Polishing Brass

NCHappyDaddy

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Feb 19, 2021
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Is it considered acceptable to polish or brighten the brass pendulum on a clock? I have a ~1890’s wall clock with a great big tarnished smooth pendulum and think it would polish up nicely to really make the clock pop. But, I don’t want to “destroy the patina” as they say on Antiques Roadshow.

If so, what would you recommend I use and should I coat the brightened brass when finished?
 

bikerclockguy

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Jul 22, 2017
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Don’t use Brasso, as that will strip the lacquer off of the bob. I use Renaissance Wax, but it’s expensive and not readily available in a lot of places. Both Rockler and Woodcraft stores carry it, if you happen to be close to one of those. I have a friend who is a saxophone player, and he uses Mother’s Mag Wheel polish and swears by it. but I’ve never tried that one myself
 

bikerclockguy

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As for polishing and the patina, it might diminish the value somewhat for a hardcore collector, but if you are going to keep the clock and want a polished pendulum, go for it. I like the “original” look to a point, but I don’t care for dull brass, stained dials, etc, and on clocks that have that, I usually go for the restored look. Unless you are selling one, I’d say do whatever makes you happy.
 
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zedric

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Aug 8, 2012
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Don’t use Brasso, as that will strip the lacquer off of the bob.
I’m confused by this. How can you remove the tarnish, which is presumably beneath any varnish, without stripping the lacquer off first?
 
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tracerjack

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I’m confused by this. How can you remove the tarnish, which is presumably beneath any varnish, without stripping the lacquer off first?
Since lacquer prevents tarnish, if the brass is tarnished, then the lacquer is long gone. Care needs to be taken with Brasso. Brasso is harsh and any residue left can cause damage to the brass. I only use Brasso if I can wash the part. Flitz and Simichrome are better for polishing brass and don’t need to be washed off.
 

Mike Phelan

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I do use Brasso, but then wash it off completely with IPA or petrol (outside!) and then polish with chalk. Only bother with this with movements that were polished originally and not lacquered, such as French roulants.

As for movements that were lacquered originally, I'd go for what the folks above say.
 

Betzel

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Dec 1, 2010
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what would you recommend I use and should I coat the brightened brass when finished?
A variety of choices, eh? Since this was posted in a "restoration" category, and the clock is pretty old, restoration would maintain the original look, including the normal effects of time passing. I don't think much was lacquered in 1890, so it would have tarnished and dulled naturally over the last 130 or so years. What condition is it in now? If the pendulum bob has an even-looking patina, I would suggest leaving it alone. Hard to do though.

If it's super dark and gritty from isolation and exposure, you could use some wax as discussed. If you don't rub too much of the patina off when putting on the wax, or "make it even" by hitting only the darker spots a bit more with your thumb, that may help a little and it may not get much darker over time. This can also protect it against future fingerprints from normal oil on hands, etc. when you play with it, so it's something to consider. Same thing generally goes with the movement: just clean is the goal, no more than that; only polish the pivots. Also hard to do.

If it's partially lacquered, meaning it was polished by someone then sealed a few decades ago, but some of that has since flaked off, and some not, then it will have "black streaks" against polished brass. To me, this qualifies as a previous "repair" gone astray. I would strip, even it out, darken if needed and then let it tarnish naturally. Same thing if it took a hit, etc. If you later decide you went too far brightening, you can put back maybe 10-15 years or so, but once polished smooth it will take another 130 years to return to where it was. So, if you want it to pop, how far to go is up to you, but less is probably better? ;-)

There are fancy chemicals that will re-darken brass, and home-brew solutions with heat, salt and vinegar, but it never goes all the way back. This is why the PBS/A-R folks say that, and why coin collectors won't pay much for coins that have been cleaned or polished?
 

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