Working with Copper
 

I hope some knowledgable people out there can give me some advice!

I'm intending to use copper microbore (8mm & 10mm) to make a "twisting" garden sculpture. I'd like to know what colour this will end up when left outside, as I don't know whether microbore is "annealed" or "enamelled" or not treated at all.

I may also incorporate some smaller wire for decoration - I'm considering Enamelled Copper Wire (2mm) which I assume would stay "shiny" even outside? Or possibly annealed copper wire (like that used for binding bonsai trees!) - I believe the latter would end up a dull sort of brown colour - am I right? (probably not!!)

Many thanks in advance of any kindly forthcoming help...

In message ,
writes

I hope some knowledgable people out there can give me some advice!

I'm intending to use copper microbore (8mm & 10mm) to make a "twisting"
garden sculpture.


You mean a still ?


--
geoff

raden wrote:
In message ,
writes

I hope some knowledgable people out there can give me some advice!

I'm intending to use copper microbore (8mm & 10mm) to make a "twisting"
garden sculpture.


You mean a still ?

If it was a still, he wouldn't be working with copper.
Unless it was bent copper.

In message , Ian
Stirling writes
raden wrote:
In message ,
writes

I hope some knowledgable people out there can give me some advice!

I'm intending to use copper microbore (8mm & 10mm) to make a "twisting"
garden sculpture.


You mean a still ?

If it was a still, he wouldn't be working with copper.
Unless it was bent copper.

"Twisting" seems to indicate something other than straight lines Ian

I've heard that they have such things up in Scotland

--
geoff

wrote in message
oups.com...
Or possibly annealed copper wire (like that used
for binding bonsai trees!) - I believe the latter would end up a dull
sort of brown colour - am I right? (probably not!!)

green


Properly annealed metals should retain their annealed appearance almost
indefinitely.





a

I tend to think they put some laquer on the pipe at production to keep
it shiny. I do outdoor sculpture with copper and first use fine steel
wool to get down to bare metal, chemically clean with good old malt
vinegar (how people use that stuff as food flavouring !) and then with
a bit of practice apply a cupric nitrate solution. Hey presto 3 years
worth of patination in an hour. If you want to keep it a plain old
brown just apply some wax to keep the acid rain away.

David wrote:

I tend to think they put some laquer on the pipe at production to keep
it shiny. I do outdoor sculpture with copper and first use fine steel
wool to get down to bare metal, chemically clean with good old malt
vinegar (how people use that stuff as food flavouring !) and then with
a bit of practice apply a cupric nitrate solution. Hey presto 3 years
worth of patination in an hour. If you want to keep it a plain old
brown just apply some wax to keep the acid rain away.


What is the stuff that make it stink of rotten eggs and turns it black?
Presumably a sulphite of some sort?

OI had mnoe of those 'copper picture' kits years ago. A layer of laquer
has kept if a good mixture of copper and black for years...

What is the stuff that make it stink of rotten eggs and turns it black?
Presumably a sulphite of some sort?

Hydrogen Sulphide.

On Fri, 08 Apr 2005 07:27:24 GMT, "al"
wrote:

Properly annealed metals should retain their annealed appearance almost
indefinitely.

What's an "annealed appearance" ?

Annealed pure copper will remain soft indefinitely, but most aluminium
alloys will "age harden" afterwards, no matter what you do. This is
inherent in the alloy's behaviour, it's not a question of "proper
technique"


Copper left alone outside will darken to a tolerable dark patina, but
it will take an age and is likely to have pale green spots on it.
You're unlikely to get a greenish deposit overall, unless there's
water or tree sap running over it, but you'll get at least one visible
splodge of it. To avoid this, apply a deliberate patina immediately.
Applied patina is more stable against discolouration than bare metal.

For an easy life, spend a fiver on a bottle of Liberon's "Tourmaline
brown" antique patina for copper (from Axminster). It's an easy cold
process - not the best in the world, but it's the best you can do for
a fiver, working cold, and without shopping for awkward to locate
chemistry.

If you want to colour copper, then read these two books:

"The Colouring, Bronzing and Patination of Metals"
http://www.amazon.co.uk/exec/obidos/ASIN/0500015015/codesmiths
This is _the_ book on colouring non-ferrous, non-exotics. Expensive,
but worth it. Well known, so any decent library should have access to
it.

