Holding tank

[dancrane]

That's most encouraging Stu, although the rarity of reports of "no trouble ever", lead me to think there must be something clever or fortunate in your boat's layout or components, which has evaded the design or opportunities for layout, in most other people's boats.

Hence I still wonder what the ideal is - in terms of pipe length/diameters/angles, proximity to tanks and skin fittings, heights above the waterline, types of pumps and valves etc, etc, etc.

I tend to be dissatisfied with most yachts' interiors, so I wouldn't be opposed to completely re-siting the bathroom when I finally have a yacht to mess about with. It'd be beneficial to learn from so many people's repellent accounts of maintenance and mistakes, and of kit that wasn't up to the job. Isn't there already some sort of lavatory-bible, listing the best ways to make it all fit together flawlessly - and which corners the designer or retro-fitter may regret cutting?

 

[Robin]

We have 2 Jabsco manual loos and 2 holding tanks. Since buying our boat I have replaced both original manual pumps with twist 'n lock ones, easier than strip and refurbish and not much more money. Both our holding tanks are semi gravity drain so are left open to sea overnight. NO paper goes through the loos ever, we have large plastic lidded coffee containers into which all paper goes, these are lined with black odour blocking and bio degradable dog -poop collecting bags for easy hygienic disposal. Not had a paper blockage even on boats without holding tanks but wish to avoid that risk, especially now we are in a locked basin., We have, hosever had weed block one loo's water intake, the hot weather seems to have encouraged slime weed growth. The weed blockage was cured by applying the dinghy pump to the intake pipe at the top of the hand pump

 

[davidaprice]

We've a slightly odd setup: when we bought the boat second-hand the pump-out outlet on the top of the tank clearly didn't have a dip tube and hence didn't work. The boatyard fixed it by plugging that outlet and adding a T-joint in the hose down from the tank to the sea-discharge (attached above its sea-cock), and a hose from that T-joint to the pump-out deck fitting. (So pumping out also drains the tank through the outlet in its bottom). We use rapid-dissolving toilet paper and either pump-out (common and always free here in Finland) or offshore we open the sea-cock to discharge to the sea. No problems so far, in many years of use, with pretty much zero maintenance.

 

[Graham_Wright]

A rather unpleasant drift - the problems (indeed many heads problems) seem to result from the usage of non "passed through the body" items. I have had my fair share although generally with sea cadets on board who have to clear the consequences of not following the rules.

Anybody imposed the rule "wash don't wipe"?

I tried this on our recent charter in the Caribbean as an alternative to binning the toilet paper. It wasn't nice but I became used to it.

In a constant 30° temperature, we were naked anyway. It might not be the same in British waters.

 

[BelleSerene]

I dont understand this loo blockage thing, I lube the Jabsco regularly, change the flap valve when it starts to back flow (contrary to popular belief the joker valve DOESNT seal) We use a minimum of six pumps and the paper does go down the loo. It has been in the boat from new, we have had it 9 years and the only upgrade was the twist and lock pump, now that is a JOKE!

I'm with Stu. Joker valves are cheap and easy to replace, and reward you with a loo that doesn’t backfill. Life need not be so austere as to insist that we bag our used loo paper.

Anyway, the one time I had a blockage similar to the OP's (it was due to a large excess of loo paper following an incidence of diarrhoea) I fixed it fairly easily with a pump-out. But unlike the posters above, this pump-out (it was at Shepard’s Wharf in Cowes) had an rubber fitting that jammed airtight into the deck fitting, not a long tube to insert into the tank. I put a surgical glove on, and with the machine sucking up through the top of the tank I held the gloved hand (use a rubber glove because the suction is considerable) sporadically over the flat breather valve on the side deck. I left the seacock beneath the holding tank open. This created a strong suction UP the seacock - the opposite direction to the way the blockage had formed - on and off as I covered and uncovered the vent with my rubber-gloved palm. A big pop, followed by release of the offending paper into the water (sorry). Then suck out as normal.

That was once in twelve years' family use of the heads.

 

[derekgillard]

Yes another holding tank question.. Please

My Bav 30 has the gravity type holding tank eg open the sea cock and if discharges, (or should do :'()

ALL my crew are under strict instructions that nothing goes down the toilet unless it's human waste we have a paper bin by the loo. So either my problem is that someone forgot and put paper down it OR calcium build up.

