posted 09-05-2003 01:06 PM            

If the blemish is in fact corrosion and the metal has been corroded by a chemical force I may abbrade it to even out the metal or I might be able to planish out the irregularity with a fine polished hammer.

The black spots are often removed with a slightly more abrasive compound such as tripoly or FFFF grade pumice and sometimes Semichrome Polish. I then finish off with a regular silver polish.

There is always the chance that the use of aggresive compounds will reveal FireScale on the article being restored.

I recommend only using hand buffing and polishing.

posted 09-05-2003 07:23 PM            

First of all, ammonia added to your silver polish will remove some of the spotting far better than just using silver polish. I found this tip in a book of old formulas and it does work! One of these days, I'm going to try just sitting a dish of ammonia in a closed container with a piece of silver in it and see if that will loosen the spots any! When I get around to it (and don't hold your breath), I'll let you know what the results are.

Corrosion can also mean that the piece you are having problems with is silverplate. I assume vathek knows silver when he handles it, but just in case he missed on ths one...

posted 09-06-2003 03:51 PM            

I had thought to try just enclosing them in a case (old aquarium was what I was planning on using) and see if when shut up with them if the fumes from the ammonia would loosen the bad spots.

I will try the soaking on some old plate pieces I have. I often add a lot of ammonia to my polishes on the Victorian silverplated pieces, which turn quite black with age. If the soaking will do it, there are a few I intend to keep because I love them but just won't use them as dark as they are! I'd rather sell them, properly explained to the buyer, than to put more time in cleaning them. Some people actually prefer them black!

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Anuh

posted 09-07-2003 02:15 PM            

quote:

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I had thought to try just enclosing them in a case (old aquarium was what I was planning on using) and see if when shut up with them if the fumes from the ammonia would loosen the bad spots.

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I think you will be disappointed if you try this. I have used commercial ultrasonic cleaning solutions (which contain ammonia), both with and without the ultrasonic cleaner, to clean brass, and the immersed parts clean nicely, but anything left sticking out and exposed to the fumes alone turned black. I have tried household ammonia diluted in water with the same results.

I suspect that the black spots on silver are indicative of pitting, or will become pits if left untreated, so chemical cleaning seems necessary to penetrate deeply enough to remove all the oxidation, but complete immersion is necessary.

I have had occasion to (and will not again) use a commercial urea based silver cleaning solution. It turned the black oxidation into a white material that washed off easily. It worked, but it smelled very bad, and may be too harsh to use routinely.

posted 09-07-2003 07:13 PM            

Another thing that DOES work (and was used by Stieff Silver Co. when I worked for them in those same long ago years) was to put all the silver into a solution of STP in hot water in an aluminum pail. It chemically changes the tarnish.

This works fine with lightly tarnished pieces, and when you remove them, you rinse them off in clean water and buff them bright. However, it doesn't seem to work well on the Victorian silver, where mixing ammonia in with the polish DOES work far better than the polish alone.

That, too, may remove some of the oxidant in the crevices. You need to be clear on which is worse to you.

I generally polish with Simichrome and even batches I've done wth the STP treatment, if badly tarnished to start with will require that to brighten them back up. It has something to do, I believe, with the chemical change from tarnish back to a silver deposit. It's like removing rust. It never truly becomes part of the iron object again - the most you can expect is to have it benignly and gently removed!

posted 09-09-2003 03:43 PM            

I do not think I would want to use this method. Perhaps the chemists in the group could shed some light on this method.

posted 09-10-2003 07:06 PM            

quote:

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Originally posted by FredZ:
I think it might be TSP TriSodium Phosphate.. I would be curious to see if this works.

Fred

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You are right, Fred. I suffer from a bad case of Flabby Brain Syndrome some days, aka FBS. You may find yourself having to read around my mistakes when I really get started typing. Yes, TSP is what I meant. It's the main ingredient in Spic 'n Span, but the pure thing works better.

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Anuh

posted 09-10-2003 07:09 PM            

Just don't leave it in place too long!