[TheForge] sealing copper pee patina

[GRAF]

Peter,
 The roof top patinas are being constantly replenished as more copper 
combines with available sulfur.
If you were to look at any area subject to abrasion from traffic or 
intense water flow you'd see areas where it is brown. On a roof with 
wood shingles the spots would be bright red shiny copper.

The copper sulphate is mildly soluble in water and copper roofs 
eventually dissolve. Valley's and gutters beneath Spanish tile roofs get 
holes dissolved through them in areas that the watter is channeled.

Peter Hirst wrote:
> I am not so sure about copper patinas not being permanent.  You se a 
> lot of copper roofs that stay a nice green indefinitely, (St Matthews 
> cathedral in DC, for an AMerican example) and I am sure no one is up 
> there periodically, uuh, renewng the treatment.  I have a commper 
> sculpture in my shop yard that was treated in this way that has 
> remained stable for years.   Bears more research, I think.
>
>
> ----- Original Message ----- From: "Woolley" <wjec at verizon.net>
> To: "Sponsored by ABANA" <theforge at mailman.qth.net>
> Sent: Wednesday, February 20, 2008 9:00 AM
> Subject: Re: [TheForge] sealing copper pee patina
>
>
>> lee robbins wrote:
>>> Thanks for the copper info. i wondered about the
>>> patina after the cat pee information on steel. I just
>>> got some tung oil for my tool handles and have a
>>> memory of someone using it on steel. Will that also
>>> seal the copper patina more durably than say
>>> polyurethane  or wax? Just letter openers.
>>>
>>> Lee
>>>
>>>
>>>
>> I use tung oil on steel.  Multiple coats will help but certainly not 
>> as tough polyurethane.  You can wax a tung oil finish.
>>
>> _______________________________________________
>> Manage membership or unsubscribe at:
>> http://mailman.qth.net/mailman/listinfo/theforge
>> theforge mail list group photo site is
>> http://www.photoaccess.com
>> Login:  blacksmithblacksmith at hotmail.com
>> password:  anvil
>> ___________
>>
>>
>>
>
> _______________________________________________
> Manage membership or unsubscribe at:
> http://mailman.qth.net/mailman/listinfo/theforge
> theforge mail list group photo site is
> http://www.photoaccess.com
> Login:  blacksmithblacksmith at hotmail.com
> password:  anvil
> ___________
>
>
>