Cleaning old brass

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This might do the job...

Bill

I'm sure one can buy brass polish where you live. Here in NZ we have "Brasso", a mildly abrasive polish intended specifically for brass. The same firm makes a silver polish named ... (wait for it) "Silvo" which is apparently the same formulation but with considerably finer abrasive particles.

I would use a brass or silver polish along with a felt head polishing bit in a Dremel tool set at a slow running speed. You might need to use a soft bristle brush fitting in the Dremel for cleaning detail parts.

Brass tarnishes quite quickly, so it needs a coating (oil, varnish, paint) almost immediately to stop further tarnishing.

Greg.P.

"tex shalter" wrote

Only way I've ever found to get all the nooks and crannies perfectly clean again is to use a low-pressure air gun and fine grit aluminum oxide particles to clean off all of the old clear lacquer coat and tarnish. The trick is to go slowly and use just enough air pressure, lest you sandblast some of the fine details right off the surface!

As Greg stated, you then need to spray the nekked brass with another coat or two of clear finish to protect it from tarnishing again, and it will do so in just a few days if given a chance.

Hint: don't use gloss lacquer for this, as a gloss finish makes your brass locos look really dumb! Nearly all brass originally came from the factory with either a flat or a satin finish.

Pete

Years ago, mid-70s, I had great success using a brand name called Casebrite. It was available in gun shops and used by folks who reloaded their own ammo and had to clean up the re-useable brass casings. My brass painting days are over and have no idea if it's still available...EPA may have pulled it off the market. I believe it was a form of chromic acid.

Nevertheless, I found modest tarnish, as long as it was clean, provided an excellent surface for paints to adhere to what was shiny brass. I have some brass that was tarnished before painting and it still looks as good as the day it was painted. BTW, I painted with auto lacquers whenever possible.

Tomato sauce. I kid you not. Canned Hunt's tomato sauce.

Its slow, but safe.

On 1/17/2008 2:20 PM jJim McLaughlin spake thus:

I believe you, but what's doing the work is the acidity. I'd sooner use something less messy, like white vinegar. But heck, if all you've got is sauce, use it. (Actually, the sauce may be better for some places, as it'll stick and not slide off so easily.)

The trick, of course, is to cover the surface enough to cut the tarnish while avoiding getting the goop into places where you don't want it. Here, things like Q-tips, small brushes, etc., are your friends.

OK, Thanks everybody. soft acid from lemon /vinegar or tomato sounds easier to use than rubbing with metal polish. I paste it on with a brush and let the acid work until it starts to crust. It's the paste removal that becomes the trick.

I think there is already a lacquer finish though. I was tempted to dilute some muriatic acid (it's VERY strong) But wouldn't require much work to remove it and I know it can cut right thru the lacquer.

On 1/18/2008 7:30 AM tex shalter spake thus:

Use lacquer thinner (acetone or equivalent) to remove the lacquer. Much, much faster and less messy than using acids, etc., which can corrode your model.

Just follow the usual precautions: lots of ventilation, etc.