Coating to keep copper from tarnishing outdoors

A. Kimberly,
Any mild acid (e.g. citric, acetic) should be able to take the tarnish off, though it won't prevent it from returning! Typically a clear lacquer coating is used for that.

As for creating the tarnish quickly, this is generally known as "aging" or "antiquing" which should narrow down a web search for you, including results on this very site: https://www.finishing.com/07/90.shtml

A. Just keep them cleaned and polished.

Incralac
(brass lacquer plus benzotriazole)

on Amazon or eBay
(affil link)

A. Your advice may be fine for sailors, Simon, but I can't even imagine the level of cleaning and polishing that would be needed to keep bare copper from tarnishing. I'd suggest that the copper needs to receive a benzotriazole anti-tarnish step, then be be lacquered or clear-coated.

Brass lacquer is probably better than polyurethane, Robert.

Optionally you could go with anodized aluminum components which have received a copper colored dye.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

Brass Lacquers

on Amazon or eBay
(affil link)

A. Hi Rose.

All metals with the exception of gold and other precious metals corrode; it's their chemical nature and why you'll find gold nuggets in nature but you'll never find copper nuggets.

Brass lacquer can go a long way towards preventing that corrosion, but must be regularly renewed, especially outdoors, especially in the full sun that a weathervane sees.

Alternately you can let nature take its course and appreciate the beauty of verdigris copper. Good luck.

The beautiful Carousel Building in Asbury Park, NJ

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. Hi Steven.

The old lacquer can be removed with lacquer thinner ⇦ on eBay or Amazon [affil link] Flammable! , the copper buffed back to a shine, the weathervane dipped in benzotriazole, and brass lacquer ⇦ on eBay or Amazon [affil link] reapplied.

If the lacquer doesn't come off with thinner, it's not lacquer but some more exotic clearcoat. In that case, aircraft stripper.
will probably remove the coating without harming the metal, but it's toxic, noxious, dangerous stuff. Use only outdoors, preferably standing up-wind. Wear goggles ⇦ on eBay or Amazon [affil link] and rubber gloves ⇦ on eBay or Amazon [affil link] as a minimum. Good luck.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. Hi Mickey. Sounds like a good coating for that situation, but remember that coatings don't last forever.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. Hi Vikki. We added your question to a previous thread on the subject. Brass lacquer has the advantage over most clear coatings of being easily removable for periodic re-coating ... or in case you change your mind and go for natural aging at some point. Good luck.

Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. Hi again. There is nothing wrong with copper -- it just depends on what you want. Stainless steel may involve somewhat less maintenance. Galvanized is good, but you might not like the look. Nothing wrong with painted or powder coated metal either if you like that look. But the general principle is that it is the nature of all metals (except the precious metals) to tarnish/corrode, so clearcoats offer only a limited ability to deter that problem.

Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. Titanium is the ideal outdoor metal. Can be anodized in many colors and hardly oxidizes, stays shiny, strong as the bonds of friendship. Unfortunately we still aren't producing enough of it to make it accessible, like ... so much so that this is a really unhelpful answer that I just typed, but it's too late now. Aluminum for similar reasons but less so.

Second place is bronze, it will develop a patina but that patina will be so extremely thin that bronze takes years to corrode.

Zinc, another largely unhelpful answer, but so far the cheapest, this is used to coat most steel that needs to be exposed to the elements

Brass. Brass is probably what you want. they make doorknobs and outdoor fixtures. Antimicrobial.

Oh, also stainless steel or anything with enough chromium in it.

Oh and in a certain sense, Gallium. because if it is warm outside it will melt into a shiny puddle and re-solidify at room temp which is objectively awesome.

....sorry, you probably wanted more practical answers but they sent me and I am a year late. Have you considered thorium?

A. Hi Kate. Although people probably won't be able to tell you exactly how long brass lacquer will last, I think at least a year, but probably not much more than two, is a good guess for outside exposure.

Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. As a plumber for over 35 yrs you can always use a course grit cloth for getting back the original sheen; this is required for soldering old pipe but the patina is easily removed if you want to keep it shiny on a regular basis

Zymol Wax

on Amazon or eBay
(affil link)

A. For those looking to keep brass or copper polished and shiny, I have found a very good high quality Auto Wax works well. A good auto wax with high 60-80% Carnauba content (not liquid wax or cheap box store waxes) will last a long time. Car wax ⇦ on eBay or Amazon [affil link] is designed to last through sun UV and a host of environmental conditions as well as protect high quality auto finishes. The wax will eventually wear off, however it should easily last a year or more depending on where the copper or brass is located and what it is exposed to, but not all auto wax is equal. I use a good quality "Zymol" ⇨
wax on my vehicles and also on copper and brass articles as well as a collection of copper bullets with brass casings, it lasts months with handling them occasionally and is easily re-applied.