Cleaning Brass?

[Anonymous]

Asking the horologists amongst us.

[Andy CarlsonParticipant @andycarlson18141]

I haven't seen that specific episode but from what I recall he uses a chemical (ammonia based I think) bath with a sort of chip pan basket for the parts. Not sure if it is hot or cold.

I've a book that recommends ammonia for cleaning brass clock parts too.

I've also read articles online by museum conservators advising against using ammonia because it leeches zinc from the brass, leaving it looking very pink after repeated use. I read that and went for citric acid dissolved in warm water to clean some already pink looking brass (lathe) parts.

So there seem to be two schools of thought on this, sorry!

[Old SchoolParticipant @oldschool]

You can buy a solution for cleaning clock plates and wheels we just called it “pickle” by the smell ammonia based. The brass would come out clean it could then be polished on a polishing wheel or if a less shiny finish was reguired a fine wire brush wheel.

[Michael GilliganParticipant @michaelgilligan61133]

If you are right, Andy … which I would think you are … The commercial product is [was?] Horolene

Rather out-of-favour because of the de-zincification that you describe … The extent of which varies greatly according to the microscopic structure of the brass.

The old cast brasses in antique clocks being the most vulnerable !!

… use with extreme caution.

MichaelG.

[Adrian DownesParticipant @adriandownes83818]

Traditionally –

4 pints of water,

2 table spoons soft soap – dissolved by boiling

Then

2 table spoons full strength ammonia.

Soak & scrub with a suitable brush untill clean.

Rinse twice in hot water

Dry thoroughly in boxwood dust

Brush up with a soft brush liaded with French chalk

Peg out pivot holes

& the job is done!

[Bob StevensonParticipant @bobstevenson13909]

Actually, cleaning a dis assembled clock is a collection of separate tasks, and thus, a collection of methods being both 'wet', 'dry' & mechnical in character………If you have no 'previous' in this may I suggest the following?…….

Buy some Horogrene in a sample pack from one of the online clock/watch supply houses such as Cousins…….Horogrene is the modern friendly equivalent of the older ammonia based fluids and works just as well if not quite as quickly. The sample pack contains three botttles for removing old laqueur, deep dirt and old lubricants etc. Once you have cleaned the bits to your satisfaction move on to…….

Buy some FINE wire wool…the best is that made by Liberon as '0000'….it is 'spun' in one direction, needs to be kept very clean in it's back and only carefully removed to cut of a piece with scissors. This stuff is brilliant and will quickly put a lovely finish on the bits but be sure to keep the main stock CLEAN and constantly renew the piece being used as ANY foreign bodies will instantly spoil the finish.

Finally, use a small polising mop on your Dremel type tool to clean any small details…you can usefully use T-Cut car body compound with this to enhance the details etc

…..Now you have to re-lubricate and reassenble the clock which is another set of challenges best left for another post!….Hope this helps!

http://www.horogrene.com/

Steel Wool Grade 0000 (Ultrafine)

[Bob StevensonParticipant @bobstevenson13909]

Ian,….Be aware that even the 'safe' citric acid will make brass pink quite quickly and for that reason I now rarely use it….pinkness is caused by the acid removing the top microns of zinc unevenly and thus making the copper visible.

[TomfileryParticipant @tomfilery]

Re Bob S and Ian B's comments re citric acid.

Freshly mixed citric acid will not make your brass go pink – I use it regularly for cleaning small rivets before soft soldering. However, once you have put copper in it, any brass then dipped will turn pink. So if you've pickled some copper then don't use the pickle to clean brass!

I don't make, or restore, clocks and it may be that certain grades of brass react differently.

Just my experience from observation.

Tom

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Tomfilery on 08/01/2021 10:28:23:

[…]

… it may be that certain grades of brass react differently.

 

.

They certainly do, Tom

… as mentioned above:

The extent of which varies greatly according to the microscopic structure of the brass.

The old cast brasses in antique clocks being the most vulnerable !!

MichaelG.

.