Ours blocked yesterday the standard trick of taping up the breather cleared it, then it blocked again same day and nothing will clear it, the level is now above the inspection hatch so can't get in there

I can only assume my other option is to get the marina to pump it out. Has anyone experience of this if so if I leave the sea cock open while they pump it out is there a chance that it can suck up or free whatever is causing the blockage? If not guess i will try to get my hand in via the inspection hatch OR remove the outlet pipe from the base of the tank once emptied.

Any other bright ideas will be appreciated. I would say i cleaned the tank last year and it's worked fine for 10 months.

Finally if and when i do clear it I've heard white vinegar helps to keep the Calcium away anyone tried this?

Thanks as always, this post is also on the Bavaria Info site.

Derek
Yacht Sa Punta.

FEEDBACK
I cleared it by using an oil pump extractor to pump out the contents and dispose of , then used a sink plunger to clear the blockage via the tank inspection cover.
It was packed with calcium no paper! once cleared a jet blast of fresh water into the tank broke down the calcium.
I think a blast of fresh water every 3-6 months is now part of the maintenance schedule
Thanks for all the advice

 

[dancrane]

If calcium build-up is a significant problem for boat lavatory systems, couldn't it be solved by use of a patent descaler like this?

 

[BelleSerene]

If calcium build-up is a significant problem for boat lavatory systems, couldn't it be solved by use of a patent descaler like this?

Vyv Cox has previously recommended hydrochloride acid for this purpose. Or I’m aware industrial white vinegar will do the job. Does any chemist around here know a suitable concentration to use? Assuming the usual AWB setup of a marine Jabsco loo, plastic holding tank, synthetic piping and brass or whatever they are seacocks? And presumably you’d leave it to sit in the tank for 5-10 minutes before releasing the seacock?

Yes, of course you want to be at sea when you do this. I note Vyv has advised:

The good thing about using hydrochloric acid for this purpose is that its reaction products are mostly calcium chloride, water and carbon dioxide, none of which could be called harmful to the environment. Not too sure about the sulphamic acid...

However, the main point is that using these products until they have reacted and then releasing them is not particularly harmful.
​

 

[vyv_cox]

Vyv Cox has previously recommended hydrochloride acid for this purpose. Or I’m aware industrial white vinegar will do the job. Does any chemist around here know a suitable concentration to use? Assuming the usual AWB setup of a marine Jabsco loo, plastic holding tank, synthetic piping and brass or whatever they are seacocks? And presumably you’d leave it to sit in the tank for 5-10 minutes before releasing the seacock?

Yes, of course you want to be at sea when you do this. I note Vyv has advised:

The good thing about using hydrochloric acid for this purpose is that its reaction products are mostly calcium chloride, water and carbon dioxide, none of which could be called harmful to the environment. Not too sure about the sulphamic acid...

However, the main point is that using these products until they have reacted and then releasing them is not particularly harmful.
​

Hydrochloric acid is well worth adding to the toilet, where amounts of carbonate salts (actually mostly magnesium with some others including calcium) are relatively small. It will take a very large volume indeed to clear a holding tank. Far better to use water jetting and some mechanical method such as wooden sticks and banging the outside of the tank. I shall be doing mine in the next couple of days, having learned over years that this is the best way.

Hydrochloric acid sold in supermarkets throughout Europe for drain clearing is about 6% w/w but mabe shown as anything between 20 and 30%, which is the dilution rate of the conc acid, itself being the HCl gas dissolved in water at a maximum concentration of 37%.

 

[vyv_cox]

Spurred into action by this thread I have done the job a day or two early. We had known for some time that there was a delay between flushing and the tank emptying, which can be heard. This turned out to be substantial blockage of the short exit hose and seacock, cleared using a length of aluminium tube that I keep for the job.

Otherwise the tank was fairly well coated with scale a couple of millimetres thick. Much of this was removed by water hosing but the rest needed a plastic scraper. Once the hose has been used there is no sewage in the tank, so I have no qualms about putting my arm inside to scrape walls and floor.

The tank holds 50 litres, although it has very rarely been full. The whole job took less than half an hour and will last at least another season.

