The flow to my bath has dwindled over the years, it's a conventional
vented cylinder and 3/4" copper pipes, is there likely to be any
benefit in dosing the cold water tank with sulphamic acid and then
recirculating through the bath tap connection with a pump?

AJH

On 31/07/2018 21:38, wrote:
The flow to my bath has dwindled over the years, it's a conventional
vented cylinder and 3/4" copper pipes, is there likely to be any
benefit in dosing the cold water tank with sulphamic acid and then
recirculating through the bath tap connection with a pump?

A tub of fernox DS3 will make enough gallons to fill the tank and the
cistern, so yup recirculating with a pump for a few hours should do the
trick. Keep the immersion on for better performance (but don't let the
cistern get too hot if its plastic - they can go droopy if not well
supported)


--
Cheers,

John.

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Probably only a leak I'd say!
Sounds a bit drastic to me. If the water is really that hard, maybe some
way to make it less so might be a good idea. . How many years has it taken
to be noticeable?
Brian

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This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

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wrote in message
...
The flow to my bath has dwindled over the years, it's a conventional
vented cylinder and 3/4" copper pipes, is there likely to be any
benefit in dosing the cold water tank with sulphamic acid and then
recirculating through the bath tap connection with a pump?

AJH

Yes we all go droopy in the heat if not supported, what?
I'm not convinced about this to be honest. I remember when we first moved
in here and had flow issues in the bath my father trying this sort of thing.
It did not work and it found a few pin hole leaks in the plumbing under the
bath which in the end needed the pipes replacing and so we got a new bath
and new pipes in the end. The question I always wondered about was how come
the particular pipes were coated in scale inside but the very old but wider
ones in the loft down to the bath and from the cylinder to under the floor
did not though clearly they were older by some years.The plumber at the time
said often life is like that, and shrugged. This was many many ears ago in
the 1960s.
Brian

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This newsgroup posting comes to you directly from...
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Note this Signature is meaningless.!
"John Rumm" wrote in message
o.uk...
On 31/07/2018 21:38, wrote:
The flow to my bath has dwindled over the years, it's a conventional
vented cylinder and 3/4" copper pipes, is there likely to be any
benefit in dosing the cold water tank with sulphamic acid and then
recirculating through the bath tap connection with a pump?

A tub of fernox DS3 will make enough gallons to fill the tank and the
cistern, so yup recirculating with a pump for a few hours should do the
trick. Keep the immersion on for better performance (but don't let the
cistern get too hot if its plastic - they can go droopy if not well
supported)


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
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| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 01/08/2018 00:53, John Rumm wrote:
On 31/07/2018 21:38, wrote:
The flow to my bath has dwindled over the years, it's a conventional
vented cylinder and 3/4" copper pipes, is there likely to be any
benefit in dosing the cold water tank with sulphamic acid and then
recirculating through the bath tap connection with a pump?

A tub of fernox DS3 will make enough gallons to fill the tank and the
cistern, so yup recirculating with a pump for a few hours should do the
trick. Keep the immersion on for better performance (but don't let the
cistern get too hot if its plastic - they can go droopy if not well
supported)


My first house had a rivetted galvanised hot water tank, and many metres
of iron pipe getting on for 2 inches OD in the gravity DHW system which
must, once upon a time, have gone to a coal stove in the scullery. Some
of this pipework was almost completely blocked with scale, there must
have been kilogrammes of it in the whole system. My recollection is that
while this particular type of scale dissolves readily enough in
hydrochloric acid, the dissolution rate is quite slow in weak acids. So
while I agree with the theory of your analysis, I'd worry how well it
would work in practice. Heating should help.

On 01/08/2018 11:53, newshound wrote:
On 01/08/2018 00:53, John Rumm wrote:
On 31/07/2018 21:38, wrote:
The flow to my bath has dwindled over the years, it's a conventional
vented cylinder and 3/4" copper pipes, is there likely to be any
benefit in dosing the cold water tank with sulphamic acid and then
recirculating through the bath tap connection with a pump?

A tub of fernox DS3 will make enough gallons to fill the tank and the
cistern, so yup recirculating with a pump for a few hours should do
the trick. Keep the immersion on for better performance (but don't let
the cistern get too hot if its plastic - they can go droopy if not
well supported)


My first house had a rivetted galvanised hot water tank, and many metres
of iron pipe getting on for 2 inches OD in the gravity DHW system which
must, once upon a time, have gone to a coal stove in the scullery. Some
of this pipework was almost completely blocked with scale, there must
have been kilogrammes of it in the whole system. My recollection is that
while this particular type of scale dissolves readily enough in
hydrochloric acid, the dissolution rate is quite slow in weak acids. So
while I agree with the theory of your analysis, I'd worry how well it
would work in practice. Heating should help.

Yup heating helps greatly...

The fernox instructions for a manual descale, suggest a minimum of 4
hours with the temp between 50 to 60 deg C.

