Cleaning brass

[Capitol]

I'm doing a refurbishing job on an 80 year old steam pond yacht at the moment. I'm half way through the repaint job which is going well. This has lots of variously shaped brass fittings with all the black oxidation from 80 years of exposure. I've given the bits a soak in citric acid solution to get rid of the worst, but this has left me with very coppery looking brass. Before I settle down to the Brasso and a lot of fiddly hard work, is there an easier way?

[News]

In message , Capitol writes

Bowman? Lucky chap!

My inclination would be to throw the parts in a small tumbler with nothing more than hot water and some washing powder, which always works well with Hornby tinplate parts, Meccano, brassware etc. Failing that, very fine wire wool, but that is laborious, and would still benefit from Brasso afterwards.

[harry]

Buffing wheel for electric drill/bench grinder takes some of the work out of it,

[Andy Burns]

Does the acid dezincify the surface of the brass? We used to use lemons with salt as a mild abrasive on coal-scuttle, probably not left on long enough to have the same effect.

[Chris Bartram]

I've done small bits with a polishing wheel in a dremel with brasso. A bit messy, but fast and good results.

[Thomas Prufer]

"Vibratory tumbler" and "Rotary tumbler" are your friends.

Also "felt wheels" followed by something like a "spiral sewn buffing wheel" -- each will have an appropriate polishing compound bar, sold nearby.

Note that these are, in the best case, 12" diameter or more, and attached to a large three-phase stationary motor, not a little Dremel. However, the brass will gleam as it never has before in very little time.

(These tools will also break your arm if they catch and snatch, beware.)

Thomas Prufer

[Jonathan]

Coca Cola works for me

Jonathan

[Nightjar]

What has happened is that some of the metal has dissolved in the acid. The suspended copper redeposits, but the zinc does not. The resulting coating is thin, but polishing it off is probably the only practical way to remove it.

A polishing machine or a polishing mop adaptor kit for a bench grinder would reduce the amount of physical work. However, unless you have done machine polishing previously, it would be best to start off practising on some unimportant brass articles first.

[Peter Parry]

Only for about 2 nanoseconds as it does Mach1.4 past you left ear as it seeks out the far corner of the workshop never to be seen again.

[newshound]

That was my thought too, but polishing should help restore the colour.

[Jim Chisholm]

I've used:

to rejuvenate tarnished brass letterboxes and door knockers. It was recommended by someone responsible from such brasswork on a large Cambridge College. "contains Hydrogen Chloride apply with pad of woodworkers polishing cotton, allow to stand for 2 or 3 mins and agitate with No0000steel wool. Rinse and polish with metal cream "

[Bob Eager]

I used Rustins Brass Restorer (basically phosphoric acid). It worked very well.

[Brian Gaff]

Where is duraglit when you need it.. I used to find the big issue with brass was that it got pitted and looked awful. Brian

[F Murtz]

Rot, if it does so would lemonade or soda water. People used to tell me that but I put a penny and a sixpence in different fizzy drinks and they all did the same, I then tried to solder with coke and had no success.

[Capitol]

Earlier this week I was doing a recovery job on the nose pads of a pair of spectacles. These were retained by very miniature screws. Yes,in the course of 20 minutes, I managed with the aid of a magnetic screwdriver and a pair of tweezers to lose both screws somewhere on the desk. Fortunately I have a stock of clapped out reading glasses, so I was able to find replacements and finish the job but the ability of small things to vanish is a constant source of amazement!

[Andy Burns]

Rather than trying to catch them, or see where things go (not likely if I've taken my glasses off for close-up work) I find better results from listening to where they go ...

[Bob Minchin]

Yes the acid had pulled out the zinc locally just leaving copper, that has to be rubbed away but it is only atoms thick so brasso should do the job.

[Capitol]

I discovered that some of the discolouration was in fact varnish, which had been applied after the fittings were mounted. Fortunately it was shellac, so some meths removed most of it. The small fittings have now been refurbished using a combination of brass wheel in a Dremel type drill and a felt pad wheel coated with a liberal supply of Lidl sink cream cleaner as my Brasso supply appears to be exhausted. So it's onto some of the larger fittings tomorrow.

[Nightjar]

If it shoots past your left ear, you are running the mop in the wrong direction ;-)

[Capitol]

Or holding it in the wrong place.