Tim McCreight, "Color on Metal"
http://www.amazon.co.uk/exec/obidos/ASIN/1893164063/codesmiths
Cheaper, but less comprehensive. Worth reading if you happen across
it.


Two relatively simple copper recipes with easily obtained ingredients
are these:

Glossy dark brown (recipe 3.69 in CB&P)

copper carbonate 125g
..880 ammonia 250cm^3
water 750cm^3

(It may be easier to replace both water and ammonia with 1litre of 26%
ammonia, which is commonly available in hardware shops)

Simmer in a warm bath of this mixture at 50°C for around an hour - the
colour develops slowly. Wash in hot water, then dry by tumbling in a
box of sawdust . Wax afterwards.



Matt dark brown (recipe 3.70 in CB&P)

cooper sulphate 125g
ferrous sulphate 100g
glacial acetic acid 6.5cm^3
water 1litre

Boil for 30-40 minutes. Wash in hot water, then dry by tumbling in a
box of sawdust . Wax afterwards.


Both of these recipes use common chemistry that's of little toxic
hazard. However the ammonia process needs good ventilation and keeping
away from aluminium (For comfort I wear a full-face mask too - a half
mask is useless, as ammonia will enter via the eyes). Acetic acid in
this strength is corrosive and irritating, so wear gloves and keep it
out of the eyes.

--
Smert' spamionam

"Andy Dingley" wrote in message
...
On Fri, 08 Apr 2005 07:27:24 GMT, "al"
wrote:

Properly annealed metals should retain their annealed appearance almost
indefinitely.

What's an "annealed appearance" ?

I'm glad you asked that, I was wondering too ...

Mary

David wrote:
I tend to think they put some laquer on the pipe at production to keep
it shiny

Really?

"David" wrote in message roups.com...
I tend to think they put some laquer on the pipe at production to keep
it shiny. I do outdoor sculpture with copper and first use fine steel
wool to get down to bare metal, chemically clean with good old malt
vinegar (how people use that stuff as food flavouring !) and then with
a bit of practice apply a cupric nitrate solution. Hey presto 3 years
worth of patination in an hour. If you want to keep it a plain old
brown just apply some wax to keep the acid rain away.

I'm just wondering what colour it would go in salt water. All the
copper exposed to the sea that I've seen is green.
M.K.

Mary Fisher wrote:
What is the stuff that make it stink of rotten eggs and turns it black?
Presumably a sulphite of some sort?


Hydrogen Sulphide.


No, thats what it gives OFF,when applied to teh coppeer... but thats not
waht the stuff IS.

markzoom wrote:

"David" wrote in message roups.com...

I tend to think they put some laquer on the pipe at production to keep
it shiny. I do outdoor sculpture with copper and first use fine steel
wool to get down to bare metal, chemically clean with good old malt
vinegar (how people use that stuff as food flavouring !) and then with
a bit of practice apply a cupric nitrate solution. Hey presto 3 years
worth of patination in an hour. If you want to keep it a plain old
brown just apply some wax to keep the acid rain away.


I'm just wondering what colour it would go in salt water. All the
copper exposed to the sea that I've seen is green.

You are right.

I suspect that is anoher reaction route again.

But copper UNDER teh sea does not...IIRC. It needs air...



M.K.

Well - thank you everyone for so many very informative & interesting replies & ideas. A huge help to me...

I'm not too keen on using chemicals, so will probably start by letting nature takes its course with the finished sculpture, as an experiment! It will be under a tree, so it could get interesting!

The salt water idea appeals if I decide that green would be better than whatever occurs naturally - the thing should be moveable, so I could "douse" it away from any plants that may not be so keen on a salty soaking!

Again thank you all. It's so wonderful that people are so willing & generous with the sharing of knowledge. I don't know what life would be like now without the internet & forums such as this...

Kindest regards!

Chip

Chris Bacon wrote:
David wrote:
I tend to think they put some laquer on the pipe at production to
keep it shiny

Really?

Sorry, David, I've just had one of my infrequent looks at my
e-mail, and I see a comment, so I re-open this to answer -
outbound mail is currently TU.

To expand on my "Really?": they don't put lacquer on copper pipes
to keep them shiny - it would seriously interfere with soldering,
so tradesmen/DIYers around the country would go purple with rage!

Regards,