Replies

1. 
   RickL | Dec 23, 2008 04:14pm | #1

   I assume you mean green patina...

   http://www.bobvila.com/BBS/turning_copper_green__fast-Miscellaneous-1-F1044.html

   What's wrong with google????

1. 
   Carpster | Dec 23, 2008 11:23pm | #4

   What's wrong with google????

   There is a lot of amateur know it alls, this is not the kind of information I am looking for.  I wanted a trusted source of information, that is why I asked here. Thanks

1. 
   RickL | Dec 24, 2008 05:02pm | #6

   As a Metalsmith and purchasing agent I use google as well as my patina library. I find pro-active searches yield quicker and more positive results than asking for sources.

   http://www.jaxchemicals.com/

   http://www.copper.org/resources/properties/protection/green.html

   http://www.sculpture.org/

   http://www.sculptnouveau.com/

2. 
   heartwould | Dec 23, 2008 05:09pm | #2

   One of my sons in law is a contractor who has done some slate as well as tile roofs with copper gutters and flashing, etc.  He has tried several solutions and so-called "products" but he has yet to find anything that gets the "match" to really suit his finicky clients.  Time always seems to do the best job of achieving that beautiful patina.  Please let me know if you find the magic stuff to accomplish your goal!

3. 
   KeithNewton | Dec 23, 2008 05:46pm | #3

   Here is a source for any kind of patina that you can imagine, without having to worry about mixing chemicals that you know nothing about .

   Just click on the online catalog, find patina, then choose the type you want, and each one will give a description of the results on various metals.

   http://www.sculpt.com/

   Although, if you are in a large enough city to have a good stained glass supply store, they will probably have little jars of things like nitric acid, which will do a job on it fairly quick.

   
   

   ---

   Edited 12/23/2008 9:49 am by KeithNewton

4. 
   WillGeorge | Dec 24, 2008 02:08pm | #5

   If you use Nitric Acid

   PLEASE SEE or other data like this.

   http://www.pcl.ox.ac.uk/~hmc/hsci/chemicals/nitric_acid.html

   It is pretty nasty stuff if you do not know how to use it. Like anything.

   Breathing the fumes IS VERY dangerous.

   As to you question, I have no information. My comment is from somebody that was burnt with it long ago. Because it is a highly reactive oxidizing agent I would wonder what happens if dripped onto roofing materials and any other surrounding area.

   Here is how David Marks does it. However he does it before using the copper sheets. I would think that the copper may have poor soldering quality after. Not sure. Maybe mask off the soldering edges, treat the metal and then assemble on the roof?

   http://www.diynetwork.com/diy/ww_chairs_stools_benches/article/0,,DIY_14439_2276538,00.htm

   Maybe ask at Breaktime?

    

   
   

   ---

   Edited 12/24/2008 6:15 am by WillGeorge

5. 
   alias | Dec 24, 2008 07:02pm | #7

   Well here goes........ Urine....... . as Unappealing as it may sound and sophmoric as the presentation maybe . It's cheap and does a surpringingly good job . Try a test piece, after a few beers. I realize how low brow this may come off as , the outcome will surprise you.
6. 
   bigfootnampa | Dec 24, 2008 07:12pm | #8

   Heartwould has given you best advice though... time will do the job better than you possibly could and it works SOOO cheaply too.  Otherwise you are likely to get into a mess that will seem endless and hopeless.  Give good advice and go on to your next job... you'll be incredibly glad that you did.  I am kind of expert on patinas but that's the way I'd handle this.  I have worked for days on matching patinas of a replacement earring before... imagine the scale difference for roofing materials!

7. 
   tomwalz | Dec 24, 2008 08:17pm | #9

   Dear Carpster,

    

   Those are the expert opinions.  In historical renovations they let it age naturally. 

    

   Other wise you can get someone with a very good eye for color and experiment with various patines much like much like paint stripes on a wall.   

    

   What I assume you mean by expert would be a simple, one time process sure to work.

    

   That would involve identifying the existing color and then developing a formula to create it. 

