Green patina

Elaine, Yes, you’re absolutely right. And to prove it, I have metal
lawn furniture outside, one of which (for whatever ungodly reason!)
my two dogs consistently urinate on and it is, indeed, patinated
half-way up the legs! (NO, the guests are NOT offered that chair when
we barbeque - only the tax assessor is!) :wink: -Madeline, Arts Umbrella
Studio

OK this is getting really gross and all, but doesn't urine (of any
animal) have ammonia in it?  And it's the ammonia that is creating
the green patina right? 

G’day. Ok, Elaine; you started this - 'twasn’t me, eh? I can prove
it too. So!. Urine straight from any healthy animal’s body does not
contain Ammonia. Neither does it contain any bacteria - it really
doesn’t. it is completely sterile. BUT; it does contain a large
variety of things which bacteria like; there are all kinds of
nutrients in the stuff, and urea is only one of them; common salt is
another. However, there are always heaps of bacteria in the air and
on everything so it only takes a few seconds for them to find this
valuable fresh food source and begin to raise their families. Urea is
rapidly converted by many types of bacteria to various things and one
end point is ammonia. (OK; there are bugs who like that too, but let’s
not stray too far.) And it is mainly the bacterially generated
ammonia which does your beautiful patination on brasses and bronze.
So it could be more socially acceptable and a lot less yucky to wet
your grease free brass/bronze with salt solution (sodium chloride) and
seal it into a polythene bag with ammonia soaked sawdust. You can
keep it in a warm place and even monitor the progress of the colour(s)
through the almost transparent bag.

Finally, for your greater erudition, allow me to add that the
chemical ‘urea’ was the very first substance hitherto only found with
life, ever to be synthesised in a laboratory. It is now made in the
thousands of tonnes by the petrochemical companies around the world.
What’s it used for? Why, fertilizer, mostly! But also as a feedstock
for making other chemicals. And de-icing roads and aeroplanes. And
there you are; much more than you ever wanted to know about urine.
Blame Elaine, not me! Cheers,

Elaine,

I’m guessing that there are a lot of sources for ammonia these days
that weren’t around in the old horse (urine) and buggy days. I
can tell you (because I know several dozen of these folks) that
recreationists LOVE to use ancient methods to produce authentic
patinas. No doubt some of the green patinas you see were produced
by
time honored methods. If it makes you feel any better I can tell you
that not a bit of ammonia, horse urine or cat urine remains on the
finished product. :slight_smile:

My Dad is a retired Obstetrician, and I happen to recall that some of
the ickier parts of horses were the original source for Premarin.
(Synthetics have long since replaced the equine involvement.) Now
aren’t you glad that you live in the 90’s? (Not that I’m assuming
you’re old enough to have any familiarity with estrogen
supplements…but if at some point in the future you find yourself
swallowing one, you can be assured that horses are no longer
involved.)

Sometimes ignorance truly is bliss.

-Peter-

G’day Elaine; I wrote the following blurb in response to an earlier
posting - I don’t know if it was you or another Elaine - I think
there are at least two with your name. I sent this off a good while
ago and it hasn’t appeared on Orchid yet - I have noticed that I seem
to see replies to my messages quite often before they appear on my
computer! So here you are:–

OK this is getting really gross and all, but doesn't urine (of any
animal) have ammonia in it?  And it's the ammonia that is creating
the green patina right? 

G’day. Ok, Elaine; you started this - 'twasn’t me, eh? I can prove
it too. So!. Urine straight from any healthy animal’s body does not
contain ammonia. Neither does it contain any bacteria - it really
doesn’t. it is completely sterile. BUT; it does contain a large
variety of things which bacteria like; there are all kinds of
nutrients in the stuff, and urea is only one of them; common salt is
another. However, there are always heaps of bacteria in the air and
on everything so it only takes a few seconds for them to find this
valuable fresh food source and begin to raise their families. Urea is
a large constituent of urine, and is rapidly converted by many
types of bacteria to various things, and one end point is ammonia.
(OK; there are bugs who like that too, but let’s not stray too far.)
And it is mainly the bacterially generated ammonia which does your
beautiful patination on brasses and bronze. So it could be more
socially acceptable and a lot less yucky to wet your grease free
brass/bronze with salt solution (sodium chloride) and seal it into a
polythene bag with ammonia soaked sawdust. You can keep it in a warm
place and even monitor the progress of the colour(s) through the
almost transparent bag.

