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Oil patina on silver


#1

Was: Best metalsmithing book

Marlin: this sounds great - do you just "paint" on the peanut oil
in a thin coat and then torch it? Does it "flame" up like boric
acid/borax/alcohol mix? Or does it just "melt" into the copper and
harden? Is there some way to tell when you have "torched" it
enough? Or is it a matter of the color you are seeking? I'm anxious
to try this. Also....does it come off if put in pickle?  I'm
thinking of using it with some marriage of metals I have but if I
flame it with the torch, then the silver/nickel portions of the
piece also turn or can you paint the silver portions with boric
acid mix and the copper with peanut oil and then torch it? And
lastly how "permanent" is it? If it turns to "varnish" as you say,
then it seems it would be fairly permanent. How do you remove it
if you don't like it? Anxious to hear as I want to try it this
week. 

I had another offline inquiry into the use of peanut oil to patina
copper. To clarify the little that I know I submit the following In
searching the Orchid archives, I found this 10 year old post

https://orchid.ganoksin.com/t/urned-oil-patina-on-silver

which is basically the same as what I do on a much larger scale. I
use a bushy yellow reducing flame. I just tried a small butane/air
torch without much air and it worked much better than my Oxy/pr=opane
or acetylene torches. The way I do it is to wipe a thin film onwith a
cotton q-tip dampened with a bit of oil, heat until it barely smokes
pull it from the flame and q-tip it again - sometimes I will q-tip
one side while heating the other side - generally catching the q-tip
on fire. It behaves as you would expect an over heated oil in a
skillet to behave. Keep doing this until you get the finish you need.
Other oils may work better - walnut, flax (linseed), canola or
perhaps some oil fine art painters use. You can also see some neat
iridescent type colors similar to western raku fired pottery. These
colors may be impermanent, I do not know.

It is difficult to precisely control, and I doubt that you would be
happy with a mixed metal piece, it would likely dull the silver way
too much. I have never tested the durability, but assume it
approaches the durability of varnish. I would also compare it to the
process of curing a cast iron skillet in the oven, and would guess
that if you have a casting oven or even a high temp toaster oven you
could get more controllable and repeatable results.

As for removing this finish, a hot enough oxidizing flame followed by
pickle would work, I bet a paint stripper would also do a reasonable
job. Remember though, that you have heated and oxidized the
underlying metal as well, so when you remove the finish, the metal
will most like have a oxide coating unless you pickle it.

An interesting note about copper and oil. When I anneal copper, I
will sometimes cool it in oil. When the red hot copper hits the oil,
it acts like a reducing agent and partially cleans the nasty black
oxides from the copper, sometimes leaving the nice deep red oxides
behind.

Again, I urge you to read Peter’s 1999 article as well. I am no
expert on this technique, just a fan of playing with fire and metal.

Marlin


#2

Dear All,

Does anyone know if other oils can be used to make the patina on
copper, for example corn oil or sesame oil?

Sharron in still hot Dhaka dreaming of working in the studio with no air-
con soon.


#3
Does anyone know if other oils can be used to make the patina on
copper, for example corn oil or sesame oil? 

Not exactly oil but you can get some really wild patinas on copper
using urine soaked sawdust from horse stalls. I’m sure you can get
as much as you need from anyone who stables horses…

Rick Copeland
Silversmith and Lapidary Artisan
rockymountainwonders.com


#4
Does anyone know if other oils can be used to make the patina on
copper, for example corn oil or sesame oil? 

To make a good sealer, you need a drying oil (again see the
Wikipedia article on ‘Drying Oil’). Examples of drying oils aRe:
linseed oil, tung oil, poppy seed oil, perilla oil, and walnut oil.

Corn or Maize Oil… has very little, if any, drying properties, and
will harden to a brittle, rather mealy film in from twenty to thirty
days (from “Paint Making And Color Grinding”, by Charles L. Uebele)

I am not sure about sesame oil, b ut you can try and let us know.

One hint that an oil is a drying oil is the dried or congealed oil
scum that forms on the spout on some oils (this is the "drying"
effect), at least it forms on my old walnut oil bottle. Much less so
on my olive oils and peanut oil.

Marlin, who is by no means an oil expert, in warm Denver


#5
Not exactly oil but you can get some really wild patinas on copper
using urine soaked sawdust from horse stalls. I'm sure you can get
as much as you need from anyone who stables horses.. 

Textures and shapes too, if instead of extracting the sawdust from
the stalls, you bury your work in it, “in situ”. The horse pees on
it, and tramples it too. Think of all the metal moving effort you
save by letting the horses hooves do the work for you… (grin)

Reminds me of an odd story told at Cranbrook art acadamy when I was
there in the 70s, about students who’d been there some years before.
Seems they were investigating some patinas, especially Rokusho, and
other Japanese patinas (and as well, the peanut oil finish, which
apparently has a long tradition behind it, unless Richard Thomas made
that part up and was, himself, the tradition. Not sure. but
anyway…) Seems a vital ingredient of one patina being investigated
at the workshop was urine. In order to obtain the required
quantities, the participants were enjoying copious amounts of beer,
with predictable results on vertical stability of the metalworkers…
Sounded like it was a fun workshop.

Not sure if I should put my name on this post…

“Pierre.”


#6
Not exactly oil but you can get some really wild patinas on copper
using urine soaked sawdust from horse stalls. 

