Painted fiberglass water tanks: how to clean/maintain?

[Transpac]

We have a 1986 Transpac Eagle 32 that's relatively new to us. We just pried open the cover to the water tank and discovered that it's actually four connected chambers, but we've only got access to one of them. The tank(s) is painted fiberglass and doesn't actually look too bad, but I found a few paint chips at the bottom. Eww.

Is there any way to get the tank up to snuff so we can have potable water? Do we need to create access and repaint every chamber?

 

[jungpeter]

Hi Transpac,

Well, that's a tough one to answer without being you, and being there! Never having seen the guts of an Eagle 32, I am at a disadvantage. You say "eww", after opening your fresh water tank and observing a few paint chips in the (presumably) baffled tank you have access to. So what's your tolerance for "eww"??? A "few" paint chips is insignificant unless they're clogging your fixture strainers; only the water quality in your tank really matters.

Have you made a valiant effort to clean and disinfect your tank? If not, buy Peggy Hall's book on sanitation (https://www.amazon.com/Get-Boat-Odors-Peggie-Hall/dp/1892399156) and follow her instructions exactly on how to bring a water tank to a safe and sanitary condition.

Water test kits for bacterial contamination (NOT test kits for minerals, such as iron, copper or other typical water well contaminants) are available for about $20. You might try one to make sure your water is not simply fouled with sediments or paint residue. Or send a water sample to a municipal water testing lab for professional diagnosis of "eww".

If after you've expended due diligence to clean and sanitize your tank, and are still convinced your tank is unsanitary, then yeah, you will have to access EVERY PART of your tank to clean it completely. And assess the "paint" your OEM applied to the interior of your tank. Not sure why one would paint (and with what) the interior of a fiberglass fresh water tank, but who knows? If the tank was, as I expect, gelcoated at manufacture, the gelcoat may be failing and cracking. IMHO, A pretty tough DIY fix to get it right. You may well need professional assistance at this point.

Regards,

Pete

 

[Larry M]

Are you sure it’s a paint chip(s) and not a piece(s) of gel coat? We have fiberglass tanks and the inside is gel coat. I’m wondering why a manufacturer would paint over fiberglass. Have you talked to other Eagle owners?

If you can get a chip, rub it on a piece of sandpaper and smell it. If it’s gel coat, you’ll recognize the smell.

 

[Comodave]

We had a previous boat with gel coated interior fiberglass water tanks. The gel coat started breaking down. It would clog up the filters and the strainers on the faucets. We finally replaced them with some custom plastic tanks. No more problems. I would be surprised if you will be able to clean the inside good enough to be able to coat them again and use them as potable tanks, but I am not an expert on water purification.

 

[FF]

The "paint" may be a proper approved coating for potable water .

Ignore its tiny failure spots , just install a house filter before the water pump.

 

[Pack Mule]

Just had same problem with our tanks, but ours had leaked through and into a bulkhead , not good. I wanted to make at least one tank potable. I finally found a tank at Ronco that would fit through my deck hatch and kinda fit in the area but I had to give up a bunch of capacity. I’m installing it now and it’s about to whoop me. This is one job I should’ve let the yard do and picked up the boat when done. Good luck with your repair.

 

[Transpac]

I think you're right and it's gelcoat. And once I read your comments I realize that, assuming the manufacturer used a gelcoat or paint that's approved for potable water, it doesn't really matter if there's a bit of chipping.

I'll buy Peggy's book and go through her process. Getting the water tested is a great idea (that I should have thought of)! That will make me feel much better...or worse, depending on the results, ha ha...about drinking the water. Thank you all so much for your comments!