Finally, for your greater erudition, allow me to add that the
chemical ‘urea’ was the very first substance hitherto only found with
life, ever to be synthesised in a laboratory. It is now made in the
thousands of tonnes by the petrochemical companies around the world.
What’s it used for? Why, fertilizer, mostly! But also as a feedstock
for making other chemicals. And de-icing roads and aeroplanes. And
there you are; much more than you ever wanted to know about urine.
Blame Elaine, not me! Cheers,

Now you can go an have a nice good puke, Elaine. Cheers,

        /\      John Burgess
       / /
      / /      Johnb@ts.co.nz    
     / /__|\
    (_______)   It's spring in Mapua Nelson NZ And rains mostly

at night

There’s a good description of how to do the “sawdust patina” in an
article on patination by Claire Sanford in the book, Metals
Technic
, edited by Tim McCreight (Brynmorgen Press, Cape Elizabeth,
ME; 1992), pp. 124-125. The rest of the book is good, too!

Judy Bjorkman
@JLBjorkman

Good Morning, Mr. Burgess…

Urea also is used as an activation agent when dying fabric… thought
this might be a good way to tie together both your posts. Another
way to think of the difference between “painting” and “dyeing” is
that a dye will attach (more or less securely) to the molecular
structure of the fiber (or polymer) and paint will only “sit” on top.
I have absolutely no significant knowledge about chemistry, but my
hands are stained with dye and… uh… there is paint in my new
carpet courtesy of my three rugrats. Must qualify me for
something… Mia

To all fans of green patina:

THIS IS NOT A LIE. ( I borrow the expression from Dave Barry.)

My brother is a sculptor who makes large works, most often with
copper. When a piece is finished he puts it out in the yard (he lives
on Cape Cod in Massachusetts), buys lots of beer and invites all his
friends over. Male friends. You can probably figure the rest out.

I have one of his pieces hanging on the front of my house (yes,
outside).

Ann Dalrymple
@agd

   I believe the formulas were from that 'Patination...' book from
England, sorry I don't have the name and authors handy right now. I
hope this will inspire some of you to try it. 

Dear Lorri et al. The book you are referring to is probably The
Colouring, Bronzing and Patination of Metals
by Richard Hughes and
Michael Rowe, Thames and Hudson Ltd. London, ISBN 0-500-01501-5. It
gives you 228 recipes for Copper and a varying number of recipees for
cast bronze, cast yellow brass, gilding metal (whatever it is), sheet
yellow brass, and silver.

Glad, if I could be of any help here.

Kind regards from autumn Denmark
Niels Loevschal, Jyllinge, Denmark

John, Do the appearance of the replys to your messages before you
write them have anything to do with the fact that you are a day ahead
of us or something like that? Now theres a question to ponder.

Peter, Your just going to hate this, but the real stuff is alive and
well. I was just prescribed it. but never used the prescription. I was
told my Dr. that the synthetics out there do not work as well. Horses
are still very much involved. Check out the PETA website involving
Horses. Susan

My Dad is a retired Obstetrician, and I happen to recall that some of
the ickier parts of horses were the original source for Premarin. 
(Synthetics have long since replaced the equine involvement.) 

Actually Premarin is still made from pregnant mare’s urine (that’s
how the name was derived, PREgnant MARe urINe). The synthetics have
different names. If anyone wants URLs for pages with info on the
subject email me privately since it’s very off topic.

Lynn A. Davis
Tephra’s Treasures
Handcrafted Jewelry, Accessories
And Other Fine Treasures

I thought all you “green patina” folks would like to know that Martha
Stewart (yes, The Martha Stewart!) says that all you need to do is
spray your copper with vinegar. Frances

Visit me or “beam me up” at:
http://members.toast.net/frangro//index.html

You should probably know that copper patina is highly toxic. Thats
why tinsmiths from the middle ages used to coat the inside of copper
vessels with tin. Geo.