You may get faster results with a continous recirculation system.

https://fernox.com/cpt_downloads/des...stem-manually/



--
Cheers,

John.

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| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Wed, 1 Aug 2018 00:53:22 +0100, John Rumm
wrote:

On 31/07/2018 21:38, wrote:
The flow to my bath has dwindled over the years, it's a conventional
vented cylinder and 3/4" copper pipes, is there likely to be any
benefit in dosing the cold water tank with sulphamic acid and then
recirculating through the bath tap connection with a pump?

A tub of fernox DS3 will make enough gallons to fill the tank and the
cistern, so yup recirculating with a pump for a few hours should do the
trick. Keep the immersion on for better performance (but don't let the
cistern get too hot if its plastic - they can go droopy if not well
supported)

Thanks, to clarify I intend to first empty the galvanised steel cold
water tank and wet vacuum any scale in the bottom. I was only going
to part fill it and would add the fernox DS3 as you advise. I was then
intending to attach a spare central heating pump to the 15mm shower
connection which is TEEd off the bath hot water tap and return the
water to the cold water tank via a length of HEP20 dumping back into
the cold water tank.

AJH

On Wed, 01 Aug 2018 17:27:40 +0100, wrote:

Thanks, to clarify I intend to first empty the galvanised steel cold
water tank and wet vacuum any scale in the bottom. I was only going
to part fill it and would add the fernox DS3 as you advise.

Fernox DS3 is OK on glavanised, I take it?


Thomas Prufer

On Wednesday, 1 August 2018 17:27:44 UTC+1, wrote:
On Wed, 1 Aug 2018 00:53:22 +0100, John Rumm
wrote:

On 31/07/2018 21:38, wrote:
The flow to my bath has dwindled over the years, it's a conventional
vented cylinder and 3/4" copper pipes, is there likely to be any
benefit in dosing the cold water tank with sulphamic acid and then
recirculating through the bath tap connection with a pump?

A tub of fernox DS3 will make enough gallons to fill the tank and the
cistern, so yup recirculating with a pump for a few hours should do the
trick. Keep the immersion on for better performance (but don't let the
cistern get too hot if its plastic - they can go droopy if not well
supported)

Thanks, to clarify I intend to first empty the galvanised steel cold
water tank and wet vacuum any scale in the bottom. I was only going
to part fill it and would add the fernox DS3 as you advise. I was then
intending to attach a spare central heating pump to the 15mm shower
connection which is TEEd off the bath hot water tap and return the
water to the cold water tank via a length of HEP20 dumping back into
the cold water tank.

AJH

how do you plan to stop it attacking the copper pipe?


NT

On Wed, 01 Aug 2018 19:55:48 +0200, Thomas Prufer
wrote:

On Wed, 01 Aug 2018 17:27:40 +0100, wrote:

Thanks, to clarify I intend to first empty the galvanised steel cold
water tank and wet vacuum any scale in the bottom. I was only going
to part fill it and would add the fernox DS3 as you advise.

Fernox DS3 is OK on glavanised, I take it?

It says it's safe to use but I don't know until an expert comes along.

My guess is the acid's affinity for the carbonate is higher than that
for metal. it's moot about the zinc as that seems to have gone from
the inside of the tank.

I hope if I use the right dose it will deal with the lime scale and
leave the metals alone.

AJH

On 01/08/18 20:27, wrote:
On Wed, 01 Aug 2018 19:55:48 +0200, Thomas Prufer
wrote:

On Wed, 01 Aug 2018 17:27:40 +0100, wrote:

Thanks, to clarify I intend to first empty the galvanised steel cold
water tank and wet vacuum any scale in the bottom. I was only going
to part fill it and would add the fernox DS3 as you advise.

Fernox DS3 is OK on glavanised, I take it?

It says it's safe to use but I don't know until an expert comes along.

My guess is the acid's affinity for the carbonate is higher than that
for metal. it's moot about the zinc as that seems to have gone from
the inside of the tank.

I hope if I use the right dose it will deal with the lime scale and
leave the metals alone.

AJH

Most decsalers are weak enough acids to leave metals alone. HCl is not
one of them. DAMHIKT




--
€œA leader is best When people barely know he exists. Of a good leader,
who talks little,When his work is done, his aim fulfilled,They will say,
€œWe did this ourselves.€�

ۥ Lao Tzu, Tao Te Ching

On 01/08/2018 20:40, The Natural Philosopher wrote:
On 01/08/18 20:27, wrote:
On Wed, 01 Aug 2018 19:55:48 +0200, Thomas Prufer
wrote:

On Wed, 01 Aug 2018 17:27:40 +0100, wrote:

Thanks, to clarify I intend to first empty theÂ* galvanised steel cold
water tankÂ* and wet vacuum any scale in the bottom. I was only going
to part fill it and would add the fernox DS3 as you advise.

Fernox DS3 is OK on glavanised, I take it?

It says it's safe to use but I don't know until an expert comes along.

