Black tank sensor.

[Driver]

Hello,

I have two aluminium black water tanks with senders and analogue guages. I bought the boat last year and the guages always showed zero although there was waste in the tanks. Testing showed it was the senders. The boat had been little used previously. After a while one of the guages started to work and is now fully functional after a "few miserably small at high price" cans of black tank cleaner had been added. The other has been less cooperative and, you guessed it, its the one that can only be accessed by a young, thin person with long arms and much determination. I fail on two of the requirements. The conveniently screwed in sender is so tight that it will likely break before it comes out.

Does anybody know of something that may work, or a powerful black tank cleaner, safe with aluminium and the pumping system and available in the south of France, in say 5 litre cans?

 

[TrondS]

I'm using Gobius black water tank sensor. Mounted externally on the aluminium tank.
On my tank 3 sensors are fitted at about 1/4, 2/4, and 3/4 level. Never had any issues.

 

[Portofino]

Fill the tank 1/2 full add 5 L of brick cleaner and go out in big seas flying off waves .Soon loosens it .

 

[Driver]

Gobius sounds a solution if all else fails but I am trying to keep my existing guage.

Does brick cleaner not attack aluminium and rubber?

 

[Portofino]

Gobius sounds a solution if all else fails but I am trying to keep my existing guage.

Does brick cleaner not attack aluminium and rubber?

It dissolves the accretion of calcified crap on the sender stalk so the float can move .
The violent action of 1/2 tank sloshing about in rough seas does the rest , frees up the float .It’s 5 L into 1/2 a tank .
Not permanent, just that day when its rough out .Then empty it and dilute with sea water or what ever .

Yes neat HCL dissolves Al in your school boy chemistry lesson test tube .But it’s not neat and or left long enough.Aside the tank sides might be coated in crud anyhow .Rubber is inert to acids .