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Lead contamination

I am desperately trying to find any articles on "removal of lead
contamination from sterling silver/gold.

I am a bench jeweler specializing in restoration and I come across
"lead solder contamination" more often than I would like to.

I researched your archives; however, I either did not know how to
successfully research them, or I typed in the wrong wording of my
question. so that is why I am sending you this email.

Can you refer me to some books/magazines/etc.

Thank you
Susan

susan,

I have done alot of restoration work, and yeah, this is a common
thing…I really wish people would not lead solder their jewelry…

I hate to inform you that lead contaminates gold and kinda seeps into
it…and the only way I know how to deal with it is to cut it out,
and restore the section. at least this is the only way I have
discovered to deal with the issue. sorry.

-justine

I find soaking the articles in “Muriatic Acid” eats the lead. It’s
used for cleaning bricks and can be bought at hardware stores and
Home Depot. Nasty stuff. Get good ventilation or outside.

David Geller
JewelerProfit, Inc.
510 Sutters Point
Atlanta, GA. 30328
(404) 255-9565 Voice
(404) 252-9835 Fax
david@JewelerProfit.com

I am desperately trying to find any articles on "removal of lead
contamination from sterling silver/gold

Dear Susan,

Page 71 of Tim McCreight’s book on The Complete Metalsmith, there
is a chemical formula for removing soft solder. I haven’t used it,
but I will quote what it says for you in hopes to be helpful.

  Lead/tin alloys such as soft solder will create pits in gold,
  silver, copper or brass when heated above 260 degrees C (500
  degrees F). Where scraping or filing won't work to remove
  white metals that have accidentally adhered to a workpiece,
  soft solder can be chemically removed. 

            Mix 3 oz. glacial acetic acid with
            1 oz. hydrogen peroxide.
            Heat but do not boil.

  Brush onto the affected area and allow several days to work.
  Tin will be left as a white powder that can be brushed off. 

Good luck, and regards,

ekrem.

The last I read was NOT to heat lead soldier on gold as it forms an
alloy that must be refined to seperate. If it were me, I would scrap
and or sand the pieece until I was sure I was at bare metal.

mike

I have been successful in removing lead solder from sterling by
soaking it overnight in muriatic acid.It leaves pits and holes where
the lead had alloyed with the silver. I do not know the chemistry of
this but it sees to work

strammy

Hello Susan,

You ask about removing lead from silver and gold articles. Well part
of my living is made from antique restoration work. Many of the
pieces I get to restore have been contaminated with amatuer
repairers who use lead solders. I am not sure what is available
where you live, but over here in the UK we can buy a drain cleaner,
called “Spirits of Salts”, it is a hydrocloric acid and water based
solution. This solution dissolves lead and turns it into powder in
minutes, or if you make the solution weaker by adding more water it
will do the same job ,but gentler and slower, (better for delcate
jobs with stones and enamels), a weak solution will work overnight.
Wash of the acid and soapy brush will finish the job. remember for
your own safety always wear rubber gloves and eye protectors when
working with acid based products. I hope this is of help to you

James

   I find soaking the articles in "Muriatic Acid" eats the lead.
It's used for cleaning bricks and can be bought at hardware stores
and Home Depot. Nasty stuff. Get good ventilation or outside. 

that’s been my experience too. Muriatic is dilute Hydrochloric.
Leaves a “smutty” surface on silver (silver chloride) which can be
removed with light brushing or buffing. Lead and tin based solders
(not all soft solders used with jewelry have lead. electronics
solders are lead, but some of the low melting types, sometimes
called silver solders (a small amount of silver in basically a tin
based solder) are mostly tin, and may have bismuth, or other various
exotic componants. Most are mainly tin, though, which etches nicely
in HCl, (muriatic) The solders tend to slightly penetrate the gold
or silver, but the keyword is slightly. After acid etching, you’ll
want to lightly abrade the surface, perhaps with just a wire brush,
or the 3m radial bristle disk type products, until the metal is again
the right color (gold or silver) without the dark stain left by the
soft solder. A brief dip back in the acid will then show if it’s all
gone, since if not, it will discolor again. Don’t proceed to "hard"
or higher temperature soldering methods until the lead or tin based
mess is fully gone. In many cases, you can greatly speed up the
whole thing by using a scraper (triangular machinists scraper is
ideal) to remove the bulk of the thickness of the solder before
etching. The solders are so much softer than the silver or gold or
copper based metals that it’s easy to tell when your cutting the
solder versus when you’ve scraped down to the underlying good metal.

Peter

    I am desperately trying to find any articles on "removal of
lead contamination from sterling silver/gold. 

Hello Susan;

Among other things, I am also doing a lot of restoration. I often
encounter lead solder. Here’s what I do. First, scrape away all the
lead you can get at. It’s soft enough that you can remove it quite
quickly before you get down to the metal below. With gold articles,
I then leave them in a dilute solution of hydrochloric acid for a
while, checking them occasionally. I often need to wire brush away
the dark smut that the lead leaves behind. Never heat the article, or
if you do, make sure you don’t get it even close to the melting
temperature of the lead, as it will eat it’s way into the metal,
gold, silver, or otherwise. Not much short of aqua regia that will
affect the gold, but sterling can be affected by most acids, to
varying degrees. You can also use ferric chloride, but keep an eye on
it if it’s silver. Better to use sodium bisulphate or citric acid on
silver. Still, monitor the effects of the acid. Nothing is a
substitute for careful physical removal of lead. The scraper or bur
can be quite dull, dull enough not to bite into the gold or silver,
and still effectively, albeit slowly, remove the lead.

David L. Huffman

Susan,

the only way i know to completely remove lead from gold or silver is
with straight muratic acid. you can find it at a your local hardware
store or a pool supply place. DO NOT TOUCH IT. IT IS DANGERIOUS! let
is soak for 24 hrs then check it. use a copper tong to put it in and
take out.

Matthew
mhgjewelry.com

Hi Susan,

Presuming the piece is gold & there are no stones or ones that could
take this chemical–we soak for a few hours to overnite in a small
container with hydrochloric acid…Meaning, if the piece can fit in a
container that can be sealed and submersed in the solution…We do
this also with broken drill bits stuck in a piece that is being
drilled…Look in a hardware store, check over concrete etching
solutions–also known as Muriatic acid… and use precautions/follow
directions in handling… Alot of times this will be an over the
counter hdro. acid. at 20 degrees…This should strip off the lead and
leave the gold alone… We have even done this in a localized area on
a gold plated chalice that was silver underneath and was several
hundred years old.Of course, in this case we checked this over every
15 minutes…BE CAREFUL and use gloves that are for chemical useage/
eye protection and do it in a ventilated area…If you choose to sand
instead, remeber to wear a respirator/mask because of the lead
particles in the air…

Good luck!!
Sincerely, Jo-Ann & John Donivan San Francisco, Ca

 we soak  for a few hours to overnite in a small container with
hydrochloric acid... 

In the UK you can get hydrochloric acid at a chemist’s by the name
of Spirits of Salts - usually for patio/concrete cleaning.

Pat

Heres another formula for you to remove lead solder that I use it
works very quickly, so if time is important it can be very useful,
although you have to prepare and bottle the liquid I find its well
worth the effort. Do it out side or with good ventilation, rubber
gloves and eye protection. Here it is:

    4 parts Ferric Chloride
    1/2 part Hydrochloric acid

Boil, immerse the article (provided that it contains no stones with
the exception of diamonds). Remove and brush occasionally

Regards
Colin Waylett (Spain)