Blocked toilet hose

Seems not to cause any damage to Jabscos, hose or seacocks. The only report we have every heard of on these forums of a problem with hydrochloric is your report, today, of soaking a Y valve of unknown material for an unknown length of time in an unknown Turkish chemical.

If there was a problem with hydrochloric we would probably have heard of problems long before now.

The effect of acids on plastics is to a great extend dependant on the concentration of the acid. If you go back to the beginning of this thread I have suggested suitable concentrations.

Citric acid has not been used widely to clean these toilets as far as I know, so you will need to see how it goes. Citric acid is not necessarily safer just because it is present in lemonade. Good luck and let us know how you get on!
 
David,

How do we know that these treatments are having an effect - e.g. my forward toilet blocked in 2007, 12 years after the boat was launched. The aft toilet blocked in 2008, 13 years after launch. I have now renewed both and, all things being equal, I could guess that it will likely be another 10 years or so before another blockage, even without Hcl or whatever.

Or do you remove your pipes for a look every now and then?

I think you will get my drift

Regds

Richard
 
Hi Richard, Yes, I remove the seacock end when I service the seacocks, when we are out of the water, so I can see the amount of scale at the bottom and how the metal looks. When I service the Jabsco I generally remove the soil hose from that, and can see what it's like inside. Occasionally someone blocks a loo and I get another chance to inspect the pipe. I don't have any visible scale at all -- though obviously I can't see right along the length! In my father's case he lived aboard for 25 years and they had problems early on to start with and then never had problems after he started using hydrochloric. His toilets were Simpson Lawrence SL401s which had very fussy bits and stainless springs. I'd need Madame Arcaty to get any further detail on that, tho' /forums/images/graemlins/wink.gif

As for your 12 and 13 years without descaling....you haven't been a liveaboard yacht for all of that time, I believe? My suggestion is to descale once a week every week you occupy the yacht. So for ordinary weekend and holiday users many won't need to descale more than five or six times a year.

Sometimes I forget (or to be honest, can't be bothered) to descale for a few weeks and when that happens I tend to get a lot of gritty stuff - presumably scale - falling back down the pipe (the pipes go up in a long loop well over the waterline) and into the pump, It feels gritty. You can pump it through vigorously or add some neat HCl in the pan and work it through the pump - which clears the grit. So clearly the grit dissolved in acid which supports the theory that it is scale. In other words, the acid does not just dissolve the scale, it tends to dislodge it.

If you ask around others -- e.g. Englander, and many others on this forum -- you will find that many if not most long-term liveaboards in the Med use hydrochloric. If you live aboard and don't use hydrochloric, depending on how much you use the toilets and how thoroughly you flush the pee through, you might have to clear your pipes between every two to four years but at the end you will be getting constant blockages as solids are hard to get through.

One other factor might be where you are cruising. The Med might have a higher calcium content than the ocean and open sea. It certainly has a higher salt content.
 
Again Thanks for all the tips I am getting from this least favourite job. It seems while traveling to turkey going to hardware shops that speak little english I have been looking only at descaling fluids in the belief that they are all made up from the same composition. after doing a bit of reading on the web it seems that descalers come in a variety of ingredients from citric, sulphuric, phosphonic,biodegradeable and non hazadous types and many more. The descaler that I use in turkey is called coz and is widely used on boats for a variety of purposes.

When I get back to Turkey I shall have to take a closer look and see exactly what it is made of. If hydrachloric acid is the time honooured descaler I shall have to see if I can buy it over the counter and find a safe place to keep it. (Children on board) You cant guess how many times I have blamed the kids for blocking the toilets hence my interest in this messy horrible job.
 
Some points worth bearing in mind about the various calcite deposits in loo pipes.

It's much worse in the Med, with two possible causes:
1. Higher salinity
2. Higher temperatures causing evaporation internally where the pipes don't remain immersed in 'stuff'.

Thus, If you don't flush the pipes in any acids, assuming six months full time seasonal use each year, you'll need to clear the pipes mechanically every 3 to 6 years in UK waters, and every 2 years in Med waters. Any longer gaps, and you risk occasional blockages. Of course, 6 week a year users can multiply these gaps by 4.

If your syphon break is working properly, or if you're filling a high level holding tank, the downhill side from the high point of your exit loop is going to empty quickly. This causes increased evaporation, and thus higher deposits. typically, my upside of the loop will suffer minor encrustation, while the downside has two or three times the thickness.

