green salt/fur stuff around a isloating valve..

[helptavner]

?? was up in the roof, and saw this green stuff that comes off when you touch it.. like green salt...???? around one side of the isolating valve.. doesnt appare to be leaking... touched with tissue.. just the green stuff came off ??

anyone please/ get scared with with it being the large tank up in the roof..

 

[HERTS P&D]

Clean off with wire wool or metal brillo pad.

Andy

 

[helptavner]

i didnt like to start cleaning away incase it was stopping a leak..

its up in the roof attaching to the large tank, what is the stufff??

it seemed to come off with touching it>??

thanks

 

[MJN]

It is called 'verdigris' and is basically one of the byproducts of copper corrosion. It is likely that the valve has been leaking, perhaps by so little an amount that it evaporates before causing any other signs/damage and may well have sealed itself. Check to make sure it is nothing more than this and just clean it off (if nothing else so you can see if it reoccurs).

Mathew

 

[vicvapour]

It is called 'verdigris' and is basically one of the byproducts of copper corrosion. It is likely that the valve has been leaking, perhaps by so little an amount that it evaporates before causing any other signs/damage and may well have sealed itself. Check to make sure it is nothing more than this and just clean it off (if nothing else so you can see if it reoccurs).

Mathew

Verdigris is the name of a green pigment and only occurs when acetic acid is added to copper.

Last time i looked there was no acetic acid in a boiler.

Again offering poor information to people, dear dear me.

 

[MJN]

Kids eh... do they teach you nothing at school these days?

Copper oxidises in air to form copper oxide which, in the presence of water, forms copper carbonate - the key component of verdigris and is green/blue in colour. Further info on its wiki page if you're interested:

http://en.wikipedia.org/wiki/Copper(II)_carbonate

Mathew

 

[vicvapour]

Kids eh... do they teach you nothing at school these days?

Copper oxides in air to form copper oxide which, in the presence of water, forms copper carbonate - the key component of verdigris and is green/blue in colour. Further info on its wiki page if you're interested:

http://en.wikipedia.org/wiki/Copper(II)_carbonate

Mathew

Read it again MJN!

 

[vicvapour]

http://en.wikipedia.org/wiki/Verdigris

 

[libby lou lou]

I believe it's poisonous.

 

[vicvapour]

I believe it's poisonous.

Yeah it is pretty toxic that stuff

 

[MJN]

Verdigris is the common name for a green pigment obtained through the application of acetic acid to copper plates[1] or the natural patina formed when copper, brass or bronze is weathered and exposed to air or seawater over a period of time. It is usually a basic copper carbonate, but near the sea will be a basic copper chloride.[2] If acetic acid is present at the time of weathering, it may consist of copper(II) acetate.

Which bit of that did you not understand?

Note the following formula for the production of copper carbonate:

2 Cu (s) + H2O (g) + CO2 + O2 → Cu(OH)2 + CuCO3 (s)

Copper, water, carbon dioxide, oxygen. Combine them to form copper carbonate (and copper hydroxide but that reforms with the CO2 to form more carbonate as the wiki article discusses).

If none of this rings any bells, perhaps you can explain to the OP what you think the green deposits he's seeing are?

Mathew

 

[Charnwood]

or the natural patina formed when copper, brass or bronze is weathered and exposed to air or seawater over a period of time.

Now who's not reading properly?

 

[helptavner]

the isolating valve was very furry.. but dry - i touched it (didnt want to prod to much) just a bit of green flaked off?
but seemed dry

just leave then i guess??!