John:  Thanks for your reply.

It is difficult to believe that there is no documentation on this subject
since it seems that it would be easy enough to prove or disprove by
performing chemical analyses.  As a matter of fact, I have a friend who is
about to begin a master's degree program in chemistry and I have begun
urging her to undertake the task.

Thanks again.
Donna

> ----------
> From:         John Callan[SMTP:[log in to unmask]]
> Reply To:     [log in to unmask]
> Sent:         Monday, April 30, 2001 1:03 PM
> To:   [log in to unmask]
> Subject:      Re: Cedar and Copper
>
> 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
>