Clearing with acid does not work effectively on downsides of loops, since (unless you do some nifty work with the outlet sea cock or block the syphon break) the acid won't have time to do it's stuff. And if the acid does have time to do it's stuff by judicious blocking, quantities of carbon di-backside will be produced - and has to go somwhere . . . you'll then get a foaming overflow from a burst pipe, or maybe a popped joint.

Don't ask.

From all this experimentation, I concluded (perhaps wrongly) that flushing regularly with acid couldn't be relied on either. So my answer was to make mechanical removal and replacement of the pipes easy by adding joints at crucial places in the pipes to minimise threading problems, and carrying spare pipe for the bits that get busted occasionally through my ham-fisted removal techniques . . . then one or two hours work per loo every two seasons wasn't too onerous.

Mind you, with 36 boats that's full time work for some poor fellow for a couple of weeks . . . but then charter fleets have a big incentive to find easy solutions which don't disturb the clients.
 
I've done a bit of research online and haven't found any marine toilet Y valves that say they are made of Nylon. Some don't state material but those that do don't show Nylon. That's not to say that yours isn't Nylon, of course. Nylon is non-resistant to most weak acids and would obviously be a poor choice for any components in a marine or other toilet since chemicals, often acid, inevitably have be to be used (vinegar is the favoured choice in the USA though I don't believe it does much and over here is very expensive, for food use). I have also searched for marine toilet spare parts and Nylon and the only toilet that seems to have any Nylon component is a Raritan, and that component is a nylon washer that appears to be a shim. It isn't obvious whether that is immersed in the sewage, either. There do not appear to be any Jabsco parts that are stated as Nylon. When I service my Jabscos, which are subjected to an acid treatment every week -- 52/52 -- I never see any kind of deterioration of the plastic and even the valves are usually in good condition, visually. Back in the 1970s and 80s when I used to service my father's SL401s, there was a stainless spring that used to corrode but I wouldn't be sure whether that was due to the acid we used. I think it was a well-known defect of that particular design. None of the plastic parts ever suffered.

So I think it is safe to assume that Jabscos are fine with HCl, as is toilet hose and sea cocks provided they are left open to the sea to allow the concentration of acid to fall quite quickly. I have heard of people closing the outlet sea cock for descaling, and pumping through a partly-closed cock until the acid should have reached the cock then close the cock. Sounds good in theory (and I tried it for a while) but it leaves acid on the metal for hours and in any case it does not seem necessary. As the weekly acid passes along the pipe it dissolves and dislodges scale.
 
[ QUOTE ]

It's much worse in the Med, with two possible causes:
1. Higher salinity
2. Higher temperatures causing evaporation internally where the pipes don't remain immersed in 'stuff'.

[/ QUOTE ] The scale arises from the ammonia formed in stale urine causing calcium salts to precipitate from the seawater. It isn't common salt, but calcium. If there was evaporation in the toilet pipe it would condense and the net effect would be zero as it is closed to the atmosphere. It is possible that the calcium salts are present in greater concentrations in the Med, which might contribute to the problem and perhaps we receive more reports from the Med because there are more retirees and longer-term cruisers and liveaboards in the Med than in many other regions. The more you use the toilet (days per annum) the bigger the problem unless you are fastidious about a long pump-out.

[ QUOTE ]
If your syphon break is working properly, or if you're filling a high level holding tank, the downhill side from the high point of your exit loop is going to empty quickly. This causes increased evaporation, and thus higher deposits. typically, my upside of the loop will suffer minor encrustation, while the downside has two or three times the thickness.

[/ QUOTE ] If there is encrustation then the soil has precipitated out the calcium. It can only do that if it is in contact. If the soil is in contact, then so will the acid be. The acid goes where the soil goes. The parts that are more heavily encrusted are likely to have been in contact for longer, as they will be with the acid.

[ QUOTE ]
Clearing with acid does not work effectively on downsides of loops, since (unless you do some nifty work with the outlet sea cock or block the syphon break) the acid won't have time to do it's stuff.

[/ QUOTE ]I think it would be unwise to block the seacock if metal. If the cock is open to the sea then the acid concentration will diffuse quite quickly. Wherever there is encrustation the acid can be expected to work. I don't see how the anti-syphon break is relevant? Nothing should come out of it. The acid travelling along the pipe dissolves and dislodges scale.

