Cat litter patina?

Jewelry Discussion
1

People always tell me cat pee is a great patina, and I finally tried
it. I did two tests, one copper covered with litter, and one copper
suspended over litter. The suspended one came out a beautiful dark
teal blue, but I have to admit I am a bit grossed out by the source.
Is it essentially amonia that is doing the coloring? Is it going
to stink or bother people’s skin anymore than any other patina? (I
am going to seal it with wax) suggestions? comments? experiences?
Tracey - in New Mexico with too much spare time on her hands and
some confused cats.

2

hi tracey, Ammonia in sawdust, or a small container of it sealed in
a plastic bag with the copper item will give you the same ( or
similar) patina, without upsetting the cats :wink:

3

In ancient times horse urine as well as human were used to achieve
patina on copper. . However, there is no need to resort to either of
those sources, or to raid the liter box. Just plain amonia
drenched sawdust, or amonia sprinkled in fresh cat liter will do the
job, and will probably be more sanitary. There was a thread on this
some time ago, so check the archives. Alma

4 
 Ammonia in sawdust, or a small container of it sealed in a
plastic bag with the copper item will give you the same ( or
similar) patina, without upsetting the cats ;-)

G’day; As Christine implied,. it is the ammonia and primary
amines in stale urine which cause the patina reaction. These
substances are produced by bacterial attack on various substances
in the urine; fresh urine is completely sterile unless the producer
has a virus which can get through membranes that bacteria in the
body cannot. Urine is a really excellent culture medium for many
bacteria.

Here’s a couple more suggetions;

  1. Dampen - not soak - a small piece of sponge with undiluted
    household ammonia (from the supermarket) and place it in a sealed
    plastic bag with the object to be patinated which must be clean and
    grease free. If it is firstly wiped over with a solution of copper
    sulphate or very blue old pickle, and allowed to dry the patination
    will be more rapid.

  2. Obtain some solid pieces of ammonium carbonate (your local
    pharmacist?) and use that instead of the sponge - less messy.
    Ammonium carbonate is used in smelling salts., and gives off ammonia
    . I don’t think normally fastidious people want to muck about with
    bodily wastes when there are good alternatives available.

Cheers for now,
John Burgess; @John_Burgess2 of Mapua, Nelson NZ

5

Reflecting on John Burgess’s statement about mucking about with
bodily wastes, well, that’s considered performance art in some
circles, and gets government subsidies.

Personally, I’d rather be coerced to spend on Fulbright scholars
studying jewelry and sculpture in balmy tropical lands. On the
flipside, they’re my customers.

Dan Woodard