Lime on copper

[verdigrey]

Hi everyone ,
Does anyone know how corrosive Lime is to copper ? I have been looking at a job recently where the customer has rendered the wall themselves with a Lime and thread ( or something else ) mix . about 1" thick . They have put it over a vertical 15 mm copper cold water main pipe . I know cement can eat into copper , but does Lime do the same ? Thanks

 

[albatross]

It's very corrosive. It's lime in cement and plaster that corrodes copper. They used it in the '60's to dissolve cattle carcass's that had foot and mouth.

 

[verdigrey]

Thanks for your quick replies . I have suggested to the customer that the cold main should be replaced anyway with a protected 22 pipe ( they want a Thermal store ) , but they seem reluctant for some reason . Cheers guys .

 

[AWheating]

put it in an email and earn your corn.

 

[Killy Bing]

Copper is quite amazing in respect of it being extremely corrosion resistant bar when in contact with alkali metals, sulfur, ammonia and any oxidising acids.

albatross pretty sure sulfur makes up part of the gypsum used in plaster and the concrete.
Concrete has fly ash in it which gives off ammonia too (according to my dad next to me)

copper deals very well with alkaline's usually, i think i even read that limestone chippings can be used to backfill copper pipes in the ground to protect them.

if anything, id say the render (if no cement or gypsum was used) would likely protect it!!!

lime on steel or iron on the other hand!!

 

[kay-jay]

Copper is quite amazing in respect of it being extremely corrosion resistant bar when in contact with alkali metals, sulfur, ammonia and any oxidising acids.

albatross pretty suresulfur makes up part of the gypsum used in plaster and the concrete.
Concrete has fly ash in it which gives off ammonia too (according to my dad next to me)

copper deals very well with alkaline's usually, i think i even read that limestone chippings can be used to backfill copper pipes in the ground to protect them.

if anything, id say the render (if no cement or gypsum was used) would likely protect it!!!

lime on steel or iron on the other hand!!

ha ha you gonna insure it for him then billy?

you could be right about this though billy, i was always told it was lime in plaster that corroded copper, but it turns out that it is not really used that much these days. except some types of fireproof plaster.

so it could be gypsum or it could just be out of date info as lime plaster isnt prevalent any more?
btw gypsum is pretty good stuff. i treat water with it prior to brewing beer