Where does the lime scale in the loo come from

Your concernes on limescale in the sea lavitory seem excessive to me. This is always going to build up. My solution was after 18 years of use the 1-1/2" waste pipe had a reduction in bore uniformly to about 1"This was remowed(almost needed a tackle to get it on deck) and the scale beaten out. dont worry WE piss over the side anyway its more conveinent. interesting discussion though and I learnt some chemistry.
 
Just to add as converts to Peggy's whtie vinegar treatment... We used it on out badly neglected RM69 in GL and basically recovered the installation to useable for the rest of this season. The outlet pipe when removed was pretty clear.
 
Re: Sea Salt

Thanks Dylan,

Very interesting, particular interest was the write up on Maldon Sea Salt, I wonder if the process to produce electricity sited further down stream ever had any effect on sales!
The Calcium Sulphate content for those who asked the original question is 0.55% so if you know the sea water to NaCl ratio you can work out the CaSO4 content of sea water.
I expect the stuff in the toilet pipe is very similar to the make up of kidney stones.

Trevor
 
Re: Sea Salt

Any suggestion what might be put into the loo of a boat on the hard with seacocks closed so that the deposited calcium carbonate can be dissolved out. The problem is that any acid will do not good to the bronze (probably brass) seacocks.

Something that would convert the calcium carbonate to a more soluble carbonate?

Obviously flush put with lots of water afterwards.
 
Re: Sea Salt

If it's on the hard and you're worried about acetic acid attacking bronze why not take them off and treat away from the metal.In fact if you take them off you can remove most of the deposits by bashing the pipes against a wall.
Personal op. I don't think that vinegar would have any significant effect on bronze or brass in the time it would take to clear the pipes.
 
Re: Sea Salt

If you're seacocks are brass, the least of your worries would be the vinegar affecting them by allowing the solution to sit in the pipe whilst the boat is on the hard.

Actually, you would have a problem filling the pipes up as soon as you close the seacock anyway. I suppose you could try nearly closing them and pumping to fill the pipe up slowly, but I would be more worried about electrolytic action in a 'brass' seacock than any build up in the pipe!
 
Re: Sea Salt

[ QUOTE ]
Any suggestion what might be put into the loo of a boat on the hard with seacocks closed so that the deposited calcium carbonate can be dissolved out. The problem is that any acid will do not good to the bronze (probably brass) seacocks.
Something that would convert the calcium carbonate to a more soluble carbonate?
Obviously flush put with lots of water afterwards.

[/ QUOTE ]

If you can get to the boat to put anything into the lines, you can get back to the boat within week or so to flush it out. It won't do the bronze any more harm out of the water than in it...it's days or even weeks that you're away while it's in...and you DO leave your seacocks closed while alway from the boat don't you?
 
Re: Sea Salt

Honest answer - no I dont. I live dangerously!

The boat is on the hard at the moment, and the layout (plus my laziness) makes it hard to get the pipes out. So I was wondering how to dissolve the carbonates (which I suspect are pretty thick in a 14 year old boat with what looks like original pipes) in situ. My memories of school chemistry suggests some acid (say citric or acetic) but I have visions of also dissolving the seacocks which would have to be left closed to keep the solution in the pipe doing its job..

So I then wondered about something alkaline - and my school chemistry gave up!
 
Re: Sea Salt

If you want to clear out the pipes quickly, run the 12% solution of hydrochloric acid through 'em with a bucket (NOT a metal bucket, plastic only) under the thru-hull to catch it (what you'll have to do with the bucketful of it is another problem), followed a lot of water to flush out what the acid breaks up but doesn't dissolve. You might have to do it a couple of times, but you can do it all in one trip to the boat.

Or, you can disconnect the discharge hose from the loo, pour white vinegar into the piping, and let it sit for a day or two...alo followed by a lot of water. Since vinegar is environmentally friendly, you won't need to catch it in a bucket when you open the seacock to drain it. You might have to do thi 2-3x times to completely clean out the pipes.

Neither method will damage your thru-hull or seacock.
 
After reading this thread have tried some (spanish) white vinegar on my heads and left overnight. Brilliant seized sea cock on the the aft head is now moveable again. I had resigned myself to taking the boat out of the water next year. Very happy bunny at the moment. Thanks Headmistress!
 
Not that it's got a lot to do with cleaning your toilet, but....

A friend, who used to serve as an engineer on nukey subs, reckoned that the bore of the heads pipes reduced by 75% during a cruise. Something to do with the excretion of calcium being much greater when the body is deprived of sunlight.
 
[ QUOTE ]
A friend, who used to serve as an engineer on nukey subs, reckoned that the bore of the heads pipes reduced by 75% during a cruise. Something to do with the excretion of calcium being much greater when the body is deprived of sunlight.

[/ QUOTE ]

A creative theory, but not the right one I'm afraid. It's the sea water, not the users, that contributes the calcium carbonates that build up in piping. As many people who are using each head on a sub, it's not surprising that the buildup would occur much faster than on recreational vessels that might be flushed only 100x in an entire season.

Vinegar is great stuff. Weekly applications will prevent buildup...mixed with a little baking soda, it'll unclog a drain.
 
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