Clear coating brass, copper and bronze

A. Hi David. Brass lacquer was designed for this purpose, and is used by many high end manufacturers, so one possibility may be that you need a specialty lacquer -- a better one than you previously used.

adv. Maybe G.J. Nikolas [a finishing.com supporting advertiser] can offer you a specific product.

E-coating is another possibility. UV cured coatings can be exceptionally hard, but I don't know if any are suitable for copper and its alloys. I think, but do not know, that merely covering copper doesn't work well; rather, the coating or pretreatment should probably incorporate or be preceded by a preservative like benzotriazole ⇦this on eBay or Amazon [affil links] . Best of luck.

A. There are several water borne coatings for brass, copper and bronze but we would require some additional info such as any other film properties desired, i.e ., weathering or chemical resistance, hardness. Semi Gloss clarity control requires absolute application control to maintain sheen appearance.

A. Dave, there are catalyzed water borne polyurethanes available for your purpose that have been used successfully on brushed aluminum passenger rail cars and other non ferrous substrates. There are some limitations on highly polished surfaces because clear acrylics are slightly opaque and are not water white clear but they do provide an acceptable sheen.

A. On coating with Vitrinite, I don't believe that trichlor will remove a chromate conversion coating. But especially, see J. Hosdowich's field report filed in 1955 on wiping with solvents, see "Barney the Buffer"

  
Tom Pullizzi
Falls Township, Pennsylvania

A. The Brass Bird Sculptures: If G.J. Nikolas [a finishing.com supporting advertiser] doesn't have a better suggestion, you could get a can of clear lacquer from a hardware store. I believe that you would need to start with a clean surface, so I would use a brass polish. I am afraid to offer Barney the Buffer's use of solvent wiping afterwards, but you might test spray a piece of copper to see if and how you should clean the sculpture before painting. On brass plated steel for lamps, you don't design a fixture so the fixture itself is heated to 500 °F? Regards, Tom

A. Hi guys,

I am not talking about the copper or brass pieces exposed to salt water. etc., for but ordinary copper and brass items, if it is not cookware, a good coating of regular, clear hair spray will prevent them from tarnishing for a long time. This will work very well for Pat Mooney's copper and brass Bird sculptures. :)

A. Hi Hollis. Hair spray is formulated to hold hair in place; brass lacquer is formulated to protect brass from corrosion and help retain its polished look. They are very different and, while hair spray certainly might be 'good enough' for some applications sometimes, there can really be no question at all of which is better.

The issue becomes how much brass do you need to lacquer, how well, and how important is trying to save $10 and the inconvenience of ordering the brass lacquer?

I am not making fun of the hair spray suggestion at all! ... I'm just saying that while it may be appropriate for someone who has one old brass knick-knack and a half-used can of hair spray on hand, please don't go out to buy hair spray instead of brass lacquer … that would be very silly. Good luck.

Regards,

A. Chad,

PVD coating on stainless steel might do the trick. I've tested titanium colored stainless in a home oven and found 550 °F (max on a conventional home oven) to be no problem. Color can be gold or light gold (brass).

adv.
My company has a product called Tuffcoat that will clearcoat brass, etc. It is nearly invisible and has survived up to 1300 hours in salt spray. Tuffcoat can be dyed any color.

Incralac
(brass lacquer with benzotriazole)

on eBay or

Amazon

(affil links)

A. My experience with copper sculptures and clear coating these to protect the color patina has been 34 years so far. I can tell you that Rust-o-leum clear seal that is sold today [Rustoleum Crystal Clear [affil links]] is the fast dry formula and is sufficient for 5-8 years, the older formula 1 1/2 hour dry time expect 12- 14 years indoors, but Incralac ⇦this on eBay or Amazon [affil links] ⇨
will survive for 8-10 years outdoors with bi-yearly waxing. The biggest problem with outdoor exposure is the expansion of the copper and the clear coating inability to keep up with this. Failure occurs at 3 years, more or less, with most store-bought sprays. Aircraft coatings in clear are very hard and fail on copper doors at 3-4 years. So the key to finding a good finish a difficult one but not impossible. Fluxes used during brazing WILL break through the finish and should always be removed prior to any coating.

A. I just wanted to add this about finishes. I just received a sculpture into my studio that I made in 1974. It was in for a repair. It had been slightly damaged on one corner and needed straightening. First I cleaned it with warm soapy water and dried it and was really amazed at how well the finish had held up. It had been applied some 35 years ago and it still had great sheen and no crazing. When I first started working in my craft I used Rust-o-leum clear and in fact had used it for about 30 yrs. when the makers of Rust-o-leum changed the formula and it was never the same. Seems they went to a fast dry and to get good coverage it wasn't the finish I needed to use any more so I switched to Incralac ⇦this on eBay or Amazon [affil links] and haven't looked back. The sculpture was indoors for its whole life so far.

