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Old 5th Jan 2014, 9:42 pm   #1
robin coleman
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Default What is the best way to clean brass

I have a brass bulb holder, a dolly switch and a mechanism to clean. Has anybody got any suggestions for cleaning them? I have thought about cleaning them by electrolysis using stainless steel as an electrode and citric acid as a solution. Would this work? If so what voltage would I need? Are there any other ways?

Regards, Robin.
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Old 5th Jan 2014, 10:24 pm   #2
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Default Re: What is the best way to clean brass

If the whole thing will not be harmed by immersion, I'd chuck 'em in bowlful of Coke for 24hrs. That's the drinkable Coke, by the way!

Barry
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Old 6th Jan 2014, 12:45 am   #3
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Default Re: What is the best way to clean brass

I've never restored any brass, but the thing to remember is that it is an alloy and you might get preferential attack on different phases by reactive chemicals. De-zincification is a terms that lurks at the back of my mind.
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Old 6th Jan 2014, 9:23 am   #4
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Default Re: What is the best way to clean brass

If you go too mad with the strength of acid used when cleaning brass, you will end up with a coppery pink surface.
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Old 6th Jan 2014, 9:41 am   #5
robin coleman
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Default Re: What is the best way to clean brass

I may try the Coke method, as in a previous job I made plastic barrels for a company that produced the concentrate. Plastic had to be used as the concentrate dissolved a one penny coin.

Regards, Robin.
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Old 6th Jan 2014, 9:43 am   #6
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Default Re: What is the best way to clean brass

used to use Tabasco when cleaning up corroded Brass fittings on my yacht, a short immersion or a soaked cloth brings them up like new

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Old 6th Jan 2014, 9:56 am   #7
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Default Re: What is the best way to clean brass

Ammonia in hot water will clean and brighten brass in a few hours.

I think this has been discussed on here many times before but clock cleaning solutions such as Horolene contain ammonia, detergent and oleic acid. They will clean brass very quickly.
Can you "borrow" some from a local clock repairer?

To give a matt finish that lasts for years, such as those on 13 amp plug pins, nitric acid followed by chromic acid is used commercially, but these substances are quite dangerous and difficult to obtain, so that's just for information.
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Old 6th Jan 2014, 6:18 pm   #8
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Default Re: What is the best way to clean brass

I have cleaned up badly oxidised pins of old mains plugs using the wire brush that is fitted to my bench grinder. It can produce a highly polished finish in a short time. I have cleaned up relatively inacessible contacts in things such as old-style Ever Ready cycle lamps using a 12v minidrill (Dremel type) fitted with a wire cup brush. My drill body is about the same diameter as a U2 battery so aligns itself nicely with the battery contact when inserted into the battery compartment. The wire brush method is only of use if you want to end up with a highly polished surface.

HP sauce and malt vinegar are other things that can rapidly remove the tarnish from bronze coins, but I haven't tried them on brass.

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Old 6th Jan 2014, 7:56 pm   #9
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Default Re: What is the best way to clean brass

Using any kind of electrolytic process for cleaning things that have complicatedly-profiled surfaces is tricky - the current-flow into the more-occluded parts of the surface will be lower than the freely-ecposed parts.

Brass being an alloy you need to be aware that it may not electrolyse uniformly [the different metals in the alloy will be eroded in proportion to their position in the Electrochemical Series]. Even ordinary vinegar selectively goes for the Zinc in brass, leaving a coppery-coloured surface.

The best way I've found to clean up brass is to use one of the little fibreglass-bristle 'soldering brushes' that look like a propelling pencil. You can work the bristles into nooks and crannies to work out the years of accumulated muck, and the bristles give a non-surface-damaging burnishing effect.
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Old 6th Jan 2014, 9:10 pm   #10
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Default Re: What is the best way to clean brass

The acidic domestic cleaner, Viakal, cleans severely corroded brass very quickly then give it a rinse in a strong washing up liquid solution to neutralise the acid. Some light polishing may be required to remove any red tarnishing (copper oxide from the corrosion not the Viakal).
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Old 6th Jan 2014, 9:42 pm   #11
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Default Re: What is the best way to clean brass

Now I am spoilt for ideas. I will try a few out with some old pieces of brass which I have dug up from my allotment.
I don't know what they were doing on it but I have found loads of plug pins and old battery cells.

Regards
Robin

Last edited by Mike Phelan; 7th Jan 2014 at 9:56 am.
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Old 6th Jan 2014, 10:03 pm   #12
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Default Re: What is the best way to clean brass

You don't say how heavily corroded the brass is.
If it is just dull or dirty then a metal polish on a rag will bring back the shine.

I used some grade 0000 wire wool wetted with vegetable oil to remove varnish, paint and tarnish. It was relatively slow but it did polish the brass to a shine with hardly any visible 'brush' marks.

More aggressive abrasives will remove corrosion but will leave visible scratch marks.
Acids may leave pitting.

Verdigris, the green corrosion of copper and brass severely irritates my nose and lungs and I will always use liquids with the abrasives so as to avoid dust.

A brush with brass bristles would remove some dirt without scratching the surface.
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Old 6th Jan 2014, 10:54 pm   #13
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Default Re: What is the best way to clean brass

Any mildly acidic solution will remove tarnish - Coke and vinegar have already been mentioned. Any cleaner which claims to remove limescale (e.g. Cillit Bang) is likely to be acidic so will also work.

I mostly just use metal polish or T-Cut though.
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Old 7th Jan 2014, 11:51 am   #14
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Default Re: What is the best way to clean brass

Coarse car cutting compound is good where the item is really tarnished and you're not looking for a perfect, mirror finish. I've used it on our 1950s window stays etc. which were very crudely finished, and it manages to make them look nice enough.
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Old 7th Jan 2014, 1:51 pm   #15
robin coleman
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Default Re: What is the best way to clean brass

It is verdigris that I am trying to remove not tarnish I think it must have been in a damp place
Regards
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Old 3rd Jun 2014, 5:29 pm   #16
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Default Re: What is the best way to clean brass

Amway have a product called metal cleaner and is composed of Citric acid I believe but it has been awhile but it cleaned up copper and brass well. I would try a toothbrush and cut a lemon or an orange in half and use the juice. As with any chemical you would want to flush it well after cleaning. Hope this info is helpful.
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Old 4th Jun 2014, 1:04 pm   #17
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Default Re: What is the best way to clean brass

Quote:
Originally Posted by Mike Phelan View Post
I think this has been discussed on here many times before but clock cleaning solutions such as Horolene contain ammonia, detergent and oleic acid.
Interesting - but won't the ammonia and the oleic acid neutralise each other? Or is the resulting salt ionised, so that the ions are still free to do their job on the brass?
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Old 5th Jun 2014, 9:17 am   #18
Mike Phelan
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Default Re: What is the best way to clean brass

Don't know but with ammonia being alkaline you would think so.
I know that I have used Horolene that might be a year old and it still works as well.

For Robin's problem it's really going to need some sort of abrasive, though.
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Old 5th Jun 2014, 11:49 am   #19
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Default Re: What is the best way to clean brass

Don't you guys have Brasso?
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Old 5th Jun 2014, 12:19 pm   #20
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Default Re: What is the best way to clean brass

With the disappearance of traditional hardware shops from the UK, it's difficult to buy Brasso except in silly little 175ml overpriced containers.

Having been cleaned, brass always tarnishes again, so unless it's being used as an electrical conductor, it may pay to lacquer it.

I must admit to dunking my front door letter box in sulphuric acid and then washing off the copper deposit.
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