I think we'll probably use bottled water on this boat, but I haven't ruled out a separate 5 or 6 gallon tank for drinking water, probably mounted under the galley seat. On any boat which isn't being used regularly, it's hard to keep the large fresh water tank(s) clean enough for drinking

Don