How to patina Copper? archived

Oooh Lars showed us how at the ornament party. It involves vinegar and salt if I recall....LARS!

Wow - great!

Lars? You there?

Thanks!!!

I remember:

Clean the piece well with soap and water. Coat with salt and vinegar and suspend over an ammonia bath (in a closed container) until the desired amount of patina is reached. You can put the ammonia in a separate container so it's not sloshing all over the bottom of the container--it's the fumes that do the work (and boy are they fume-y).

Copper and Brass Finish Treatments

CAUTION SHOULD BE EXERCISED WHEN HANDLING AND APPLYING PATINA SOLUTION - WEAR GLOVES AND SAFETY GLASSES. FOLLOW SAFETY INSTRUCTIONS CAREFULLY ON THE CONTAINERS.

Spread newspaper under plant material to protect it. It is best to install pathlight fixtures first then apply solution. Fixtures should be clean of oil and dirt with Windex-type cleaner.
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Green Patina Formula
Darkening Copper & Brass
Polishing Copper & Brass


Green Patina Formula:

2 parts
white vinegar
1 1/2 parts
non-detergent ammonia

1/2 part
non-iodized salt


Application:
Clean fixture with Windex-type cleaner.

Premix patina solution in Windex-type spray bottle
Spray Windex cleaner on fixture to break surface tension, leaving it on when you apply patina solution.
Apply patina solution by spraying onto fixture, preferably in the early evening on a high humidity night.
Allow to set for 1 hour, then reapply solution observing where you missed applying on the first coat. If there seems to be oil that is repelling the patina solution, clean it off with the Windex cleaner.
Allow to sit overnight. In low humidity desert areas, use a plastic bag to create a tent over fixture (without making contact with it) to help keep the humidity high during curing. If there is low moisture in the air, the solution will dry out without creating the patina effect.
The result will be a bright green powdery patina. Do not rub off. In time (and re-applications) this finish will become permanent. The brightness will fade with time. To reduce green, cut back on the salt content. Color and effect is greatly affected by application ambient temperature and humidity.
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Hi Rufus -

So let me see if I understand using measurements.

If I use:

2 cups white vinegar
1 1/2 cups non-detergent ammonia
1/2 cup non-iodized salt (I guess I can get this in the grocery store?)

Mix this all together and put in a spray bottle.

Spray the copper with windex and then spray with patina solution. Allow to set for an hour and reapply where necessary. Allow to sit overnight - I think I can do this in my garage and keep there overnight - it's humid enough outside.

Marylago - Thanks as well.

I would like to see what Lars says.

brookh,

That is Lars "recipe." She taught it to me.

ml

When I used to work with stained glass, there was a solution you could buy at an art supply store to give the copper foil or lead solder an aged patina. If I remember, there were a few variations on the eventual finish. If you don't want to make your own, you could buy that. It was applied with a brush, left on for a while and then the piece was washed in warm water and mild soap.

Thanks Cody - I just sent an email to Jerry's Art Supply to see if they have this.