Chlorine and effect on GRP

[Killick69]

Does anyone know what effect chlorine has on GRP. I want to clean the onboard water tank (GRP in sole of boat) and was thinking of using chlorine (bleach). Just concerned it might have an adverse effect on the fibreglass/gelcoat. What do you think/other ways to 'disinfect' tank?

[Dolphin]

G'Day John,
I think Chlorine would leave a strong smell and taste behind.
Most people use two table spoons of Carb soda in the tank when you fill it to kill any growth (swimmers). You cannot taste it when used for cooking. I only use the tank water for washing up and use tap water in containers and soft drink bottles.
Greg.

[Miker]

G'day John,

There are a few different products on the market, most are in the $20 range like Star Brite Water Conditioner, or Tank Cleen. Both available from your friendly local chandler.

My tank was pretty grungy, with some slime on the bottom, so what I did was to fill the tank half way, slosh some Tank Cleen around and then leave it overnight. Drain it into the keel bilge and then because it's supposed to be bio-degradeable and safe for drinking, pumped it out with the bilge pump.

You shouldn't use Chlorine unless you're going to capture the waste into a drum. Even after you've used chlorine, you'll need to rinse it fairly well. Once clean, re-fill and treat with the Star Brite or similar each time you fill up the water and it will be fine.

We also only use the water for cooking, tea and cleaning, never to drink fresh. Although you could at a pinch because it tastes quite OK.

We also have a Jabsco PAR-MAX 1 pressure pump feeding the galley faucet via an inline cartridge filter that we change every 6 months or so. Turn the tap, water comes out plus, when I get a round tuit, I'll add a deck shower for that lovely fresh water rinse after a summer swim

Unfortunately, I now find the paint/gelcoat is coming off the underside of the cabin sole, so have bits of it floating in the water. Another job, take the floor out and redo the gelcoat in the tank.....

Michael

[lockie]

This is a subject very dear to my heart, as I suffered horrible algal growth in the GRP keel tank of my Compass 28 for ages. Bleach won't hurt GRP (they sell it in plastic bottles) but failed to keep the wee beasties at bay for more than a few days despite some pretty strong doses. I tried a couple of proprietary water treatment products from Whitworth's, but they were no help.

I now use "Acquasafe" which is a product made by Davey (as in pumps) for potable rainwater tanks. It has hydrogen peroxide and traces of silver ions, works really well, and is only $40 for enough to treat 150,000 litres (ie one bottle for life). The water now remains crystal clear and is fine for washing etc. It is safe to drink but doesn't taste too flash, so I'll be putting a carbon filter in the line and it should be fine.

lockie

[bearmcnally]

Hi Guys

"Miltons" the go ? the stuff you wash baby bottles out with !

if that fails pour a bottle of "Johnny Walker" into it !

Cheers Bear