Descaling Lavac Pump and Pipework

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earlybird

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I have just looked inside my Lavac pump. It is heavily scaled and presumably the associated pipework is in similar condition.
Hoping for an easy way of cleaning the system in-situ, I recalled that vinegar has been recommended to remove this scale. So, as an experiment, I broke off a small piece and immersed it in vinegar. (ASDA's own brand!). There was no discernable effect.
I wonder if brick cleaner, which is hydrochloric acid, might be more effective?
My plan would be to put a quantity, perhaps diluted a little, into the toilet bowl and pump it through the system, then perhaps repeating the dose a little later
I can't see it affecting the Blakes Seacocks, (I hope!!)
Has any-one tried this?
Are there any pifalls I've overlooked?
 
earlybird said:
I have just looked inside my Lavac pump. It is heavily scaled and presumably the associated pipework is in similar condition.
Hoping for an easy way of cleaning the system in-situ, I recalled that vinegar has been recommended to remove this scale. So, as an experiment, I broke off a small piece and immersed it in vinegar. (ASDA's own brand!). There was no discernable effect.
I wonder if brick cleaner, which is hydrochloric acid, might be more effective?
My plan would be to put a quantity, perhaps diluted a little, into the toilet bowl and pump it through the system, then perhaps repeating the dose a little later
I can't see it affecting the Blakes Seacocks, (I hope!!)
Has any-one tried this?
Are there any pifalls I've overlooked?
Click to expand...


brick cleaner ;)
 
We use acid to try and control the scale in the heads - Jabsco not Lavac but shouldn't be any different. For best results, work out the volume of the pipe work between head and skin fitting, fill head with that amount of dilute acid, pump through and leave to stand for a bit before repeating. Flush through and then put a few spoonfuls of veggie oil in and pump through. We do that occassionaly through the season and it seems to work.
 
duncan99210 said:
We use acid to try and control the scale in the heads - Jabsco not Lavac but shouldn't be any different. For best results, work out the volume of the pipe work between head and skin fitting, fill head with that amount of dilute acid, pump through and leave to stand for a bit before repeating. Flush through and then put a few spoonfuls of veggie oil in and pump through. We do that occassionaly through the season and it seems to work.
Click to expand...

Very different pumping arrangement beteen jabsco and lavac,

Incoming water is not pumped, just sucked** by the vacuum created in the bowl by the pump. So no silly little valves to worry about and absolutely no point in putting veggie oil in it!

I am not surprised vinegar has little effect it's fairly dilute solution of a very weak acid!

A sulphamic acid based descaler such as Fernox DS3 would be much better.

I think though if badly scaled and you don't want to remove the pipe to physically clean it go straight for the brick cleaner.

BUT
not all brick cleaners are hydrochloric acid based. You will have to check the labels and or the safety data sheets . B&Q are good with safety data sheets. You will find them on the website for all the brick, masonry and patio cleaners they sell.

** with apologies to any Physics teachers who may be reading this !
 
If you can get hold of some non-foaming marine toilet cleaner it should do the job.
Phosphoric acid is the active ingredient and it certainly de-scaled my Lavac pump without harming the valves.
I got hold of a couple of bottles of MOD surplus stuff which I have been using sparingly, but it must be available commercially (?).
 
Hello.
I have used brick cleaner made from hydrochloric acid in lavac systems to excellent effect.
I used quite strong solutions, so had to make myself scarce until the fumes cleared. I would think that they could be deadly.
Good luck.
 
Huttoft said:
Hello.
I have used brick cleaner made from hydrochloric acid in lavac systems to excellent effect.
I used quite strong solutions, so had to make myself scarce until the fumes cleared. I would think that they could be deadly.
Good luck.
Click to expand...

Hydrochloric acid is a strong acid! It will therefore react quite quickly with limescale etc.

In its concentrated form its about 36% HCl IIRC. To use for limescale removal I would dilute it to the equivalent of about 5% ( maybe little more if heavily scaled)

Brick cleaners are not so concentrated, about 20% IIRC . Use the figure on the container or in the MSDS to dilute it to 5% or so.

The fumes are not only unpleasant but hazardous and corrosive to other susceptible bits and pieces
 
Huttoft said:
Hello.
I have used brick cleaner made from hydrochloric acid in lavac systems to excellent effect.
I used quite strong solutions, so had to make myself scarce until the fumes cleared. I would think that they could be deadly.
Good luck.
Click to expand...

I always have a concern that using really powerful cleaners will do damage to the rubber Lavac valves, especially the exhaust, affecting the seal and allowing seepage back into the bowl. I have used Lee Sanitation's LeeScale with success in the past, but - because our system is quite complex, with two diverter valves plus the main Lavac pump -- I go for a complete strip down of the system about every 18 months.
 
samwise said:
I always have a concern that using really powerful cleaners will do damage to the rubber Lavac valves, especially the exhaust, affecting the seal and allowing seepage back into the bowl. I have used Lee Sanitation's LeeScale with success in the past, but - because our system is quite complex, with two diverter valves plus the main Lavac pump -- I go for a complete strip down of the system about every 18 months.
Click to expand...

Leescale is still quite strongly acidic with a pH of only 1.4
It is based on phosphoric and citric acids.
 
Thanks for comments. Since I already have some Brick Cleaner, which says hydrochloric acid on the label, I'll start with that, perhaps somewhat diluted at first.
I can use the pump inspection-plate as a test piece.
 
I recently used hydrochloric acid (bought as Muriatic acid) to de scale my lavac pump and pipes. It worked, big style, very quick, loads of fumes. HOWEVER maybe I should have used it diluted, or maybe my pump was very old, but afterwards the plastic pump body went 'chalky' and developed major cracks- totally ruined.(Rubber seals were fine though). Bit of a problem as I was just about to transit the Panama Canal and one needs a working heads for the pilot advisor and linehandlers.... still only $333 for a new pump and postage :(
 
phanakapan said:
I recently used hydrochloric acid (bought as Muriatic acid) to de scale my lavac pump and pipes. It worked, big style, very quick, loads of fumes. HOWEVER maybe I should have used it diluted, or maybe my pump was very old, but afterwards the plastic pump body went 'chalky' and developed major cracks- totally ruined.(Rubber seals were fine though). Bit of a problem as I was just about to transit the Panama Canal and one needs a working heads for the pilot advisor and linehandlers.... still only $333 for a new pump and postage :(
Click to expand...

From the spec for the pump
Materials In Contact With Fluid: Glass-filled Polypropylene, Acetal, Nitrile, Stainless Steel

I guess what failed was made of acetal. It's hydrolysed by acids. Polypropylene should have been OK.

Maybe an old pump made of different materials?
 
I used Vanosolve which "contains hydrochloric acid".
Worked well on my old Lavac bowl.
I suspect old pipes should be replaced though.
And a badly furred pump needs dismantling.
In fact I replaced mine with a better model recently.
 
I would worry about using hydrochloric acid and the effect it may have on the discharge seacock. From what I remember of my school chemistry, you may get a bit of fizzing froom the bronze of the seacock when in contact with this acid. At circa £120 for a Blakes seacock of the appropriate size, I would prefer to put up with a bit of calcification in the rest of the system.
 
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