Removing lead solder from gold

Does anyone have any suggestions for removing lead solder from white
gold?

-BK in BWA

Does anyone have any suggestions for removing lead solder from
white gold? 

Get the lead solder molten and wipe it off with a damp sponge.
Repeat. Then use polishing compounds. Paf Dvorak

Hello,

in a chemical way nitric acid will solve lead. A mixture of acetic
acid and hydrogen peroxide (H2O2) in a rate of 80/20 will do the
same.

Take precautions when working with acids (mask, gloves, goggles,
ventilation etc). I’m sure others will have more solutions to help
you out.

Have fun and enjoy
Pedro

I have used Hydrochloric Acid which will not harm the gold but will
dissolve the lead. I think that you can get it at Home depot, it is
used to clean concrete. I would keep an eye on the process as I am
not sure of the affect, if any, on low karat solders.

Good luck, Tim

If the piece has no elements that are heat sensitive, I have done it
this

  1. physically remove all lead solder you can access with burs,
    sanding wheels, files, etc.

  2. make up a batch of pickle specifically for this job, don’t use it
    for any of your other work.

  3. soak it in the pickle for a while, then neutralize the pickle
    with baking soda and water.

  4. remove the residue with wire brushes, scrapers, whatever will
    work]

  5. keep repeating this process until there is no evidence of lead
    solder.

You can use a more concentrated acid, like muriatic, if you’d like,
which may work a little better. I’ve heard oxalic acid works
perticularly well too. Nitric can be used, but take great care with
Nitric, as it is dangerous to handle, it’s very caustic. You can also
accelerate the process by heating the piece, then quenching in the
acid, but take great care not to heat the piece to the point that the
lead solder begins to melt, as it will eat its way into the article
and make a mess.

David L. Huffman

To remove lead solder from any metal, use a copper woven wick, flux
the wick and the metal, heat using a soldering iron on top of the
wick. Continue until there is barely any solder on the metal. Then,
when the solder is more like a stain, burnish the metal until the
solder is completely gone. To burnish you can use a rough eraser,
i.e. typing erase. Then polish the metal.

Veva Bailey

Too often I have encountered lead solder during repairs. Either a
customer has attempted a DIY repair themselves, or a jewelry store
has done a really low quality job.

Either way, before I can do the repair I must remove ALL of the
lead. I start by physically grinding, cutting with gravers, whatever
it takes to remove the bulk of the lead. Once all the lead I can cut
or grind away is removed, I place the piece in nitric acid, and then
remove it and scrape away and darkened areas ( the nitric both
exposes the presence of any remaining lead, and removes some). I
will often rinse the piece, wire brush it, and then test it again
with the nitric acid, to see if any lead at all remains.

Once I see no reaction to the nitric acid at all, I can go ahead and
do the repair correctly. Any lead at all, if I apply the torch at
gold soldering temps, will destroy the gold.

I charge extra for any repairs where lead has been used, explaining
to the customer before they leave their jewelry for the repair that
the lead has made the entire process much more costly and difficult.

I have used Hydrochloric Acid which will not harm the gold but
will dissolve the lead. 

I’m a little surprised at some of the answers to this…
Hydrochloric/muriatic acid is available in any hardware store,
sometimes it’s called concrete etch or cleaner. Read the label. It
dissolves lead and also tin just as nice as you please and doesn’t
affect gold, silver or copper at all. Nitric is a poor second choice
because it doesn’t affect lead nearly as well and it also dissolves
copper and silver. Plus it’s much more dangerous and expensive and
mostly only pros will have it at all. Molten lead will dissolve
right through a piece of jewelry, so I will ~never~ heat a piece with
lead solder on it , though I might also grind away the bulk of it.
Simple chemistry, really.

3 Parts glacial acetic acid mixed with 1 part hydrogen peroxide.
Soaking the item. in this mixture will dissolve lead and tin solders
enough to clean off the remaining traces using scrapers and/or a
stainless wire brush.

The above mixture has no affect on precious alloys, but be
warned…glacial acetic acid is scary stuff. It is very strong as a
liguid, a vapour, and is flammable. Do not allow it to contact your
skin, do not breathe it’s vapours. Use all protecive means including
a fume cupboard.

I prefer to remove lead solders by mechanical means alone. Burs,
scrapers, rubber abrasive wheels, until every trace is gone.

Alastair