acid descaling of toilet pipe

Bosun Higgs

Bosun Higgs

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boat is out of the water but when the yard built the boat, they undoubtedly fitted the toilet outlet pipe before fitting the deck and woodwork. So I need to descale it in situ. Two obvious questions:

1/ and this I should know but if I simply bung up the outlet sea cock with a cork, will brick acid ie dilute hydrochloric dissollve the bronze of a blakes seacock?
2/ toilet is the typical Jabsco. If I flush some acid down the toilet and then bung up the outlet, will the gasses liberated blow up the toilet =- pressure against the non return bit. Will they dissolve the internal bits of the toilet mechanism.

Yes I know that I should really disconnect the toilet pipe but believe me, that is a BIG job possibly involving a jigsaw on the woodwork.
 
If it is really bunged up, unlikely that just acid will clear it. Tests done in PBO recently on different treatments and even the strongest had little effect on really hard scale. No real alternative to replacing the pipe.
 
I cannot see how you are going to get the acid over the anti-suphon loop in the pipe if you close the seacock. If you leave the seacock open then the acid beyond the anti-syphon loop will run out. The only part of the pipe it is feasable to descale your way is between the pump and the anti-syphon loop.
 
Buy strong vinegar and add to toilet from time to time at flushing. Helps, I heard. It's also safe way to clean and disinfect, certainly better than many toilet cleaning chemicals giving off chemical weapon gases...
For piping any acid can be used, if you can fill the pipe for some time; citric acid is safe on plastics and metals.
 
Answering the original question, hydrochloric acid in the concentration that I was able to buy had no visible effect on brass, DZR or bronze after 20 minutes of immersion. The acid was 20% concentration.

I regularly use HCl on my toilet. The gases simply bubble through, dependent on where the salts are. I buy 500 ml bottles of acid in Greece, put about a third of it in the bowl, pump two or three times, wait until gassing stops, add the next third, pump, wait, add the rest, pump again. Far better done regularly when the salts are soft. Once hardened I find it impossible to remove them with acid treatment.
 
nigelmercier said:
I have actually considered a device to time my electric flush, then ring an alarm if it isn't the full 10 seconds. What is wrong with people!
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Whenever we have friends on board they always get the 'count to ten slowly' talk. Invariably they flush for three or four seconds. Not a major problem over a weekend but you can see why charter boats always smell... (Don't even get my wife on the subject of men who can't sit down whilst underway - at least two 'friends' will never be invited on board again!!!)
 
If out of the water, find a hose tail or a bung with a hole drilled through, fit a length of pipe, hold the end above the level of the anti-syphon if fitted & fill it with whatever suits you for de-scaling.

As Vic said, if its hard scale the acid will have little effect, but, if you can get to most of the pipework, you may be able to apply percussive maintenace to those bits & break up the hard stuff.

Rinse & Repeat
 
Ariadne said:
Why can't you split the pipe at the anti-syphon valve? Then you fill with acid from both ends nop problem. Reconect and flush with fresh water after about 20 mins.

Acid is the best way we have found to clean the pipes, nothing else touches it.
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No way I can get to the anti syphon valve which is behind the inner lining ( Sadler style construction) but in any case, isnt the anti syphon valve on the inflow pipe?
 
Bosun Higgs said:
No way I can get to the anti syphon valve which is behind the inner lining ( Sadler style construction) but in any case, isnt the anti syphon valve on the inflow pipe?
Click to expand...

Checking/servicing the antisyphon valve(s) a bit of a problem then!


If the toilet is below the heeled water line there should be an antisyphon valve in the inlet, in a loop between the pump and the bowl. There also should be one in the discharge otherwise while the seacock is open you are relying on the (aptly named) joker valve.
 
vyv_cox said:
Answering the original question, hydrochloric acid in the concentration that I was able to buy had no visible effect on brass, DZR or bronze after 20 minutes of immersion. The acid was 20% concentration.

I regularly use HCl on my toilet. The gases simply bubble through, dependent on where the salts are. I buy 500 ml bottles of acid in Greece, put about a third of it in the bowl, pump two or three times, wait until gassing stops, add the next third, pump, wait, add the rest, pump again. Far better done regularly when the salts are soft. Once hardened I find it impossible to remove them with acid treatment.
Click to expand...


+ 1. Same here. In the UK, you can find the standard "brick cleaner" from B&Q, Trago Mills and such like which is moderately concentrated HCl. Do as Vyv writes...
 
I went to Booker last week and bought 5liters of vinegar. Poured it into the bowl and flushed it through. As soon as it was all gone I closed the outlet sea cook and left it over night.
When I opened the sea clock the next day the release of gas gurgling out worried me. Dashing up top revealed a cloud of scale flakes slowly sinking, a good dose of pumping saw more clouds of flakes so it had some effect.
Today, après a good curry last night in Oban and half way across the deserted Firth of Lorne I had to go. The poor heads was not its usual good self and a worrying ten minutes of pumping with no results had my stress level up, doubly so as the
'Isle of Mull' ferry wash was only a matter of time.
Thankfully cycling the flush/ empty lever, some foul language and a load of pumping got a result..

I think I might have damaged the joker valve...

A return to the good old days of ' bucket-and-chuck-it' seems in order until I get back home.
 
Closing the seacock was not a good idea. I guess that the gas pressure generated has inverted the joker valve. With luck it will resume its normal position once some solids have gone through, or otherwise you may need to take it out and turn it back.
 
vyv_cox said:
Closing the seacock was not a good idea. I guess that the gas pressure generated has inverted the joker valve. With luck it will resume its normal position once some solids have gone through, or otherwise you may need to take it out and turn it back.
Click to expand...
That's what I hope I've done!
My reasoning for closing the sea cock was to hold the vinegar in as I suspect it's heavier than sea water. I didn't really anticipate such a reaction...
 
VicS said:
Checking/servicing the antisyphon valve(s) a bit of a problem then!


.
Click to expand...

No its not a problem Vic - its impossible. I know I have some sort of antisyphon on the inlet because an elsan dispenser is beld into it. I dont even know if there is one on the outlet but if there should be one then I think there will be since the boat was built by Bowman.
 
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