Donna:

When you find it, please let me know too.  There is plenty of oral history
among preservationists to indicate that cedar upstream from copper, as in
gutters is bad and that pin holes develop in the gutter...and I have seen this
and have photographs.  I have seen copper stay shiny and not build up the
patina downstream from cedar...and I again I have the photographs.  But, I have
found no learned publication on the subject...and I would very much like too.
I also have been using copper ridge flashings on cedar roofs with a half inch
or so exposed because oral history holds that the run off will kill mold and
moss and such.  Seems to work, I don't think I've documented it.

There's a couple of outfits selling chemical treatments to speed up the
patina.  And there is a contractor in Harrisburg PA who puts lacquier or
something on copper to prevent it from developing a patina.

Hope this helps more than it confuses.

-jc



"Cubberly, Donna R (Donna)" wrote:

> Can someone direct me to documentation regarding a chemical reaction between
> cedar and copper, particularly with regard to cedar facilitating/expediting
> the development of the light green patina on copper?
>
> Thank you.
> Donna R. Cubberly