Dark spots in water tanks

[leveche420]

Any recommendation on what food-grade epoxy to use and where to find it?

[Copacabana]

Originally Posted by leveche420

The problem with popping and filling the blisters is that there are LOT of them and some are very difficult to reach...

Well, in that case I'd just recoat the inside of the tank with food-grade epoxy and forget about it. I can't see how the blisters inside the tank can cause any harm. In theory, the epoxy coating will seal the tank and prevent any new blisters.

[svHyLyte]

Originally Posted by leveche420

Any recommendation on what food-grade epoxy to use and where to find it?

See (click on) Masterbond Food Grade Epoxy

[Pete7]

Originally Posted by a64pilot

Actually I looked thru the small level sensor hole a couple of years ago. It was clean, except for what looked like calcium deposits.
It’s an aluminum tank.

Been there and got the t shirt with a previous boat. Aluminium tank eventually scrapped and replaced due to the dried dog food like rusk substance inside. Although I was able to get the tank out and use the pressure washer in the back garden to remove some it also turned the tank into a pin cushion with more leaks than a watering can sprinkler.

[a64pilot]

To replace my tanks, is about $20K.
Complete sole comes out and done correctly is made to be easily removable, then the tanks are replaced with custom made plastic ones.
I’ll nurse mine as long as I can, water quality seems fine, all drinking water goes through a sea gull filter, and all water through a 9” sediment filter.
I haven’t changed the sediment filter in over a year, and have no reduction in flow, so it’s not catching much.
It’s my understanding that chlorine reacts with aluminum and forms a nasty residue, and of course eats the aluminum. I have always filtered my water thru a carbon block filter slowly to remove the chlorine and when out, we make our own water.
I’ll nurse my tanks as long as I can, and they aren’t cheap or easy to replace

[Terra Nova]

Originally Posted by leveche420

Any recommendation on what food-grade epoxy to use and where to find it?

Originally Posted by leveche420

The problem with popping and filling the blisters is that there are LOT of them and some are very difficult to reach...

Use WEST epoxy 105 resin with their 207 Special Clear Hardener.

Install large cleanouts to adequately access the tank's interior.

[Copacabana]

Originally Posted by Terra Nova

Use WEST epoxy 105 resin with their 207 Special Clear Hardener.

Install large cleanouts to adequately access the tank's interior.

I would confirm with West if this product is food grade. It's important to use a food-grade coating inside tanks if you plan on drinking the water.