Cleaning aluminium water tank with limited access.

[Jabs]

I need to clear an aluminium water tank. It has no access port and the water is causing some issues.

There is a mechanical gauge which gives access to a maybe 50mm hole.

The tank holds about 600 litres.

Access is not great.

The current suggestion is to use a pressure washer and pump the water out using a separate pump rather than through the plumbing.

Once the majority of the 'grot' is out, it probably needs disinfecting to kill bacteria and delay future growth, together with flushing out the pipework

I would usually use a strong solution of bleach and absolutely slosh it all over the inside of the tank.

I assume it would be unwise to use strong bleach in ally tanks?

Would antibacterial surface cleaner do the job?

Any bright ideas for carrying out the job?

Any advice greatly received.

Thanks.

Tony

 

[island163]

Sounds like an Island Packet water tank. I've heard of people using a wet and dry vacuum cleaner to suck up water and aluminium chloride crystals from the bottom of the tank. On an Island Packet baffles in the tank prevent you from reaching all of the tank so it's hard to reach all of the crystals, perhaps a blast with a pressure washer would help swirl them around so you could then pick more stuff up.

Disinfecting the tank needs to be done with something that does not react with aluminium, bleach or any cleaner with a lot of chlorine in it is probably a really bad idea unless you don't mind replacing the tank when it starts leaking. On Island Packets people seem to use either a strong solution of hydrogen peroxide or a product called Purogene. However on my boat we don't clean the tank but we do clean the pipes as that is where the smell seems to come from. We also filter incoming water to remove chlorine and use a seagull filter at the sink to filter water we are going to drink.

 

[SandgroperWA]

Having cut an access port in an aluminium tank in my last boat to try to repair a leek I was amazed at the mould like growth in it. I will never drink out of an Ali tank again, filtered or not. If just used for washing can you cut an inspection on top of it and then silicon on and rivet a cover plate later? There probably won't be much pressure on it on less on an angle such as in a listing yacht. Good luck.

 

[Floyd Raser]

Having cut an access port in an aluminium tank in my last boat to try to repair a leek I was amazed at the mould like growth in it. I will never drink out of an Ali tank again, filtered or not.

Nor me. Google "dementia and aluminium". The aluminium wouldn't bother me, but the growth/salts would.

 

[EdWingfield]

Jabs, as you cannot get access to physically de-grunge the tank with elbow grease, the best you can do is to 'super-chlorinate'. And not just the tank, but all the plumbing. Buy some cheap unscented supermarket bleach. Call the company on the phone number on the label. Ask for technical advice. You will be connected to a guy in a in a white coat. Tell 'em you want to super-chlorinate a potable water tank in a yacht.

You will be asked volume? Which I think you know. You will be told how much product to add for appropriate concentration and time (usually 24 hrs)

Don't forget to run the super-chlorinated water to stand in all the pipework.

Thereafter you should dose the water at every fill.

I'd expect them to advise you for 50 parts per million (ppm) or mg/l to super-chlorinate for 24hrs, then discharge it into the sea. (don't worry, the Cl will breathe off to air)
and to dose thereafter give it 2 ppm.

Good luck Skipper.

 

[rogerthebodger]

Have you considered using a high pressure washer through the 50mm hole.

You may get most clean but without an access hatch that you can get you head through you would not be able to inspect it properly.