Oily film in water tank.

[Geftb]

Hi all, i have a ply/glass, two pack poly finished water tank. I contacted the maker of the paint before using it in a and he said it is fine, food grade etc.
the first few times i filled it was from a regular garden hose and have since purchased a proper water hose.
Right from the start it has had an oily film inside of it, bad taste, (just use it for washing) and i have not been able to remove it.
Tried warm soapy water, vinegar/bicarb, bleach, some stuff i purchased from the chandlery, and it just wont go away.
Any tips?
cheers
Steve

[Andrew Donald]

What about a vinyl bladder??

[Geftb]

I would prefer to find a solution, but yes, thats final resort. Remove the ply/glass tank and install a bladder.

[Boatsbgood]

Bladder inside tank, access hatch at top?

[JimConlin]

Is it possible that the. 2-part paint or the (assumed) epoxy under it was mixed off-ratio? If it were, the over-represented component will leach out for a while. I’d wait a while before doing anything drastic.

[Geftb]

Is it possible that the. 2-part paint or the (assumed) epoxy under it was mixed off-ratio? If it were, the over-represented component will leach out for a while. I’d wait a while before doing anything drastic.

Hey JIm, thanks for your reply,
Yes it’s epoxy. I washed the blush before epoxy primer, let it dry, sanded and washed with water before applying the top coat. Mixed in a measuring cup. Could i have made a mistake? Its happened before. but its been over a year now with many different cleaning approaches (noted above) tried.

[willin woodworks]

is it possible that the its not the tank but your piping from the tank to the appliance?

[SchoonerRat]

Water filter. Not a bad idea even with a squeaky clean tank.

[sp_clark]

How big's (volume, in gallons or liters) is this tank?

One product I'd try is citric acid. Cheap enough and commonly available as LemiShine dishwasher additive, its uses are wider than just for cleaning dishes.

https://www.thespruce.com/citric-aci...g-uses-1707021

Another product that's used to neutralize leftover chemical residues in home and agricultural tank sprayers is Sodium Carbonate - Na2CO3.

A cousin of baking soda (Sodium Bicarbonate) it's less commonly available than citric acid. If you live anywhere there's an ag-supply store you can find it as a powder. Also sold as 'washing soda' but read the label first if you find it sold as such to ensure you're getting that & not something else.

If you can obtain either one then mix a water solution to spray down the insides of the tank when it's empty you'll save water and a lot of what you've bought for later use. Leave the solution sit for a few minutes then rinse with fresh water. (I had a couple pounds of Sodium Carbonate left from my days mixing photo developers. Found it's now classified as a hazardous substance – in that it's a strong oxidizer, why it's effective in solution for cleaning stuff – when I went to drop it at a local collection site. Then it dawned on me it's safely and easily disposed of after being neutralized with hydrochloric acid (any acid for that matter). The reaction produces Sodium Chloride, CO2 and water once the reaction's complete. What would have cost me $50 in fees for disposal of ended up costing me $6 for a quart of hydrochloric acid.)

Use proper PPE when handling these chemical please. In high concentrations both can irritate your skin if left in contact for long. Gloves and eye protection would be minimum recommended during their handling and usage.

[Geftb]

is it possible that the its not the tank but your piping from the tank to the appliance?

Hey Willin, i fill directly into the the tank with water grade pipe. But you have me thinking, it may be the piping from the faucet itself.
its an old marina…?

Cheers Steve

[Geftb]

Water filter. Not a bad idea even with a squeaky clean tank.

Hey SR, next step!!
Cheers
Steve

[Geftb]

How big's (volume, in gallons or liters) is this tank?

One product I'd try is citric acid. Cheap enough and commonly available as LemiShine dishwasher additive, its uses are wider than just for cleaning dishes.

https://www.thespruce.com/citric-aci...g-uses-1707021

Another product that's used to neutralize leftover chemical residues in home and agricultural tank sprayers is Sodium Carbonate - Na2CO3.

A cousin of baking soda (Sodium Bicarbonate) it's less commonly available than citric acid. If you live anywhere there's an ag-supply store you can find it as a powder. Also sold as 'washing soda' but read the label first if you find it sold as such to ensure you're getting that & not something else.

If you can obtain either one then mix a water solution to spray down the insides of the tank when it's empty you'll save water and a lot of what you've bought for later use. Leave the solution sit for a few minutes then rinse with fresh water. (I had a couple pounds of Sodium Carbonate left from my days mixing photo developers. Found it's now classified as a hazardous substance – in that it's a strong oxidizer, why it's effective in solution for cleaning stuff – when I went to drop it at a local collection site. Then it dawned on me it's safely and easily disposed of after being neutralized with hydrochloric acid (any acid for that matter). The reaction produces Sodium Chloride, CO2 and water once the reaction's complete. What would have cost me $50 in fees for disposal of ended up costing me $6 for a quart of hydrochloric acid.)

Use proper PPE when handling these chemical please. In high concentrations both can irritate your skin if left in contact for long. Gloves and eye protection would be minimum recommended during their handling and usage.

Hey SP_,
I will give that a go and add a water filter before re-filling
Thanks all!
Steve

[Larks]

Hi all, i have a ply/glass, two pack poly finished water tank. I contacted the maker of the paint before using it in a and he said it is fine, food grade etc.
the first few times i filled it was from a regular garden hose and have since purchased a proper water hose.
Right from the start it has had an oily film inside of it, bad taste, (just use it for washing) and i have not been able to remove it.
Tried warm soapy water, vinegar/bicarb, bleach, some stuff i purchased from the chandlery, and it just wont go away.
Any tips?
cheers
Steve

Hi Steve, are they epoxy or polyester resin tanks? The norm' seems to be polyester for tanks rather than epoxy and the finish coat/flowcoat, that essentially makes it waterproof, wouldn’t need further painting.....??

[Geftb]

Hi Steve, are they epoxy or polyester resin tanks? The norm' seems to be polyester for tanks rather than epoxy and the finish coat/flowcoat, that essentially makes it waterproof, wouldn’t need further painting.....??

Hey Greg
I have used epoxy/glass, epoxy primer, and 2 part polyurethane paint. (Norglass, i called them and they seemed to think it would be fine.
It was all made from left over materials that i had on hand.
Cheers
steve

[wizbang 13]

Two part poly paint in a water tank?
I would not even use that below the waterline of a trailer boat.

[Geftb]

Two part poly paint in a water tank?
I would not even use that below the waterline of a trailer boat.

What can I say? I contacted the manufacturer before proceeding and they informed me it was good to go???