I wonder if a cat’s litter box would work as well.

Mike DeBurgh, GJG
Henderson, NV


#7
...you can get some really wild patinas on copper using urine
soaked sawdust from horse stalls... 

Rick, is that patination done cold rather than using heat as
described with the oil patina?


#8
Not exactly oil but you can get some really wild patinas on copper
using urine soaked sawdust from horse stalls. I'm sure you can get
as much as you need from anyone who stables horses... 

Ha! This reminds me of how counterfeteirs age silver, copper and
bronze objects to give them that centuries old look. Mix cow or horse
manure and urine with straw and dirt. Put in a jar together with the
object/s to be patinated and close with the lid. Bury underground in
a sunny spot and leave there for 1 to 3 months. This gives a very
convincing antique patina.


#9
Seems a vital ingredient of one patina being investigated at the
workshop was urine. In order to obtain the required quantities, the
participants were enjoying copious amounts of beer,... 

Funny, years ago I read the same story for a procedure in a mokume
gane workshop. I must not be attending the right workshops.

Lois


#10

Mikw; The litter box method is a tried and true patina method. Just
bury the metal in the litter box and check it from time to time.

Dave Owen


#11

I would recommend heat. The last time I tried I put a piece of
copper sheet in a zip lock bag covered with horse urine soaked saw
dust. I checked it every couple days then I forgot about it. I have a
short attention span. The colors were pretty wild greens and blues
then the last time I clean up the shop I found the bag and emptied it
out and had an ugly brownish black piece of copper which went into
the recycle bin.

I suppose you could do the same and put the bag out in the sun to
speed up the process…

I never followed up on it because I don’t usually produce copper
jewelry and didn’t want to get into coating the copper to maintain
the patina. Plus my cousin, the horse woman, moved so I don’t have a
ready source for urine soaked sawdust and going door to door to the
local ranches enquiring if I could have some horse urine soaked
sawdust might get me run off at the point of a gun or lead to a
whole lot of work cleaning stables. Both situations I would find
distasteful.

Rick Copeland
Silversmith and Lapidary Artisan
rockymountainwonders.com


#12
I wonder if a cat's litter box would work as well. 

That’s what we were told to use at a community college course I
took. Even more fun than the patina are the looks you get when you
ask friends for used kitty litter, if you are not presently owned by
a cat.

Going off thread here, but I got a fabulous blue patina on silver by
fusing bench dust and scraps to a piece of silver then “fuming” it
with ammonia (suspending in closed container over ammonia). Once it
turned blue, I realized some of the bench dust was copper, some
gold-fill - unexpected but pretty.

It’s on my website under Blog, Baby!


#13

If you spray or paint a 1:1 Miracle Grow and water solution on a
piece, it will turn a beautiful turquoise within 24 hours. You can
control this, so I do things with stickers and tape and then have the
copper designs show through the patina.


#14

The talk of using urine to quickly add a finish to copper reminds me
of a talk I once had with my stepfather. He’d been a pilot for many
years and told me of a short article he’d written for an aviation
magazine regarding hydraulic systems in small aircraft in which he
said if the landing gear won’t operate because it’s lost fluid, in a
pinch Milspec U-R-INE will work long enough to enable a landing.

Apparently its good for more than just relief at the end of a long
drive.

Mike DeBurgh, GJG
Henderson, NV


#15
If you spray or paint a 1:1 Miracle Grow and water solution on a
piece, it will turn a beautiful turquoise within 24 hours. You can
control this, so I do things with stickers and tape and then have
the copper designs show through the patina. 

Sounds like simple enough procedure. Some questions: - Does it get
deeper color with more spraying or painting on of Miracle Grow
solution? And most importantly, how permanent is this? Can it be
sprayed (or painted) with lacquer to keep it in top shape? And does
it eventually fade or darken with age? And does the article need to
be hot first? Does heat affect the outcome? Will definitely have to
try this.

Bericho


#16
If you spray or paint a 1:1 Miracle Grow and water solution on a
piece, it will turn a beautiful turquoise within 24 hours. You can
control this, so I do things with stickers and tape and then have
the copper designs show through the patina.

What is and where to get: Miracle Grow?

Peter D
New Zealand


#17

I may be wrong, but I believe that the main ingredient in Miracle
Grow is good old Ammonium sulfate, found at any garden supply place
or nursery. I use it regularly in my garden. Alma


#18
What is and where to get: Miracle Grow? 

It’s a water soluble plant food from Scotts Company. In the US, you
can get it at any garden supply, even the grocery.

Ingredients from MSDS/Label
Chemical CAS No / Unique ID Percent
Urea 000057-13-6
Urea phosphate 004861-19-2
Potassium chloride 007447-40-7
Sodium molybdate 007631-95-0
Ammonium phosphate, monobasic 007722-76-1
Zinc sulfate 007733-02-0
Copper sulfate 007758-98-7
Chlorine 007782-50-5
Boric acid 010043-35-3
Manganese EDTA, disodium salt 015375-84-5
Ferric sodium EDTA 015708-41-5

Al Balmer
Sun City, AZ


#19

I use a generic flower fertilizer. It is blue when mixed. You do not
need to heat the copper, just make sure it is clean. After, seal
with a sealer.

I have a couple of examples in my shop, beadlesandstones.etsy.com

Debbie