A. Try Everbrite [a finishing.com supporting advertiser] coating! Good luck

A. I believe the ultimate in clear coatings for ferrous and non ferrous metals is a product called Permalac [adv: Permalac on eBay]. Its development history includes Incralac ⇦this on eBay or Amazon [affil links] , which is used by major art institutions to protect bronze sculpture. Permalac is made by Peacock Labs and distributed by Sculpt Nouveau [and others].

I am not an agent for either business.

Best,

A. Thanks, Bernard. We're not familiar with that particular brand, but sometimes older brands contained stronger but more dangerous chemicals and they can't offer them anymore. If you are having trouble sourcing a metal lacquer you could speak to G.J. Nikolas [a finishing.com supporting advertiser], who would surely be familiar with what type of lacquer was offered by Sheffield. Good luck!

Regards,

A. Whatever coating is used, acetone ⇦this on eBay or Amazon [affil links] Warning! highly Flammable! will clean the surface of copper nicely prior to clear coating. Incralac ⇦this on eBay or Amazon [affil links] is probably the best for exterior use. Permalac is also good. If you spray the coating, cut it with lacquer thinner ⇦this on eBay or Amazon [affil links] Warning! highly flammable! 3 to 1.

A. Hi Valerie. Automotive 2-K clearcoats are made for almost exactly this purpose and you have the advantage that there are numerous body shops in every locale who can do it for you so there's no experimenting on your professionally applied patina.
Luck & Regards,


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

(To show dark non-relieved areas)
Courtesy: Balfour.com

A. Hi, Gail. I have no jewelry-making experience or aptitude so I can't presume to advise on good practice. But I think that darkening the recesses and relieving the high points makes for a good living finish (picture the ubiquitous high school ring).
If you were to try to do things the opposite way, retaining brightness down in recesses and darkness on the high spots, not only will it not work well, but it will look unnatural anyway -- so maybe the fact that the patina readily wears off isn't wrong.

If the traditional single component clearcoats don't work because you need a more abrasion-resistant coating, maybe a 2-component system like automotive clearcoat would work well.

Regards,

A. I am 5 years into restoration of a 1938 fire truck with a whole boatload of brass. I tried to clear powder the bell after polishing it to a high shine. The heat from the oven destroyed the polish job and profoundly discolored the brass @ about 400 deg. The heat left the metal surface with a "sandblasted" feel to it. The repair was not cheap. I am currently using a clear lacquer that is one of the 3 or 4 top sellers for in/outdoor use on polished brass and I am so far, happy. My advise is: make sure it is lacquer, not an enamel. Enamel stays liquid longer and raises the odds of drips and runs, and tends to turn milky white as it absorbs the moisture (humidity) while it dries. Whichever brand you use, spray it and use a fast thinner so that the lacquer does not turn milky from humidity. I am not a trained professional, just a lot of expensive tuition to the school of hard knocks. I hope this helps, John K.

A. Hi Larry. There is not and never will be such a product :-)
Is a Honda or a Hyundai the "definitive, best there is" car? In fact, since there are waxes, lacquers, one part clearcoats, two-pack clearcoats, epoxies, polyesters, cathodic electrodeposition coatings, UV cured lacquers, physical vapor deposition coatings, preservatives, conversion coatings, etc., … we could ask whether a Porsche or a Peterbilt or a Harley is the "best there is" vehicle. Sorry, but there just isn't any answer to such questions.

It depends on interior/exterior, temperature range, whether UV resistance is important, whether the coating needs to be removable, whether you want to be able to be able to add another layer without stripping, safety oin application, environmental impact, how free of yellowing it needs to be, how much it costs, how quick it cures, and (as you imply) how much work you are willing to put in.

2K Clearcoat

on eBay or

Amazon

(affil links)

High end door hardware "lifetime finishes" are not wax, lacquer, or clear coat at all. The surface you are seeing that looks like brass is not brass (although the handle may be made of brass). What you are seeing is zirconium nitride or a similar ceramic hardcoating which looks like brass but isn't brass, and is applied by the PVD (physical vapor deposition) process in a vacuum on top of nickel electroplating. This requires a very expensive (well over $1M+) machine in addition to the nickel plating.

If you don't want to fire up a compressor and then have to clean out all the lines, but you otherwise like the idea of two-pack clearcoats, they are now available in spray cans with 2-in-1 heads (although it's probably an expensive way to go, and I'm not vouching for rattle cans reliably mixing two-pack chemistry).

Luck and Regards,