I just need some help about this topic on lead content in flutes of chinese origin.
I have been playing a pearl River chinese make for 7 months and the 'supposedly' silver/nickle plated lip plate now has small spots on it... doesn't go when I clean it and I just feared it may be some kind of corrosion.
Please let me know as soon as possible or I'll have to wait for a few months without playing before I can afford a new good one.
Some China manufacturers have, unfortunately, a bad reputation for their poor quality controls and the use of dangerous products that are banned in other countries. Recent scandals as the case of contaminated milk are an example.
But I do not see the relationship between the corrosion spots on the lip plate and "lead".
Unless you have some additional information concerning lead contamination (and it would interesting for us to know), your problem seems to be bad quality of the nickel silver nickel layer that covers the (probably) brass base material. Not serious, except for cosmetic issues. Beware if the nickel peels off, I would not swallow nickel at any price.
Brass is a combination of Copper and Zinc, so in principle there is no lead in it. But who knows in China?
It may be so, but my old flute is made of brass (no doubt) and I believe it is plated. Or so it behaves in respect to tarnishing. It is a Gemeinhardt M2 made in the 80's.
Now, if that base material is nickel silver and it has been plated, is it possible it shows those dark spots that cannot be cleaned?
I believe re-plating that lip plate would be easy and cheap, though maybe not long lasting. Also, there are products on the market that re-plate metals passively but lightly (without external electric currents involved).
I would be surprised if your Gemeinhardt is brass with silver plate. I can't say that it's impossible, but I've never seen one made from brass. There are many different alloys of brass and nickel silver. Nickel silver is more yellow than silver plate, but typically brass is much more yellow than nickel silver.
Yes, silver plate over nickel silver can definitely develop spots which cannot be cleaned. When there is any imperfection in the plating, the underlying base metal can corrode and appear as a dark spot. With brass, the spots tend to be a brownish-green color while on nickel silver, the spots will tend to be greyish in color.
While there are chemical-based plating compounds, the do not deposit anywhere near as much silver as electroplating and would not last very long. I would also be concerned about toxic chemical residue being left behind on any surface that comes into contact with your mouth. Most good repair shops can touch-up the plating or alternatively if you really want to do it yourself, check out Caswell Plug-n-Plate kits. Silver kits are about $40 USD, but a repair shop could probably do it for less than that.
The fire scale is a result of sulphur being absorbed from the atmosphere and into the surface while it is hot, reacting with the silver or the copper in the Sterling Silver, to make a black oxide.
Solid silver flutes are often silver plated to hide this. The more you try to polish such areas shiny, the bigger they get, because you wear away more plating.
this is incorect
firescale is caused when the copper in the sterling silver oxidises all metal alloys containing copper will oxidies when exposed to oxygen
this can be eliminated by using a flux and a deoxidiser commonly boric acid.
when heated it forms a layer of water soluble glass over the metal stoping oxygen coming in contact with the silver
this can allso be done by heating and soldering the item in a reducing atmosphear ie: oxygen free enviroment usualy created by surounding it in nitrogen.
firescale can be removed from sterling silver by doing whats called depletion the item is heated to a dull red and then placed in a pickle solution of 10% solfuric acid and 90% distilled water
this is repeted a number of times the aim is to deplete the outer layer of copper thus removeing the scale and forming a layer of fine silver usualy around 5 micron in thickness.
there is allso a number of sterling silver (925) alloys on the market now that contain a small amount of silicon and germanium that do not form scale under normal soldering and working conditions
Flutes typicaly will be plated after soldering and polishing to cover the scale as its not economical to spend the amount of time needed to remove it.
Most commonly plated in fine silver so it will not tarnish as non ferrous metals ie: gold, silver, platinum, palladium in there pure form 99.95% do not tarnish only metals alloyed with copper will tarnish under normal conditions
If my Gemeinhardt is not built out of brass, that's a good news for me. I was told the contrary some years ago, but looking carefully at the bare metal seen in the tenon, it seems a little whiter than what normal brass would be. Nickel silver, then?
I also played with mercury in my childhood. My father brought home a small bottle, we were astonished of the heavy metal inside and we performed all sort of tricks with it. There was mercury on the floor some times, though not in bed, as I can recall those times now. We collected the mercury by pushing with the fingers onto a piece of paper. It was also common that mercury thermometers broke while in use and in those cases the contents could spill on the bed and clothes.
Both my brother and me suffered a serious illness (a typhus type) when quite young; I was 8 and my brother 4 years old. We stayed in bed for almost three months, with incredibly high fevers. I still remember that my brother made the thermometers break (explode) because his fever was over 44 degr Celsius (about 111 deg Fahrenheit). So we had plenty of opportunities to get mercury spilt on us. We did not develop any visible consequence because of the fever or the mercury. But we escaped an almost sure death quite closely: a new antibiotic was put in the market just in time to save our lives. It was Squibb's Chloromicetin, or Cloranfenicol). It is still used these days to treat those fevers, many decades after that.
Sorry for the disgression, quite far from lead in chinese flutes
as to your last post borax is a flux used on the area being soldered to allow the solder to flow in to the join being soldered
boric acid is used to eliminate the risk of scale and it allso protects the polished finish the typical proceidure is as follows
the boric acide is mixed with methylated spirits to a consistancy not quite that of cream the item being soldered is diped in the solution and then shaken to get rid of any drips
with a lighter or match ignite the piece to burn of the metho
will only take a few seconds to burn off you will notice that there is then a thin white powdery filim completly covering the item flux the join and solder as normal allow to cool and place in warm water for 10 mins to remove the boric acid you will then notice that the only area that needs to be polished is a area of a couple centimeters sourounding the solder join as the original polished finish has been completly protected and unaltered this procedure is nearly allways used when resizing a finished finger ring so as not to alter its original polished finish ny using this method you could typicaly resize a ring up a number of sizes ie: soldering a piece of metal into the band then filing sanding and polishing the item within about 15 mins start to finish
without using this procedure it would take a bare minimum 1 hr.
i would use the same procedure to repair a silver service normaly haveing to resolder cup handles hinges on teapots as well as repairing antique jewellery in silver, gold
i fully recomend you try this method as you will never go back to useing anything elce it wiil easily halve the repair time on any finished product brought in for repair where soldering is needed and please let me know when you have if ya have any question's feel free to email me anytime allways happy to answer if i'm able to
and allso there is no reason to notify customers that a solid silver item has allso been silver plated. by law notification is only needed if the parent metal is diferent to the plateing being used ie gold onto silver, rodium onto white gold, base metal silver or gold plateing