My guess is the acid's affinity for the carbonate is higher than that
for metal. it's moot about the zinc as that seems to have gone from
the inside of the tank.

I hope if I use the right dose it will deal with the lime scale and
leave the metals alone.

AJH

Most decsalers are weak enough acids to leave metals alone. HCl is not
one of them. DAMHIKT

DS3 is not HCL, but sulfamic acid (H3NSO3), generally safe on metals,
although may dull chrome on prolonged exposure.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Wed, 1 Aug 2018 22:50:55 +0100, John Rumm
wrote:

DS3 is not HCL, but sulfamic acid (H3NSO3), generally safe on metals,
although may dull chrome on prolonged exposure.

Zinc gets eaten by pretty much everything, though.

I found a patent, including this language: "Even at room temperature Islamic
acid rapidly attacks zinc galvanize; in aqueous solution at concentrations as
low as 1.5% by weight, it is capable of completely dissolving a zinc galvanize
coating from a ferrous metal base in two to three hours. Repeated use of Islamic
acid even for short periods will severely corrode zinc galvanized equipment. The
corrosive effect of the acid on zinc increases with temperature, and galvanize
may be removed in less than 30 minutes at a temperature of 140 F."

And also this: "Weak acids such as citric acid, formic acid and sulphuric acid
are suitable for use with metals such as aluminum, zinc, copper and nickel.
Although these metals will be affected by these acids, this will be much less
severe."

A while back I asked a bunch of chemists with what to descale a pot with an
intact, thick layer of zinc -- and didn't get a useful answer. I ended up using
a wet stiff brush and elbow grease. This got rid of enough scale to be useful,
say 80%, and was surprisingly efficient. The removed scale formed a milky soup
that abraded the remaining scale very well...

In this case: if the zinc is gone, it won't be attacked. Just keep an eye on it,
OK?


Thomas Prufer

On 02/08/18 10:49, Thomas Prufer wrote:
On Wed, 1 Aug 2018 22:50:55 +0100, John Rumm
wrote:

DS3 is not HCL, but sulfamic acid (H3NSO3), generally safe on metals,
although may dull chrome on prolonged exposure.

Zinc gets eaten by pretty much everything, though.

I found a patent, including this language: "Even at room temperature Islamic
acid

WTF is Islamic acid?

Stuff you throw in peoples faces?



--
"A point of view can be a dangerous luxury when substituted for insight
and understanding".

Marshall McLuhan

On 02/08/2018 10:49, Thomas Prufer wrote:
On Wed, 1 Aug 2018 22:50:55 +0100, John Rumm
wrote:

DS3 is not HCL, but sulfamic acid (H3NSO3), generally safe on metals,
although may dull chrome on prolonged exposure.

Zinc gets eaten by pretty much everything, though.

I found a patent, including this language: "Even at room temperature Islamic
acid rapidly attacks zinc galvanize; in aqueous solution at concentrations as
low as 1.5% by weight, it is capable of completely dissolving a zinc galvanize
coating from a ferrous metal base in two to three hours. Repeated use of Islamic
acid even for short periods will severely corrode zinc galvanized equipment. The
corrosive effect of the acid on zinc increases with temperature, and galvanize
may be removed in less than 30 minutes at a temperature of 140 F."

And also this: "Weak acids such as citric acid, formic acid and sulphuric acid
are suitable for use with metals such as aluminum, zinc, copper and nickel.
Although these metals will be affected by these acids, this will be much less
severe."

A while back I asked a bunch of chemists with what to descale a pot with an
intact, thick layer of zinc -- and didn't get a useful answer. I ended up using
a wet stiff brush and elbow grease. This got rid of enough scale to be useful,
say 80%, and was surprisingly efficient. The removed scale formed a milky soup
that abraded the remaining scale very well...

In this case: if the zinc is gone, it won't be attacked. Just keep an eye on it,
OK?


Thomas Prufer

Interesting. IIRC the De Longhi coffee machine warns against sulphamic
acid, there may be zinc plated screws in there. Lactic acid, apparently:

https://www.delonghi.com/Global/coun...odecalk500.pdf

In article ,
wrote:
The flow to my bath has dwindled over the years, it's a conventional
vented cylinder and 3/4" copper pipes, is there likely to be any
benefit in dosing the cold water tank with sulphamic acid and then
recirculating through the bath tap connection with a pump?

Do check there's not a thingie just inside the tap spout that's got furred
up.

--
*He who laughs last, thinks slowest.

Dave Plowman London SW
To e-mail, change noise into sound.

On 02/08/2018 15:54, Dave Plowman (News) wrote:
In article ,
wrote:
The flow to my bath has dwindled over the years, it's a conventional
vented cylinder and 3/4" copper pipes, is there likely to be any
benefit in dosing the cold water tank with sulphamic acid and then
recirculating through the bath tap connection with a pump?

Do check there's not a thingie just inside the tap spout that's got furred
up.

Yup good point - those aerator things are prone to scaling and getting
blocked.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/