Toilet limescale reduction/removal

[Peter]

Sure this is a subject covered many time but searchs give poor results. My question is how to remove/reduce limescale in toilet outlet pipes having just removed and beaten them to death to remove said product.
I've heard vinegear is one answear, but how much, how often how to apply, how long to leave etc.
Another product I've read about is dilute hydrochloric acid (brick cleaner), this seems slightly more aggressive, again my question if anyone has used it, how much to add, how often, any effect on toilet parts (jabsco toilet) etc

Look forward to any replies

 

[Mister E]

We use white vinegar as a spay around the bowl when the boat is not being used. We got the boat with limescale in the bottom of the bowl after a few months this was gone.
Just a slight smell when first entering the toilet but soon vents away.

 

[macd]

If you don't have a holding tank, Peter, the easiest remedy is to pump until the outlet pipes contain only seawater. If you check out your Jabsco handbook (or consult one on-line), it will even tell you how many pumps per metre of pipe.

We do have a holding tank, so periodically fizz with HCl. I couldn't begin to put numbers on that beyond 'as and when'...

 

[Dockhead]

If you've got them off, then just replace them. Far easier, and they need regular replacement anyway.

To prevent it in the future, pump through enough water so that no urine is left standing the lines, as the poster above stated. Besides that, give them regular doses of muriatic acid or lactic acid. I've been using the latter, since I am concerned that muriatic acid may degrade some parts of the toilet.

If you are using a holding tank, it should be plumbed so that the effluent does not go through an anti-syphon loop before getting to the tank. That way less pumping is required to clear the lines.

When pumping directly overboard, pump a LOT and instruct everyone on board to do likewise. How many guests and crew have we had who stop pumping as soon as they don't see anything in the bowl. That's what will give your lines arteriosclerosis. You need to explain.

 

[GrahamHR]

Dilute hydrochloric acid ( i.e. dilute "muriatic" acid) harms very few man made polymers. The PP, PE and natural and synthetic rubbers used in marine toilets are fine with it. Lactic acid is, if I remember correctly, an extremely weak organic acid; hardly worth using it at all to remove deposits.

 

[pcatterall]

Yes, ensure your pipes are left 'pee free'. One suggestion with the vinegar was to pump a few strokes of vinegar solution up the pipe, let it stand, then a few more strokes, let it stand. Continue until all the pipe has had a good lengthy soak.

 

[RichardS]

Lactic acid is, if I remember correctly, an extremely weak organic acid; hardly worth using it at all to remove deposits.

I had assumed that "lactic acid" was an error but perhaps not? I don't think I've ever seen a bottle of it in the lab.

Richard

 

[rogerthebodger]

This is the kind of problem I have had even with using white vinegar and lots of pumping.

This is what happened when I pumped neat hydrochloric acid (pool acid) in my case.

The problem with flushing any acid through with water is that the water will dilute the acid so much it becomes not very effective.

I simply remove my main head discharge pipe and beet the hell out of it on the jetty once a year or two.

 

[Freebee]

Look for old posts by headmistress she was at one time the fount of all knowledge about such problems!!

 

[thinwater]

I had assumed that "lactic acid" was an error but perhaps not? I don't think I've ever seen a bottle of it in the lab.

Richard

Lactic acid is sold in the US as a scale remover under the name CLR (Clacium, Lime, Rust) and is very effective. Testing shows it is the safest choice for aluminum (best scale removal per mil damage to metal).

 

[RichardS]

Lactic acid is sold in the US as a scale remover under the name CLR (Clacium, Lime, Rust) and is very effective. Testing shows it is the safest choice for aluminum (best scale removal per mil damage to metal).

Interesting .... this is the first time I can recall lactic acid being used in this connection. The usual acid used in scale removers in the UK is sulphamic acid which is stronger than lactic acid but weaker than hydrochloric acid which is presumably not usually sold for descaling applications in the UK for safety reasons. It is sold for descaling in many other European countries though.

I believe that lactic acid is similar in strength to citric acid and acetic acid which are often used in the UK for "home brewed / DIY" descaling applications although they are all fairly weak so a lot of acid would be needed for a serious scaling problem.

Richard

 

[thinwater]

Interesting .... this is the first time I can recall lactic acid being used in this connection. The usual acid used in scale removers in the UK is sulphamic acid which is stronger than lactic acid but weaker than hydrochloric acid which is presumably not usually sold for descaling applications in the UK for safety reasons. It is sold for descaling in many other European countries though.

I believe that lactic acid is similar in strength to citric acid and acetic acid which are often used in the UK for "home brewed / DIY" descaling applications although they are all fairly weak so a lot of acid would be needed for a serious scaling problem.

Richard

I recently did a series of tests for Practical Sailor Magazine, correlating the scale removal rate (I used old joker valves) with the rate of corrosion of standard metal samples (steel, brass, cast aluminum). Unsurprisingly, different acids are better in combination with certain metals. Interestingly, vinegar, by the time I corrected for the slow scale removal, was among the worst in terms of metal damage per unit scale removed. The corollary is that an outboard and an inboard suggest different acids. Finally, there is the matter of inhibitors (chemicals added to make the acids less aggressive to metals).

 

[Halo]

My discharge pipe is 7 m long so pumping through each pee would be too much. An annual purge using diluted brick cleaner has worked for me.
The method I use is
Have a 5 litre bottle of brick cleaner , a stirring stick , an old towel and plenty of fresh water available
Anchor or moor in open water on a calm day
Keep empty/purge switch in empty position (no sea water)
Half fill toilet bowl with fresh water and add about a cup full of brick cleaner , stir with a stick , let it stand 3/4 minutes
Pump out (not through) and keep refilling and pumping as above
Stop for a brew when fed up then carry on until you have used all the brick cleaner
Initially the dilute acid will fizz in the bowl but this will stop when all the deposits are dissolved.
As I say it works for me

 

[KellysEye]

I used to take the pipe off and beat it on the side of the pontoon which breaks it up. For any other limescale I used Muriatic acid, do not get it on hands if you do wash them quickly in water.

 

[Norman_E]

The problem is the use of seawater to flush. If you have big enough fresh water tanks do what I have done and convert the heads to freshwater flushing, which solves the problem permanently. I have actually intalled small electric pumps to supply the fresh water and only use the Jabsco pumps to pump out the bowls.

 

[rotrax]

This is the kind of problem I have had even with using white vinegar and lots of pumping.

This is what happened when I pumped neat hydrochloric acid (pool acid) in my case.

The problem with flushing any acid through with water is that the water will dilute the acid so much it becomes not very effective.

I simply remove my main head discharge pipe and beet the hell out of it on the jetty once a year or two.

I would respectfully suggest that that pipe might have been too far gone for any acid to work. The failure of the plastic parts look like breaks, not acid damage.

IMHO, and based on direct experience.

 

[Otter]

I had heard that it's only male pee that causes the calcification - is that true?

 

[thinwater]

I had heard that it's only male pee that causes the calcification - is that true?

a. Why would anyone have the data?
b. What difference could it possibly make?
c. Since the crystals are urate and oxylate, I seriously doubt this.

This is probably an urban legend based on the fact that urinals sometimes form scale and toilets do not. But the real difference is exposure to air, splashing, and flushing effectiveness. The toilets in the male restrooms do not scale because they flush properly.