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Silver Stripping from brass musical instruments

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Q. I've an old silver plated brass saxophone which the plating is very bad on. It has a "bead-blasted" type finish under the plating over most of the instrument. If I buff off the plating and polish and lacquer or buff of plating and re-plate I'd remove some metal and surface "blast" finish. There must be a way to chemically strip off silver while leaving brass underneath level or even un-etched so that instrument can be replated while maintaining thickness and weight of instrument. Anyone do this?

Jon Van Buren
piano service - Holland, Michigan, USA


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Q. I recently silver plated some brass stampings using an immersion method with Jax Silver Plating Solutionamazoninfo with less than desirable results. The pieces were clean and bright and were not lacquered and I coated them 3 times with the solution. Twice, I rinsed them in warm water after they turned silver color and when the brass color started to show through, I repeated the process and didn't rinse the parts. Still the same result.

My question now is, since this method is not working and I have to go to a professional silver plater who uses electroplating methods, how do I remove the existing silver plating. I could probably sandblast the pieces but am wondering if there is a solution that I can soak them in to avoid this.

Anybody have an answer to this problem? Any help would be appreciated.

Thanks,

Lance Fisher
- Fairlawn, New Jersey


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A. A 50 percent nitric acid and water solution heated to 120 degrees should remove the silver. CAUTION dip for 10 seconds rinse immediately with water repeat until the silver is removed will take brass if left on too long.

Thomas Crowley
- Fitchburg, Massachusetts



A. Thanks, Thomas. Note, though, that nitric acid is quite hazardous to use, so its use should probably be restricted to where the operator has had hazmat training, and usually industrial settings.

Lance, since you're planning to send it to a plating shop anyway, I'd suggest shipping it "as is", to them anyway; they'll have little difficulty dealing with it. They will probably just buff it off or chemically strip it in a flash. Good luck.

pic of Ted Mooney Teds signature
Ted Mooney, P.E. RET
finishing.com
Pine Beach, New Jersey

Nitric Acid



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Q. I'm wanting to strip silver plating off of a brass musical instrument. Are there any chemicals that will strip the silver plating off without damaging the brass? Thank You!

Richard Crocker
- Greenwood, South Carolina


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A. Yes, there is, Richard, as you can read above. But you might prefer to let a plating shop use them rather than trying to use them yourself. Not only may the stripper be dangerous, but what would you do with the now soluble silver that you've stripped off? It's a very powerful biocide that the sewer authority doesn't want you to flush into their system. Please entertain the possibility of having a plating shop do it for you. Good luck.

pic of Ted Mooney Teds signature
Ted Mooney, P.E. RET
finishing.com
Pine Beach, New Jersey


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Q. I am inquiring about a chemical that can be used to remove silver finish from brass instruments. I need it to take the silver plating off of the outside, but to not interfere too much with the brass underneath. I understand most chemicals of this nature will eventually eat the brass as well. I am looking for something that will eat the silver away before it attacks the Brass.

Thank you,

Michael Del Quadro
a musical instrument distributor - Las Vegas, Nevada, USA


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A. The Metal Finishing Guidebook offers a good silver strip. I hope James or Ted will jump in here to recall the formula as I do not have a Guidebook here. I think it is 960/40 That is 960 ml/l of nitric acid and 40 ml/l of sulfuric acid.

Use semiconductor grade nitric acid (available in bottles).

Wash you parts first, making sure they are VERY clean. Best is hot water and clean air to dry them. Do not touch with fingers and make sure they are DRY before stripping. Watch parts for removal of silver. Most is thin and comes off in minutes. Keep the tank covered and sealed when not in use! This will limit the water pick up from the air. VENTILATION REQUIRED! This is strong and bad stuff. Buy baking sodaamazoninfo in the big box. gogglesamazoninfo, protective glovesamazoninfo, apronamazoninfo, water flush, all the safety stuff.

When solution no longer works, oh boy you have a hazardous waste. In the end plan to pay bucks and time to have it tested and picked up. (Charge a lot for stripping and put the money away). You can get most the silver out with table salt sprinkled on the top and absorbed with T.P. This works if you have a furnace to smelt silver. It has been a long time but I think you'll need some Boraxamazoninfo for flux. (TREVOR, KEN I have a hunch you know this -- can you help?)

Jon Quirt
- Minneapolis, Minnesota


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A. It is 950 ml/l sulfuric acid and 50 ml/l nitric acid. Use this at 180 °F. Enter the bath dry.

totter James Totter, CEF
- Tallahassee, Florida



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thumbsup2James, Thanks for bailing me out.

Jon Quirt
- Minneapolis, Minnesota


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"It is 950 ml/l sulfuric acid and 50 ml/l nitric acid."

Q. What exactly does this mean? is ml/l a ratio ? What percentage of purity or concentrations of these acids should be used?

I'm also stripping silver plate from brass music instruments. I need to make a solution 10 to 15 gallons in size.

Thanks

Stuart Adams
MUSIC INSTRUMENTS - Atlanta, Georgia

Sulfuric Acid


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A. ml/l means milliliters/liter. You put x milliliters of the acid into 1 liter of pure water (faucet water won't really work as it usually has trace amounts of chlorine and larger amounts of things like fluoride). You multiply the ratio by the amount that you need.

Bart Humphries
- Redlands, California



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Q. My hobby is collecting car mascots (usually plated brass/bronze). Many of these have seen substantial wear to the plating (chrome or silver). I would like information on removing these platings myself, so that I can have the mascots replated, or left as brass or bronze to patinate naturally.

Ronald Rose
hobbyist - Co. Durham, United Kingdom

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