This is what most people seem to do and it is the norm in domestic toilets around the Mediterranean basin -- which is why all the supermarkets sell HCl ! Pulling out the soil pipes and banging on the dockside is not something I choose to design-in as part of my maintenance schedule when I can pour acid down instead.
 
The point about scale on the down side of the loop is well made. It is very difficult to ensure that HCl remains there, whereas on the upside it is quite easy. At end of last season all the hoses in the immediate area of the toilet were completely clean, thanks to regular treatment with acid. The downside of the hose and the seacock itself were encrusted.

IMG_0002.jpg


I wouldn't expect any significant reaction between seacock bronze and dilute HCl and mine are certainly not affected after several years of its use. Although looking at the photo, acid and metal probably never come into contact!
 
[ QUOTE ]
The downside of the hose and the seacock itself were encrusted........ Although looking at the photo, acid and metal probably never come into contact!

[/ QUOTE ]Mine were clear last time we were out of the water (18 months ago) so maybe this suggests that I use more acid than you do? Or maybe there are those on your yacht who are not such vigorous pumpers -- or do you use one loo most of the time -- we split equally between two - his and hers! Anyway, more acid should do the trick and make sure that it is hot, not cold. Cold weak acid doesn't do a lot.

When you think about what's happening, the first part of of the path - toilet and first half of the pipe - are neutralising the acid as it passes along. So by the time it gets to the downhill section and the seacock much of it has already been used up in dissolving earlier scale.

What is your descaling regime so we can compare concentrations and techniques?
 
[ QUOTE ]
. Although looking at the photo, acid and metal probably never come into contact!

[/ QUOTE ]

As a liverboard with kids the picture show exactly where the blockage happens most of the time. Its exactly how I clear it as well. After removing any loses bits that have fallen down the pipe I pour a descaler into the opening with a throw away towel to soak up the foaming over flow. I open the valve slighty to flush away any debris and to get rid of any descaler left. I bang and bend the dpwnside pipe as I have seen more than a few people do until its clear. Replace everything and give the system a good flush, Normally its the downside that is blocked. The upside to the vented loop is normally always clear although from time to time this needs to be replaced or cleaned, from that point onwards I try to make sure the toilet is properly flushed but as a liverboard in the med with kids and all there friends this doesn't always happen and am slightly jealouse hearing people say they dont have to do this job very often sometimes quoting years.

I have replaced the pipes this year, but in Turkey they cost a fortune especially jabsco sanitary pipes

Its obviouse from the replies that everyone has there own ideas. I am laughing to my self thinking of everyone having a drink in a bar having this discussion. Tis a blessing we are not all surgeons
 
Only one loo on a Sadler 34 - and that's a pretty tight squeeze!

I can't claim to dose with HCl every week, every month would be more like. I do it cold, with undiluted HCl as it comes from the supermarket. Put a litre in normally, listen for the bubbling, slowly pump to empty the bowl, leave it for 10 minutes then flush through. I have tried subsequently to part close the seacock to trap HCl in there, not entirely successful I expect. Fortunately it has never been a major problem, so I doubt if I shall make any greater attempts to clear the downstream side. Banging the hose with a mallet seems to work pretty well, clean the seacock at the end of the season.
 
The hose to the left was the upside, attached to a vented loop. The hose to the right was attached to the downside of the same loop. I have a matching picture of the loop exits. No acid flushing has been used. This is after three years of 6 months occupancy a year in the Med, starting clean. The downside led to a sea cock.

The previous six years, spent in Atlantic waters, produced little encrustation.

GRapaz5.jpg


You state that deposits come from the soaked side, not the downside. I conclude that the conditions on your boat differ radically from the conditions on this boat. Or perhaps we create different end products?

When I referred to salinity, I used the general term referring to all the dissolved salts found in seawater. I don't know why you assumed I was only referring to sodium chloride, a rather narrow definition of salinity.

To clear depostis, I can't imagine how to arrange the acid to remain in contact on the downside of the loop. My imagination ran dry after bursting the hose, since I was rather slow to open the seacock when the hissing sound started. You see, the vented loop lets air in, but not out. And, in normal use, ensures the downside is empty.

It's possible, of course, that a regular (fortnightly?) flush with acid might be a preventative. Just a ten minute job each boat, 12 times a year, adds up 2 hours a boat a year. That's the same as beating out the pipes once every two years, give or take an inch. However, has anyone conducted an endurance test to check that acid flushing really does work in the Med? Giving you, at least, say, 5 years freedom from encrustation? Or are we just talking theory here?
 
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