Retro fitting a holding tank

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IanH

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This may seem a strange question but here goes. We do not yet have a boat but are on the lookout and think that a Westerly Konsort will probably be the very thing for us, however, MrsH is not at all keen on the idea of a sea toilet discharging overboard. She has also raised the eminently practical question of what does one do when in a marina?

So the question is, is it possible to fit a holding tank somewhere on board (?forward under the vberth) and have some form of valve arrangement whereby the user can switch between holding tank and discharge overboard? Maybe I should have asked not whether it is possible, because anything is possible but how difficult it would be to achieve this? I am thinking that a holding tank may only be quite small but only for occasional use whilst in marinas or at anchor.

Any help/advice gratefully received.

IanH
 
I Have a Westerly Discus and the previous owner fitted a small holding tank in the cupboard above/behind the heads. All of the waste goes to the tank, then a manual pump (same as heads pump as we have a lavac) pumps overboard. A deck vacuum fitting is also fitted.

With two of us onboard it lasts about two days before needing to be pumped out, while on passage we normally pump out once per day to keep the weight down (but to be honest we've not really noticed any problems).

I sometimes wonder about changing the plumbing to put in a Y valve for direct overboard discharge, but the current set up works well and has the virtue of simplicity.
 
We're about to fit a holding tank to a Westerly Seahawk and have found Lee Sanitation very helpful. I would have attached a direct link to their website but the new forum set-up is not as helpful as the old one for that. The address is http://www.leesan.com/

You'll have various decisions to make, including the option of a deck pump out facility. I suspect that in perhaps 10 years time some marinas will start to prevent the use of heads without this arrangement.

Good luck.
 
Almost certainly somebody else has done it. The Westerly Owners Association is your first port of call.

In principle a gravity tank is the better option. That is a tank mounted above the water line and emptied through gravity. However, not all boats have room and size can be limited. It is arguably the most common arrangement on new production boats. I have retrofitted two - one to an old wooden boat and the other to a Bavaria.

Your suggestion of putting it in the forecabin under a berth is common, but this needs to be the pumped type which is much more complicated and costly.

In addition to the Lee Sanitation site suggest you look at www.tektanks.com they make custom tanks and have a lot of information on the site of different systems and layouts.
 
Put one in the forecabin of a Prout and its one of those rare projects that when you look back on it and see how it worked, you would do exactly the same way again. Got it right for a change.

The tank needs to be a hard one - bag tanks eventually leak and after one memorable Sunsail charter with a leaky holding tank I would nevere ever risk that.

Simplest method is to route everything through the tank so avoiding divert valves which can easily be a blockage site.

Had a made to measure tank with the outlet to the sea being a pipe welded into the tank top but finishing an inch above the bottom. From the tank top it then went to a diaphragm pump and the sea cock - since the tank was above the water line, the first few pumps started a syphon and then I could just leave the tank to empty itself.

Tank ventilation matters - you need a decent sized ventialtion outlet prefereably with a filter on it.

Final tip - do what they do in the med flotillas. Faeces down the toilet but toilet paper, san towels etc into a bin to be emptied daily. It doesnt smell and it makes sure that your tank will never block.
 
Before buying any Westerly join the Westerly Owners Association who will advise you during your search and help you interpret survey reports. You might find a good private sale there as well. They welcome non-owners and the association is large, helfpul and informed.

Tek Tanks will have made tanks for the Konsort if anyone has and they will give you advice on where people have put them.

I don't go along with your wife's aversion to discharging overboard. The planet has evolved to deal with human and other animal waste. There are plenty of creatures from microscopic to big that clean up. That's how nature works. All sewage works have overflows into rivers and the sea. The population today is far to big to allow direct discharge of raw sewage but the discharge from a few yachts in most places where there is a tide is not a problem for the environment. The dishwater and shower water (grey water) and bilge water is more environmentally unfriendly than sewage.

In marinas most people use the facilities for solids but most people will flush pee. In anchorages where there are bathers, or by beaches, no thoughtful person would discharge solids. If you are only at the anchorage for a few hours you can pump the solid into the pipework until you leave to go to sea. Pee into a bottle is what I used to do when on the hard without a tank, or the wife can use a pot. Pee is sterile and no problem for twelve or more hours.

Instead of a holding tank a cheaper option is to buy a Porta Potti but they are quite bulky to store when not in use. If you do that keep it clean and fresh so you would store it in its box in a wardrobe needs a good hose down inside and out. I have friends who do that and it works for them. It would not work for me.

The Konsort is a nice cruising yacht. Good choice and you should get a good deal now.
 
I got a Portapotti for those awkward times. After a while, found we were using it most of the time on the boat. Have now removed horrible smelly pump-out toilet and moved nice clean fresh Portapotti into place permanently. I take all waste ashore, but you could empty overboard while at sea if you wanted, or needed to. Big tip with Portapottis is to use the pink flush additive and the blue waste additive in the correct quantities (don't use the green waste additive)

Enjoy your new boat! Neil
 
Thanks for the advice

Dear All,

thanks very much for the advice and tips. Yes we will be joining the WOA before buying.

Manuel, I agree that the squeamishness around discharging overboard is not rational given a fuller understanding but hey we all have something that makes us feel a bit icky and I think that I ought to at least investigate how these feelings may be accommodated.

We previously (six years ago now) owned a motorboat on the Thames which had a portapotti. Wasn't such a chore to look after or empty to think about it so that may also be an option if Barb can't get over her issue with discharge at sea.

Thanks for the links to leesan, if that is the way we go, when we finally find and acquire a boat, then I will certainly be intouch with them. Actually, thinking about it I'll give them a call now to get an idea of cost, all part of the budgeting process.

Thanks again

Ian
 
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I have a Westerly Konsort and retro fitted a holding tank to mine....

The tank (42 litre plastic tank made by Vetus) is fitted in the port side locker under the V-berth (which is where the seacocks are). It takes about 3 to 4 days for two adults to fill it. I built a slatted wooden shelf to hold it clear of everything in the locker.

My first installation used a diverter valve so I could switch between sea and tank. The valve failed so I now go straight to tank. All paper is binned not flushed.

The tank system uses a smallish whale bilge pump to suck out the tank to the original sea cock. I do this once out in deep water and away from swimming beaches.

I don't yet have a system for getting waste ashore in a marina yet. Routing a big pipe back into the heads to get to the deck looks tricky at the moment...
 
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