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Polishing Brass

2K views 20 replies 12 participants last post by  lifestooshort81 
#1 ·
Hi folks,
I'm attempting to polish up a 100 year old brass light fixture. It's solid brass. I've tried all the "over the counter" methods like brasso, etc...

I've even tried a chemical bath (muriatic acid) and then buffing it on my buffer. I used brown tripoli to start. It's working amazingly where the brass is good however there are "Pitts" I just can't get out. I use the term Pitt loosely. It's not actual cavities in the metal but more so little red oxidation spots. I just can't seem to get rid of them thru polishing.

Does anyone have any suggestions on how to get rid of these? My next thought was to try a very high grit wet sandpaper and sand it out then re polish on the buffer. I'm reluctant to do this though as I don't want to scratch the metal.

Any input is mucho appreciated!!!!
Thanks,
Al C
 
#2 ·
Doubt that it is solid brass. Most likely plated brass. If Brasso, Baking soda paste is not working, then it is not brass. Post some pictures of the fixture. If it was solid brass, it would be really heavy, and would have a bolt at the top, that is used to secure it to a support beam above the ceiling, when put in place.
 
#3 ·
...however there are "Pitts" I just can't get out.
I use the term Pitt loosely. It's not actual cavities in the metal but more so little red oxidation spots. I just can't seem to get rid of them thru polishing.
A picture would help.

I've never needed anything stronger than the automotive type of
white polishing compound for the brass items I've had (beds, lamps, etc).
 
#4 ·
It's definitely solid brass. Light fixtures from this vintage did not plate. It's also soft and I deformed a small corner in polishing.

The picture doesn't do justice but see attached. I forgot its really easy to attach pics here. The truck forum I'm on doesn't make picture posting an easy task!

The spots you see are what im talking about pre-polish. Once polished they come out with a hint of red to them. it's not clear coated or anything (as one might assume its oxidation under the clear coat) it's part of the metal itself. Maybe I just need to polish more and more or use a heavier grit polish?

Thanks again.

Yellow Brass Metal
 
#8 ·
It's definitely solid brass. Light fixtures from this vintage did not plate. It's also soft and I deformed a small corner in polishing.

The picture doesn't do justice but see attached. I forgot its really easy to attach pics here. The truck forum I'm on doesn't make picture posting an easy task!

The spots you see are what im talking about pre-polish. Once polished they come out with a hint of red to them. it's not clear coated or anything (as one might assume its oxidation under the clear coat) it's part of the metal itself. Maybe I just need to polish more and more or use a heavier grit polish?

Thanks again.

View attachment 72180
Have you tried Noxon? it's my favorite polish.

apply and use a very soft toothbrush to polish it,
rubbing gently; then rinse thoroughly.

Except for silver ( not recommended for silver) it works
great on copper, stainless steel, brass,
aluminum, chrome, pewter, bronze and copper...

I polish my stainless steel sink with Noxon about once a month
and it comes brand new.

good luck, hope it works, keep us posted.
 
#6 ·
Brass is not going to be so soft, that it will warp or bend while polishing. Plating they did a hundred years ago. Again, if it is solid brass, it will be very heavy. Electroplating has been around as long as there has been the ability to create electricity. Electrochemistry which was used in the late 18th century.

Modern electrochemistry was invented by Italian chemist Luigi V. Brugnatelli in 1805. Brugnatelli used his colleague Alessandro Volta's invention of five years earlier, the voltaic pile, to facilitate the first electrodeposition. Brugnatelli's inventions were suppressed by the French Academy of Sciences and did not become used in general industry for the following thirty years.
 
#7 ·
What you have is plated Brass coating on tin. If it was real brass, there would not be any chips in the coating like that. Also placing in Muratic acid is bad for any metal, because if you do it wrong, it will eat and damage the metal worse than just leaving it as is.
 
#10 ·
So does Salsa, kool-aid, citric acid, cocktail sauce, vinegar. Anything with a acid base in it, will work. Toothpaste like Tom's of Maine will also work. We used it to clean up some old swords that my wife's grandmother had, that were her deceased spouse, that was a Captain in the Darby's Rangers, during WWII.
 
#12 ·
Amazing what Arsenic & starch does for Silver, isn't it. Of course, hope that you are not going to be using that by product for another dish.

There is a lot of old ways of doing stuff, that people forget about, that our grand & great/great-great grandparents used.
 
#14 ·
I was admiring a well polished old kerosene automobile lamp in an antique shop. I asked how he polished all the tight joints so well--

His 'secret?'--replating---he sent the thing to a brass plater ---looked good.
 
#15 ·
When I was a kid I had a chemistry set and one of the chemicals was copper sulfate. This was used as the medium for copper plating with a 6V battery. Wonder what chemical would be needed to do brass plating.
 
#18 ·
on second thought i suppose its brass plated tin however I have been buffing/polishing this for some time and have yet to buff down to the tin. There isn't anything "solid" on the fixture it's all light gauge metal. I just assumed it was brass because I didn't think they bothered plating it.

Doing a little more research the spotting i'm describing is what is apparently called red rot? Does this sound correct? I would say the quality of the chandelier is equivalent to that of a brass musical instrument (i.e. trumpet). There is tubing and then the canopys as seen in the picture I took.

I don't need this to be perfect as it's just a small project for myself but I would like to get it as clean as possible!

I've tried all the simple cleaning solutions (ketchup, never dull, noxon, brasso, etc...) which is why i'm actually buffing it with compound and a buffer wheel.

Thanks all for the input. I may just have to have the pieces re-plated if I can't get rid of the red spotting.
 
#19 ·
If I'm not mistaken, the "red rot" you refer to is the iron oxide in the base metal of the lamp contaminating the brass layer. If you are going to send it out for re-plating anyway, you could try like 600 grit wet/dry and see if you can get it off before you hit the tin. Then just work up grits until 2000 and buff back out. But I'm sure you'd be into the base metal by then.
 
#20 ·
Before you attack it with sandpaper, try some very fine steel wool or a very fine scotchbright pad. If it doesn't buff out with either of these, then it is probably some contamination from the base metal that has leached through the brass plating. Even a small defect in the base metal can hold a tiny amount of the suspension solution used during the plating process. Eventually the trapped solution will discolor the plating. Sandpaper will surely grind through the plating.
 
#21 ·
I've actually tried the 600 sandpaper trick already. I wasn't too brash with it but I did enough where as I thought I'd be at the base metal and wasn't. When I buffed it the "scratches" went away.

I did a little more research and the red rot is actually the copper in the base metal. The base isn't tin, it's actually stamped/extruded brass. As one alloy wears away from oxidation it leaves the copper to shine thru in a faint red spotting. This is apparently common in trumpets or other brass musical instruments. So that being said I found a brass electroplating kit for $50. It's actually what they call brush plating but electroplating none the less. For $50 I may give it a shot. This is just a little side project for me so I don't necessarily have a budget. It's zero LOL

Ill keep y'all posted if I go through with it!
 
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