Ref. __ https://www.copper.org/resources/properties/microstructure/brasses.html

Edited By Michael Gilligan on 08/01/2021 14:42:56

[Roger HartParticipant @rogerhart88496]

I too worry about the intrinsic quality. Is this one of those 'Napoleon's Hat' clocks? If it is the wheels and plates were never polished, they were as stamped out and never meant to be looked at.

Nearly 60 years ago I had a Saturday job in a clock shop and got the mucky jobs – cleaning clocks. For a Napoleon's Hat it was strip down, mark the going, striking and chiming wheels for identification and relative position. Then clean in 'benzine', dry off and brush with french chalk on a clock brush then peg out the holes. Rebush or hammer the holes as required. Clean out the spokes with a 3 corner graver, brush the wheels and reassemble.

For a nice Grandfather or carriage clock it was strip down, mark the going etc then polish all the bits with Brasso with a selection of really mucky crusty clock brushes and an electric polisher with a bristle wheel. Used to get covered in Brasso and black fingers. A cloth wheel and rouge for the plates and barrels except the front plate. Once all polished it was wash in benzine, re-do the grimy bits and rewash then dry off, french chalk etc.

Springs were anchored on a nail and cleaned with brasso while stretched out then benzined etc.

I was allowed to reassemble grandfather clocks but carriage clock bits were made perfect then put in tissue in a box and handed to No 2 Clockmaker who would moan like hell if any muck was found. All this for 10 bob and I hate the smell of Brasso to this day.

I have used the ammonia stuff and it is OK but does not seem to make the bits as bright. I hear some professionals make noises about 'preservation' as a cover for not doing too much. As it is quite easy to break a pivot etc I can understand. Also apprentices cost a bit more than 10 bob these days.

So have a good look, was it ever properly polished. That makes a big difference. BTW the 'benzine' was probably not really benzine but common or garden petrol, loads of it under the bench. Elf n Safety was not a big thing back then. TBH I think Fairy liquid and hot water would be OK and SWMBO's toothbrush.

One of those grandfathers was a big heavy job with latches holding the plates together. No 1 Clockmaker said – this was made by Tompion lad, be careful.

[Mark RandParticipant @markrand96270]

Benzine was/is light petroleum spirits. benzene is the nasty stuff.

As a youf I ended up mending my mate's dads "Tickoprint"* Quartz crystal oscillator based watch setting machine.

He used Benzene! Died later from cancer…

*Quartz crystal oscillator with dividers down to a multiple of a watch escapement's ticking speed, driving a rotor with a helical ridge on it like a mower reel. The watch's ticking was picket up by a microphone and amplified to drive a hammer bar towards the rotating cylinder. When the watch was accurate it produced a straight line of dots on a till roll. too fast, the line slopes one way, too slow it slopes the other. The watch/microphone was in a jig that could be rotated to test the watch in different orientations, to mimic wearing. Fault was an OC81 transistor that had died.

[BazyleParticipant @bazyle]

I believe ammonia causes stress corrocison cracking. It infiltrates sown the brass grain boundaries and causes cracks to appear infive to ten years which is why so many people think it is ok. The next repairer will see the damage.

Edited By Bazyle on 08/01/2021 19:29:18

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Ian B. on 09/01/2021 10:50:07:

[…]

As regards the movement, the plates are smooth for the front plate, the rear looks to laquered badly and there is a pattern of what looks like tiny centre pop marks.

[…]

.

I can’t recall the fancy name for that, Ian … but it’s a flattening & stress-relieving process

Everything you describe is indicative of [very appropriate] Production Engineering of a mass-market clock.

Tinker with it, and learn from it … but don’t try to make the proverbial Silk Purse out of it.

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Michael Gilligan on 09/01/2021 11:13:59:

Posted by Ian B. on 09/01/2021 10:50:07:

[…]

.

I can’t recall the fancy name for that, Ian … but it’s a flattening & stress-relieving process

.

Got it

… See post #4 here: **LINK**

https://mb.nawcc.org/threads/clock-movement-plate-finish-appearance.103944/

MichhaelG.

[Author]

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