Author Topic: Holding tank maintainance  (Read 2758 times)

Odysseus

  • Old Salt
  • *****
  • Posts: 445
  • Karma: +2/-0
  • Bill and Linda
    • www.scanmar-odysseus.co.uk
  • Boat Model: Bavaria 38
  • Boat Year: 2006
Holding tank maintainance
« on: August 21 2019, 12:37 »
Another maintenance write up to make things easier for people.

I put hot water in loo and pump it untill hose is full to get the pipe hot. Then HCL , ( hydrochloric acid as per my engine elbo write up) down loo and pump enough through to stay in just the pipe, and leave for 3 hours.

This breaks down crud in pipe,

Then close seacock outlet and pump hot water and HCL through into holding  tank, leave for as long as you can manage. This removes crud for the lower part of the tank where the crud collects.

Tools for this are.

Socket extension pieces with a turning joint on end, this is to insert into top of the sealing cap as it's the way to break the seal on the cap, give it a wack untill it turns.

When removed you need a mirror and light go see into tank and assess what conditions are like.

I have a 3 feet lenght of flexible  plastic that  bends enough to get through the cap entrance, my  (stick) can go through pipe and seacock when contence is released .

On re assembly  put grease around thread of cap, this will make job easiest  next time.

Vinegar does not work folks, it's an old wife's tale, your choice.

Hope this helps
Odysseus
Bav 38
Odysseus

Salty

  • Old Salt
  • *****
  • Posts: 1216
  • Karma: +3/-1
  • Boat Model: Bavaria 36
  • Boat Year: 2002
Re: Holding tank maintainance
« Reply #1 on: August 21 2019, 20:06 »
Thanks for the information Bill, your holding tank interior is very clean which confirms that your system with hot water and HCL really does work.
I have a holding tank fitted, but not plumbed in yet, though it is on a long list of things to do over winter. Do you by any chance have a plumbing diagram that you could share for the tank connections?

Symphony

  • Old Salt
  • *****
  • Posts: 1106
  • Karma: +0/-0
  • Boat Model: Bavaria 33
  • Boat Year: 2015
Re: Holding tank maintainance
« Reply #2 on: August 22 2019, 00:27 »
You don't say what sort of holding tank you have. However, the plumbing should be obvious. If it is a gravity tank above the waterline it will have a 1 1/2" inlet at the top for the waste hose from the toilet, a 1 1/2 outlet at the bottom to go to the outlet seacock, a smaller diameter, probably 1" for the vent and an outlet on the top for the deck pump out.

This is the most common setup for a Bavaria, but some earlier (pre 2002 or so) had pumped systems with diverter valves so you could choose to either discharge direct overboard or send to the tank for later discharge using a pump.

Good information on the Tek Tanks website on the design of holding tanks and associated plumbing systems which might help you figure out how you should plumb yours.