Metal finishing Q&As since 1989
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Can't remove tarnish from old brass lamp in this lifetime
Q. I have just bought an old Dutch tiered brass lamp. I have been rubbing it with Brasso [on eBay or Amazon] but it is too much work. I have also tried using fine 00 steel wool [on eBay or Amazon]. Too much hard work also ...it would take the rest of my life. Is there any acid bath that this lamp, if dimantled, could be dipped in? Thank you.
Margaret altinkhobbyist - France, Besneville, Manche
August 10, 2008
A. Hi, Margaret. The first issue is removing the tarnish.
Brasso
[on
eBay or
Amazon] is great but terribly slow. Other polishes like
Barkeeper's Friend liquid soft cleanser
[on
eBay or
Amazon]
contain acids and are much faster. The fastest of all is vinegar
[in bulk on
eBay or
Amazon] plus salt, but this leaves brass very orange, so you'd need to go back to something like Brasso for a while to restore the warm glow.
The second issue is that you may be expecting shine and the brass may never have been buffed to a shine. The only things that shine are smooth things. If these items were rough cast brass they can only be shined by buffing (a power wheel and compound), they can't be shined with chemicals. Good luck.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
August 12, 2008
A. Try 5% ammonium citrate(50 gm citric acid/1 Lit water+some ammonia, pH must be 9!).Hope it helps and good luck!
Goran Budija- Cerovski vrh Croatia
August 13, 2008
Q. We live in an old house in Scotland that has a front door with an inordinate amount of door furniture, some of which is bronze, some brass and some "copper" brass. The pink seems to be the result of some sort of chemical treatment - there are splotches and obvious patches of brass showing through on the back. I would like to turn the remaining brass this colour - it goes quite nicely with the bronze. Does anyone know what I should use?
Sarah Woodburyhobbyist - Ormiston, East Lothian, UK
August 28, 2008
A. Hi, Sarah. It's obviously hard to discuss metal colors with text rather than pictures, so if you can send a photo, that would help. But vinegar plus salt will tend to dissolve some of the zinc out of the brass, or "dezincify" it -- which leaves it a raw color that some would describe as orange or salmon rather than warm and golden. It might be a stretch to call it copper colored.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
August 28, 2008
Q. I have just purchased a beautiful brass wall hanging (bijan).
It was painted I used hot vinegar to get the paint off.
Now it has a copper hue to it -- what can I do?
- girard ohio usa
October 4, 2012
A. Hi Sandi. We appended your inquiry to a thread where the topic was already being discussed. Patient application of Brasso will bring it back to brass color. Good luck.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
October 4, 2012
How to de-zincify brass to make it red
Q. I need to dezincify brass wire 85/15 Zn to obtain a redder finish.
What's the process, and what chemicals would I use?
- Chelmsford, Essex, United Kingdom
January 22, 2014
A. Hi Bernie. Zinc is a much more active metal than copper, and either acid or alkaline can dissolve some of the zinc, leaving the brass redder. Simply cleaning brass with vinegar and salt will give it a raw, reddish cast. Immersing it in salt water for extended periods will turn it reddish too. The thing is, this discoloration probably doesn't extend very deep and therefore probably isn't very permanent.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
January 2014
Achieving a Rose Gold Finish on Brass 85/15 zn
Q. Dear sir.
We are looking to achieve a Rose gold finish with brass wire 85/15 zn. Then passivate and lacquer, which should seal the surface (retaining the redness).
Any thoughts please?
Best regards,
- Chelmsford, Essex, United Kingdom
January 23, 2014
Bernie,
There is a very simple patina process that works nicely for creating a red gold on most copper alloys, it's called rokusho.
There are several jewelry suppliers who will sell you a pre-mixed rokusho, or you can locate a fairly simple and easy recipe on the internet.
Failing that, an mild acid wash will probably give you a similar (or better) coloration.
Blacksmith - Lenoir, North Carolina USA
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