We made several attempts to get our water tanks serviceable for drinking water without success. We had bleached them and blasted them out as much as we could with dockside water, but the water tasted bad after sitting just overnight. Yesterday we removed the starboard settee to expose the tank. We made 3 cutouts for 6" Beckson screw in deck hatches. The tank was pretty nasty forward of the rear baffle. The good news was that we did not find any blisters or loose baffles. Wanda washed it out with Lysol- it cleaned up easily. Lots of flushing with fresh water. We installed a hatch in each section of the tanks. This will make an annual scrubbing easy. The hoses have the same brown stuff in them that was in the tank. We ordered a 75' roll of hose through Ace hardware. It was cheaper to buy the roll than buy it by the foot. Today we plan to reinstall the starboard settee and get started on the port side. I think we are on the road to improving the quality of our onboard water by quite a bit. Our bow tank is cracked in several places, I cut out for an 8" hatch there and got the prep grinding done inside the tank some time back, but got sidetracked and will get back to it later. We have a Katadyn Powersurvivor 80E water maker that I will eventually install and plumb up to put the product water into the bow tank. We will then transfer the water as needed to the port and starboard tanks for use. By doing this, if we blow a membrane in the water maker, only the bow tank will be contaminated with seawater.
One of the things I am looking at is the 3-4" wide open space on the inboard side of the water tank. It runs the length of the settee and is about 18" high.You could store a lot of stuff in there if it can be made accessable. Has anybody figured out a good way to make that area useable? I suspect the port side is the same way.
No room for any storage on the port side other than forward of the tank. This tank was about the same inside as the starboard side. The forward baffle is loose, doesn't look too bad to repair through the new hatch holes. This tank has aready had some fiberglass work done on it. It looks like the top was put back on.
We replaced the tanks and installed an inline carbon filter that really improved the taste.
We have a double filter setup that that uses 2 10" filters that I pulled out of the other boat. I will probably install it with a coarse filter for the inlet and a carbon filter downstream. The carbon filters do work well.
In our tanks, the solids had to go or we would not have been able to carry enough filters to keep the system going. I think by the time we finish the tanks and change at least the hoses between the tanks and galley sink we will have pretty good water. Our boat sat on the hard with water in her tanks for about a year before we bought her. Plenty of time for the tanks and plumbing to get fouled.
Filters are good, and water taste like mineral water, no tank taste and no chlorine taste..
2 things though:
-would be good to use a little bleach
-use the filtered drinking water often (bacteria may grow, particularly without regular bleaching)
Ideally:
also cut the tank open, clean, and sand the interior. Apply 2 part epoxy paint that is specially made for potable water tank use.
Last Thing:
check out these products (or google inline UV filter):
http://www.excelwater.com for inline UV sterilizer. They even have a combo with carbon filter with UV sterilizer.
I've never used them, but would look into it seriously.
Phil
I completed installing 8" access plates in my port and starboard tanks. I did not do anything to the bow tank since I have not used it for more than 8 years.
The most challanging issues were:
To cut out the openings in the plywood sections above the tanks in such a way that they would look like the original openings. I'm satisfied with the results.
The other to measure carefully to assure I did not cut the opening on top of the baffles. I cut off about 1/4" off one of them, no great shakes.
Like Ray and Wanda the tanks were awfull. I cleaned them by using about three gallons of bleach, SpicnSpan and lots of elbow grease.
I too want to paint the interior with an two part epoxy paint, but have not been able to find anything for use with potable water. If anyone has found a source I'd appreciate hearing from you.
I'm looking forward to next season with water that can be drunk without a blindfold.
Henri Hali
SV Windrider
We shock bleached ours (don't remember the concentration) and always bleach whenever we fill ( 4 tablespoons per tank). The nice thing about bleach is that it evaporates so there isn't much danger of over bleaching your water. Our "filter" (what I would call a large particle filter) occassionally fills up with stuff but the Brita seems to take care of most of the taste and fits nicely on the shelf behind the stove. Perfect? No....but it works for us.
I have what appear to be litle cracks in the water tank gelcoat. A little bit smaller than a dime in size. Several of them throughout the tanks. Appears some type of crud oozes from these little cracks. Also get some red colored crud sitting in the bottom of the tanks. I fear some type of chemical is leaching from the fiberglass and am fearful to drink the water. Am I being overly cautious?
Sounds like blisters. They can leach glycol? into the water in the tank. I would look at drying out the tanks and grinding the blisters out and repairing them. If they are small, you may be able to do it with a Dremel tool. I don't remember the full procedure, but there is plenty of info available on blister repair on the internet. You could work on one tank at a time and still use the boat as the work goes on. The current wisdom is to use epoxy to seal the inside of the tank, like barrier coating a hull. It is better than gelcoat. After all, good gelcoat only lasts about 30 or so years...
Blisters were my biggest concern with our tanks. Had I found them, I would have went to work repairing them. As far as sealing the repairs, I would have compared the costs between gelcoat and epoxy. If the epoxy was not too much more, I would have gone with it. By the same token, I would not be afraid of good quality gelcoat either. They would last as long as we're gonna need'em.
"After all, good gelcoat only lasts about 30 or so years..."
That's not really right. Good gelcoat properly applied lasts a long time. The point I was trying to make is that it has lasted 34 years in our tanks- if I had to do repairs inside the tanks, I would not be afraid of using gelcoat in them again. The key is buy high quality materials and apply them like the manufacturer recommends.
Does anyone have any leads on suitable epoxy paint for water tanks? The only NSF/FDA paint I've found is only approved for 1500 gallon tanks and larger (if you read the fine print). I found some paint called Brewcoat that appears to fit the bill (for fermentation tanks) but it seems a little dodgy and there aren't a whole lot of references for it. Any ideas?
I've cut the tops off my tanks and have been using bladders for the last few years living aboard but they've both ruptured (twice) and they aren't exactly cheap. Ideally, I'd like to rebuild my old, integral tanks rather than going with a smaller removable tank but I've hit a dead-end as for as epoxy.