Retro fitting a holding tank

[[2574]]

Our boat is ten years old and has no holding tank. Aside from the inevitable oncoming regulations as to the dumping of raw sewage overboard we've decided that we want to get on with fitting it now. It doesn't feel right using the heads anywhere near a beach!

I'm dreading the job! I'm after tips - someone must have done it before on here? Lee sanitation seem very helpful as to advice and parts but they are up on the canals - is there an equivalent south coast based organisation that anybody knows about?

rob

 

[pvb]

Tek Tanks also have a lot of experience and advice, and are in Hampshire. One tip would be to make it bigger than you think you need.

 

[martinriches]

I can recommend TEK tanks they made me a custom shaped tank and supplied all the fittings.Lots of info on the website. One thing you need to think about is how you want to empty it. If it is just through deck pump out it makes things simpler. I wanted the option of pumping out to sea as well [I think 3 miles offshore is OK]. I found the job fairly straightforward.Getting the flexible hose onto the fittings needed a hot air gun and washing up liquid.

Martin

 

[alandee]

You could try Vetus Marine. They provided all the parts I required when I fitted a Holding Tank etc. on a sale or return basis. Very helpfull chaps.

 

[Graham_Wright]

I made one in SS then learnt it was a bad choice. Ask Peggy ("Headmistress"- is she still around?). Very helpful. Buy her book as well;- "Getting rid of Boat Odors" (she is American!).

 

[Evadne]

I used Tek tanks when I fitted a holding tank to Evadne a few years ago. They make tanks to order or (like I did) you can look through their standard size tanks and decide if one of them will do. Much measurement and technical drawing, I didn't have to resort to a cardboard mock-up in the end. Their literature is free and helpful, you can also talk to them at the boat show.

They will put the fittings in the tank exactly where you specify: I had 3 holes, no inspection hatch. They are inlet, outlet and vent. The vent is 1-1/4" like the other two. To overcome SWMBO's worries the air vent had a charcoal filter. Peggy ("Headmistress") said this was unnecessary and she was right, of course. We now sail with no filter in place and no odours.

The precise set-up varies from boat to boat, but we have a Y-valve so the toilet discharges to the sea or the tank, using the same pump (our toilet is non standard with a seperate inlet and outlet pump, but that is irrelevant).

There is an electric pump (c/w macerator just in case /forums/images/graemlins/shocked.gif) that empties the tank into the sea. No deck fitting, we only use the tank in harbours and empty it once more than a mile or so from shore.

Don't do as I did and walk into the chandlers and buy whatever sanitation hose is on the shelf. Some fit onto seacock spigots better than others, even with hot water, hot air guns and wine bottles. I believe the Vetus stuff is better.

Good luck.

 

[jrt]

We used Vitesse (mostly Vetus bits) in the Walingford estate in Fareham. They were very helpful, and gave good advice. It fitted without any problem. /forums/images/graemlins/grin.gif

 

[alan006]

I agree that Vetus are very good. If you get one of their catalogues it has some very helpful diagrams explaining what is needed and where it goes.
Good luck.

 

[jimbaerselman]

Consider the height of your holding tank. If you have one above the waterline, it's very simple to plumb in. Loo always empties into the tank, and if the tank exit is open, goes straight into the sea. If the exit is closed, tank stores the stuff till the exit is opened. The only point to watch here is that if you're gravity emptying, the exit pipe must be short with no sharp bends, and preferably large diameter (2") to remove all possibility of blocking with calc deposits or 'stuff'. Conveniently, the vent acts as a syphon break.

My opinion, avoid any sort of filter in the vent. If, by accident, you overfill the tank, it will overflow through the vent. If the vent has a gauze or other potential block, it will block. Pumping the the loo will then pressurise the tank . . . which will burst.

Don't ask . . . OK, twice. You think I'd learn after the first episode!

 

[[2574]]

thanks all for your comments, very helpful - I'll approach the task with renewed vigour. And Jim - yes, once is a mistake, twice must be considered negligent!

rob