 

[cdrmike43]

Had the same problem on a nearly new Bav38. Discharge valve has a right angle bend which does not help but opening and closing valve several times worked at first. Tried to blow out using dinghy pump on the vent but just started to inflate tank!!!
Final solution was to insert bent coat hook from the dinghy and that worked but once empty, cleaning out the tank was essential to prevent further trouble. OK now for 10 years.

 

[Heckler]

That's most encouraging Stu, although the rarity of reports of "no trouble ever", lead me to think there must be something clever or fortunate in your boat's layout or components, which has evaded the design or opportunities for layout, in most other people's boats.

Hence I still wonder what the ideal is - in terms of pipe length/diameters/angles, proximity to tanks and skin fittings, heights above the waterline, types of pumps and valves etc, etc, etc.

I tend to be dissatisfied with most yachts' interiors, so I wouldn't be opposed to completely re-siting the bathroom when I finally have a yacht to mess about with. It'd be beneficial to learn from so many people's repellent accounts of maintenance and mistakes, and of kit that wasn't up to the job. Isn't there already some sort of lavatory-bible, listing the best ways to make it all fit together flawlessly - and which corners the designer or retro-fitter may regret cutting?

I think the prob is actually people!
They dont understand the basics of how the Jabsco works and dont like getting low down and dirty in the poo!
No 1 rule, pump a lot, it helps stop the build up of salts.
No 2 rule, when it gets stiff and squeaky, lube it. I actually shut the seacocks and undo the plastic "nut" under the pump handle. The whole piston etc comes out, I then grease it and the stem as well so that the seal on the top doesnt bind.
No 3 rule, the joker valve doesnt stop the back flow, its the flap valve at the bottom of the piston that should do that when all else fails. They get indented by the seat it sits on and need replacing every six months or so.
No 4 rule, interim lubes with some cooking oil dropped in the bowl and pumped through.
No 5 rule, pump the cooking oil out with the main outlet valve half shut, it gets some oil on the ball and then a few open and closes spreads the oil around the valve seat.
So no probs for me and yes we do pump paper through, the cheapest Lidl type paper disintegrates easily.
There arent any syphon breaks and the outlet is just below the water line. When it does backflow it doesnt overflow the bowl.
Works for us.
PS As Ive said before, the second heads I removed and put a Port Potti in there, Seriously good bit of tack, lasts three days for us two and keeps us legal when a holding tank is mandatory.

 

[pmagowan]

Our old boat didn't have a holding tank so there was no problem. The only problems I have had is when someone put a wet wipe down!! That did for the old loo and the replacment jabsco worked fine for years without any significant maintainance. The new boat has a holding tank but we generally don't use it since we are either somewhere with a good tidal flow or in a marina with facilities. We use cheap toilet paper and put it down the loo without any problem. I do put a bit of olive oil down there from time to time. I might replace all the pipes since it is a new-to-me boat and I like to know what I am dealing with but perhaps that is a job best left until there is a problem? Jabsco toilets are so cheap it isn't really an issue if there is a problem. Buy a new one and then you have spares!

 

[BelleSerene]

No 5 rule, pump the cooking oil out with the main outlet valve half shut, it gets some oil on the ball and then a few open and closes spreads the oil around the valve seat.

Stu - meaning the holding tank seacock? I don’t think it have a controllable valve before that.

 

[degsyuk]

Hi we have a Bav 30 and our holding tank used to block on a regular basis and spoiled many a trip. The following worked for me and has permanently resolved the problem. BTW, we always put toilet paper (single ply is best) through the toilet.

1. Replace the 90 degree elbow pipe that is located just before the seacock with a straight one (a right angle in an outlet pipe is always going to cause problems at some point).

2. Install either an electric or manual pump between the holding tank and the seacock. We used a Whale Mk5 manual sanitation pump .

3. Install a second ball valve (sea cock) between the holding tank and the pump. This allows the pump to be isolated from the holding tank for servicing.

It's a bit fiddly, but we installed the pump, extra seacock and the pipework in the cabinet under the sink in the heads. Once installed we were able to evacuate the blocked holding tank (in an appropriate location) without issue.

Hope this helps.

 

[Heckler]

Stu - meaning the holding tank seacock? I don’t think it have a controllable valve before that.

aNot the holding tank, we dont have one, its the thru hull one I am referring to. My holdng tank is the Porta Potti.