Polished Copper, Brass, and Bronze

[fredrosse]

I like polished Copper, Brass, and Bronze on the steamboat, but I am getting tired of the work it requires. A few questions:

Is it OK to clear coat various low temp pieces, and if so what is the best coating to use?

Has anyone had direct experience with the UV resisting clear epoxies here, and if so how well do they perform?

Copper steam exhaust piping, 212F (100C) maximum temperature, what can be used to clear coat this piping?

Is coating of polished metals going to make for problems of some sort?

Thanks in advance for replies.

[Mike Rometer]

In my experience, copper (and its alloys), when lacquered, tend to get chipped, or worn, and then the tarnish creeps under the remaining lacquer making it look much worse; and much, much, harder to remove. Change the polish that you use, some seem to leave a much longer lasting finish than others.

I use one which is really for auto chrome, called Autosol, but there may well be better ones than that.

[mtnman]

Polishing and painting, isn't that what deck hands are for? Not a job for the Capitan!

[Lopez Mike]

I have had fairly good luck with clear lacquer. After polishing and wiping down with lacquer thinner, I spray coat the polished surface. Not all lacquers can be removed with lacquer thinner. A quick test is to spray something, let it cure for a few days and see if the thinner will dissolve it.

One one hand, it does make for less work in the short run but, as noted, it does fail in a relatively ugly way. Spots and peeling and all that. The up side is that since you have used lacquer, you can remove it with lacquer thinner. Then polish up the discolored spots and re-coat.

It will not work well for things that get hot. I do this with the clock and barometer in my sailboat and it lasts for several years. Out in the sun? Hmmm. I've kept the brass on Folly down to the whistle, the rim of the steam gauge and I'm thinking about a band around the top of the stack.

As usual, no free lunch. A guy brought in a bell that he had coated with epoxy! Had to take a torch to it.

Mike

[fredrosse]

Put in new gas piping, relocated the "Safety Manometer", and polished the main engine overboard exhaust pipe, plus the bilge eductor pipe. The eductor pipe could have discharged much lower, but then I would have had to put a hole in the hull, there are presently none, and I want to keep it that way.

The close-up shows piping in this rather crowded area including the main propane regulator valve, with 1/4 inch copper tubing to the burners, 1/4 inch copper propane from the burner manifold to the manometer, 1/2 inch copper eductor overboard discharge, with 1/4 inch copper tubing for steam to the eductor, feedwater pumps suction and recirculation/relief piping, and 1 inch copper main engine exhaust.

I put clearcoat on the eductor piping as well as the Manometer Pots, the main exhaust piping is just polished with no coating, because this runs hottest of the
lot.

[Bob Cleek]

I'd say trying to keep copper and bronze polished in the marine environment is a pretty daunting task. Brass is another thing. Traditionally, brass is polished aboard, while other metals are not. Bronze will develop a nice shiny brown patina if left to its own. Polishing copper only removes the patina, leaving it open to much faster oxidation. (A light wipe with oil will keep copper from going "green." It will then develop a brown patina, similar to bronze.

After polishing marine brass for over forty years, all I can say about lacquering it is "Please don't go there." Any of the lacquers that last at all are impossible to remove short of very fine sanding and polishing out the scratches on a buffing wheel. Getting it out of crevices and such is often near impossible. Trust me, I've tried every lacquer thinner, paint remove, etching acid and whatever. Lacquer will last very well on a lamp base in a living room. Put that same lacquered lamp in, say, the bathroom, and the moisture will turn it into a gross "poxed" thing in no time. (If you have ever had those very expensive lacquered brass plumbing fixtures in your bathroom, you'll know what I'm talking about.)

Bare brass can be kept polished with any of the quality brass polishes. (I often use "nev-r-dull" polishing wadding to apply "Brasso." "Belt and suspenders," perhaps, but it works well when the polishing routine has been neglected for a time and needs a lot of elbow grease. The trick to keeping polished brass looking top notch is frequent routine polishing. This sounds worse than it really is. Once a piece is really well polished, all it takes is a "once over" with polish and a light buffing once a week or so to keep it looking perfect. If you let it go, and it gets ahead of you, bringing it back up bright will take a lot more work than just a "wipe on - wipe off" weekly.

For those purists who are interested in such things (such as judges at concours d' elegance) there is no way to replicate the "patina" of hand polished brass. The little nooks and crannies, such as around round headed screws or hinges on lamps and clock and barometer cases will not polish up as brightly as the rest of the piece because you really just can't get to them. That subtle contrast is the mark of traditionally maintained quality brass fittings. Lacquered brass looks like, well... lacquered brass. Once the two are compared, the difference is readily apparent and the lacquered stuff looks, well, ... second class.

Your mileage may differ, though...