    

   Before you can match it you have to be able to describe the old surface.   The CRC Handbook (see below) list about 130 common inorganic copper compounds.

    

   If the old surface aged naturally it is a result of many years of very complex chemistry. 

    

   If it is Scheele’s green then it is Copper II orthoarsenite hydrogen CuHAs3O(?).  If it is Paris green then it is copper II acetatemetaarsenite Cu(C2H3O2)-3Cu(AsO2)2 (approx).  If there is blue in it then you may have Copper acetate, basic Cu(C2H3O2)2­-H2O.  You will notice that the same chemicals in different configurations give different colors.   This means that you cannot do a simple spectrographic analysis but must go back to quantitative and qualitative analysis. 

   (CRC Handbook of Chemistry and Physics 74th Edition)

    

   Once you are done with the analysis you can design a chemical formula that will create the patine you desire.   However there will be a great enough number of uncertainties that you will want to do some testing first.

    

   Conclusion:

   You have two choices which are to: do as the experts do I historical renovation and let it age naturally or experiment with various chemicals including urine.  If you know much about the history of technology you will realize just how valuable a chemical urine can be in a great number of applications.          

1. 
   Carpster | Dec 24, 2008 08:36pm | #10

   To Tom and Everyone else that replied,

   Thank  you very much! A carpenter I am, a chemist I am not. Although I am persuaded Father Time will do the job best of all.

   I have found the answer I am looking for, which is why I asked here instead of the Google search. I found honest intelligent answers with nothing to buy (except maybe some beer). Thanks again. Carpster

   PS There is some blue in the Patina.

1. 
   nazard | Dec 24, 2008 09:19pm | #11

                  "PS There is some blue in the Patina."

   Carpster,

        Try Blue Moon Ale.  Should do the trick very nicely!

   Merry Christmas!

   -nazard   

    

2. 
   tomwalz | Dec 24, 2008 10:22pm | #13

   The whole patine / patina chemistry is absolutely fascinating.  As you pointed out the colors are wonderfully complex. 

   They restored the train station here in <!----><!----><!---->Tacoma<!---->, <!---->WA<!----><!----> which included a lot of new copper.   There were many complaints that the old copper roof looked so better than the shiny new copper roof.  It took a good deal of work to convince people that the best way was really to let it weather naturally.  Anything else is really likely to shorten the life of the roof and interfere with the color match.

   <!----><!----> <!---->

   It doesn’t take long for it to start changing and a natural patina provides the best protection for the roof. 

   <!----><!----> 

   <!---->Happy holidays to you and yours.  <!---->

   <!----> <!---->

   tom  <!----><!---->

    

8. 
   Woodman41 | Dec 24, 2008 09:19pm | #12

   you won't get a natural looking green patina with anything but time... but a simple method to help copper along is to mix a solution of salt and vinegar and wipe it on.

1. 
   dude | Dec 24, 2008 10:23pm | #14

   our parliament buildings here have copper roofs and the contractor doing repairs to them was rumoured to have used  mares urine

   he had a horse farm near me at the time so there was a good source and possibility it was true

1. 
   Woodman41 | Dec 25, 2008 10:39am | #16

   urine being essentially ammonia and salt... makes sense. Wonder who got stuck with the job of collecting the urine :)

1. 
   WillGeorge | Dec 25, 2008 12:15pm | #17

   Wonder who got stuck with the job of collecting the urine.. If I was the Super.. On that job.. I would make sure every man had a safety belt on and give them all several beers at lunch time!

2. 
   dude | Dec 25, 2008 06:19pm | #18

   if you have ever been near a mare when they urinate you would know it dosent take long to get a bucket full LOL.

   a lot of his employees were from the country so im sure it wouldent have been odd to them to do the job !

2. 
   WillGeorge | Dec 25, 2008 10:36am | #15

   salt and vinegar..

   Thanks for that post. I have used in the past and forgot all about it!

   Sort of like acid rain or by the sea-side...

   I was 'trying' to think of that and it was driving me nuts not recalling it.