descaling the khazi

wotayottie

wotayottie

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prompted by this weeks PBO article.

How do you do it with the boat afloat? Cant pump the solution into the pipe with the cock closed or do you pump it in cock open and then shut the cock? Or do you disconnect the hose at thye toilet end and with the cock closed pour the solution into the hose?

Any chemists tell me the effect of brick acid ie dilute hydrochloric, on a bronze seacock? Its cheaper than special descaling stuff.
 
I'd say descaling the discharge pipe that way is impractical especially with the anti-syphon loop in the pipe.

I think most people give the pipe some heavy wacks to dislodge the scale then flush.

However the best way is to remove the pipe and descale but then you may as well fit new.
 
Bronze does not have much corrosion resistance to 10% hydrochloric acid at around 20C. However, I still use it from time to time to clear pipes. I tend to pump through fresh water followed by enough cold 5% hydrochloric acid solution to fill the pipe and then a tiny bit of water to clear the pump. I close the valve for 30 mins. and then open it and flush with fresh water 30mins. later. I don't have any anti-syphon valve to worry about so can keep pipes full easily.

I think this should minimise corrosion by keeping acid concentration down in vicinity of the valve.

I use a different method for head with holding tank but same principle of keeping acid away from valve as much as possible.

However, I always pump 20-30 times after use to minimise buildup in first place. I also dismantle pipe every 1-2 years to check and valve & pipe always seem completely clear. This probably contributes more to clean pipes than very infrequent hydrochloric acid flush and acetic acid flush 2-3 times each year.
 
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You could go into any of the previous threads on this subject or ......... here we go again.

We have been living aboard for 17 years and have 2 lavacs in daily use. I have not had to dismantle our pumps for about the last 6/7 years, except recently I had a diaphragm, which developed a split. I found the interior of the pump and the tail of the outlet pipe to be reasonably clean.

I use dilute hydrochloric acid. The bottles purchased in France are a 23% solution and I dilute this further with 1 ltr acid to 3 ltrs of hot water. I pump the bowl dry and then add the mixture to the normal water level. I pump this so that it just leaves the bowl and leave this to stand for about 15 minutes. I then refill again to the same level and pump 'till just dry. I leave this for a further 15 minutes. The 4 ltrs of the acid solution allows me to do this about 4 times. If you or your partner are watching over the side, you will see a very satisfying result.

I do this about once a month and have never seen any problem, when I have dismantled my Blakes bronze seacocks.
 
A bottle of coke

Funny you should mention this. I did mine yesterday. Had some scaling around the bottom pipe on the pan

Poured a 500ml of coke in last night before bed. Quick scrub this morning with the toilet brush and it's sparking..
 
Stuff I buy in Spain almost certainly be around same strength Frankie-H uses (well it won't be 36% as it isn't fuming). Sounds as if he is using a similar concentration to me but uses hot water and only leaves for 15 minutes. Good to know he gets no signs of corrosion.

Not too surprised as the hydrochloric acid won't attack the metal all that rapidly, just not suitable for long term use (i.e don't store it in bronze containers).
 
Mistroma said:
Stuff I buy in Spain almost certainly be around same strength Frankie-H uses (well it won't be 36% as it isn't fuming). Sounds as if he is using a similar concentration to me but uses hot water and only leaves for 15 minutes. Good to know he gets no signs of corrosion.

Not too surprised as the hydrochloric acid won't attack the metal all that rapidly, just not suitable for long term use (i.e don't store it in bronze containers).
Click to expand...
I use sulphamic acid as my decalcifier - it is more effective than the mineral acids at softening the deposit.
That is pumped through the toilet every time I descale the two kettles which is about monthly.
Every 5 years, I take the pipe out, block one end and pour in the solution, cork the other end and leave it for 24 hours before thoroughly manipulating the pipe and getting out all the blockages - having a translucent pipe helps.
I also plug the outlet and stand sulphamic acid in the open ball valve, before getting that out, usually mechanically.
Just pumping acids through, however regularly done, is in my experience wishful-thinking anti-block maintenance.
The most difficult-to-remove deposit is the one in the top of the ball-cock - I have to revert to hammer and chisel.
 
wotayottie said:
prompted by this weeks PBO article.

How do you do it with the boat afloat? Cant pump the solution into the pipe with the cock closed or do you pump it in cock open and then shut the cock? Or do you disconnect the hose at thye toilet end and with the cock closed pour the solution into the hose?

Any chemists tell me the effect of brick acid ie dilute hydrochloric, on a bronze seacock? Its cheaper than special descaling stuff.
Click to expand...

When I descale the sea water cooling areas of the engines, I use Rydlyme (http://www.rydlymemarine.co.uk/).

How about using this with the khazi?
 
Not sure what sort of diets you lot have, but I've never descaled the toilet pipes on a boat. I've had the current boat for 16 years. But I always ensure that the toilet is flushed generously.
 
Tried the Coke, followed by hydrochloric acid last season. Found both to be a waste of time as there was too much limescale built up over the years. Lots of bubbling and gas given off but just ended up with blockages and one joker valve turned inside out.

Had to replace both heads outlet pipes which is what I should have done in the first place.
 
pvb said:
Not sure what sort of diets you lot have, but I've never descaled the toilet pipes on a boat. I've had the current boat for 16 years. But I always ensure that the toilet is flushed generously.
Click to expand...

Worth mentioning. Hardly any scale forms if you are sure to flush all the way through every time. Requires quite a bit of pumping, alas, depending on your anti-syphon arrangements. Yet another powerful argument for electric bogs on board.
 
Dockhead said:
Worth mentioning. Hardly any scale forms if you are sure to flush all the way through every time. Requires quite a bit of pumping, alas, depending on your anti-syphon arrangements. Yet another powerful argument for electric bogs on board.
Click to expand...

Mine doesn't have an anti-syphon valve, and has a short outlet pipe as a result.
 
Dockhead said:
Worth mentioning. Hardly any scale forms if you are sure to flush all the way through every time. Requires quite a bit of pumping, alas, depending on your anti-syphon arrangements. Yet another powerful argument for electric bogs on board.
Click to expand...

Nah, electric bogs are the worst for scaling. People just tend to push the button until everything is out of sight and then leave it.
 
theoldsalt said:
I'd say descaling the discharge pipe that way is impractical especially with the anti-syphon loop in the pipe.

I think most people give the pipe some heavy wacks to dislodge the scale then flush.

However the best way is to remove the pipe and descale but then you may as well fit new.
Click to expand...

Modern boat and it looks to me as if the builder fitted the outlet hose and toilet before adding the deck. It would be an angle grinder job to change the tube.
 
I used to close the seacocks take the pipe off and bash it on the dock. I once tried Muriatic acid but it would have taken gallons of the stuuff to get all limescale out. Bashing it is free.
 
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