Removing baked enamel from coin
 

"richard schumacher" wrote in message
...
In article . net,
"Jonathan_ATC" wrote:

If it is "real" enamel, which is kiln-fired glass, laquer thinner won't
work.
To remove real enamel, one would have to suspend the coin vertically and
fire in a kiln until the enamel ran off the coin. But, I doubt the OP
has
access to a kiln to do this.

What is the melting point of 90/10 Au/Ag alloy? How does that compare
to kiln firing temperatures?


That said, it could be the same kind of coloring you experienced,
colored
epoxy resin. This COULD be removed by soaking in laquer thinner.

I am a metalsmith as a hobby. I have not worked much in enamel, so last
night at one of our get-togethers I asked some folks who work in enamel for
a living.
Yes, you can suspend the coin in a kiln and heat it to the melting point of
the enamel and it will just drip right off. Just wanted to clear that up
because it was said that would not work. If it is epoxy resin, it will just
burn off.
That said, I was told that the better way was what was described here, heat
it with a torch and quench it and the enamel will pop right off.

As for melting points of silver and coin silver:
Metal Symbol Melting Point ºF Melting Point ºC Specific Gravity Weight in
Troy Ozs/Cu In
Silver, Pure Ag 1761 961 10.49 5.525
Silver, Sterling - 1640 893 10.36 5.457
Silver, Coin - 1615 879 10.31 5.430

That said, most people enamel on Fine silver as it has the higher melting
point. The melting points of various enamel powders vary some by color due
to the additives used to make the colors. However, we know that the enamels
will melt and flow at temperatures lower than .999, .925 & .900 silver
because we've all seen finely enamelled coins.
One such example of these enamelled coins is in the Stacks "The Atlanta
Sale" catalog.

For explanations of different types of enamel and how they are adherred to
coins or other metal, see this site:

http://www.itsmagick.com/M/tech2.htm

I spent 3 hours last night discussing jewelry and coin enamel with people
who do it for a living. Very interesting evening.

Jonathan_ATC

Removing baked enamel from coin
 

"Jonathan_ATC" wrote in message
ink.net...

I am a metalsmith as a hobby. I have not worked much in enamel, so last
night at one of our get-togethers I asked some folks who work in enamel
for
a living.
Yes, you can suspend the coin in a kiln and heat it to the melting point
of
the enamel and it will just drip right off. Just wanted to clear that up
because it was said that would not work. If it is epoxy resin, it will
just
burn off.

That was me who said that.
I am also a metalsmith, and I have sold my enamelled pieces, so I guess I
could claim professional status (though I usually don't.)

I continue to question the "drip off" contention. I reckon that a lot of
enamel would remain within the devices of the coin - and that capillary
action would keep a fair bit on the flat bits.

What do I base this on?

I have, in the past, enamelled dishes on both sides. Picture a small copper
dish - say 3" diameter. Many times I have enamelled the base (the convex
side) then, by carefully suspending the dish above the kiln floor on sharp
ceramic spikes, have managed to enamel the inside, which is now
rightside-up.

None of the enamel on the base has ever "dripped" off, though some will burn
off (over-fire) around the rim.

I still doubt that enamel will run and drip off the piece.
Maybe if you shake it vigorously - not an option within my litle kiln.

I'd still go for the heat-and-quench option, as I said before.

That said, I was told that the better way was what was described here,
heat
it with a torch and quench it and the enamel will pop right off.

Yup.

BTW - either method would leave the poor coin in a sad and sorry state.
I agree with the earlier poster who suggested selling it and buying an
undamaged coin.

Cheers.
--
Jeff R.

Removing baked enamel from coin
 

"Jeff R" wrote in message
u...

"Jonathan_ATC" wrote in message
ink.net...

I am a metalsmith as a hobby. I have not worked much in enamel, so last
night at one of our get-togethers I asked some folks who work in enamel
for
a living.
Yes, you can suspend the coin in a kiln and heat it to the melting point
of
the enamel and it will just drip right off. Just wanted to clear that
up
because it was said that would not work. If it is epoxy resin, it will
just
burn off.

That was me who said that.
I am also a metalsmith, and I have sold my enamelled pieces, so I guess I
could claim professional status (though I usually don't.)

That's cool. I would like to work with enamel, but so far I just work in
silver. My forte is hollow beads about the size of a quarter and about 3/8
inch thick. They sell pretty good. They're nice pieces. I just got a
bunch back from a juried show in a local gallery. But, I would like to
enamel some of them.

I continue to question the "drip off" contention. I reckon that a lot of
enamel would remain within the devices of the coin - and that capillary
action would keep a fair bit on the flat bits.

I figure the same, but was told it would work by several folks last night.
It was just a hypothetical though, no one in the group had actually tried to
get enamel off a coin using the "drip off" method.

What do I base this on?

I have, in the past, enamelled dishes on both sides. Picture a small
copper
dish - say 3" diameter. Many times I have enamelled the base (the convex
side) then, by carefully suspending the dish above the kiln floor on sharp
ceramic spikes, have managed to enamel the inside, which is now
rightside-up.

I've seen dishes like this and wondered why the enamel on one side would not
drip off when doing the other side. I had surmised that the one side has a
higher melting temperature once fired than the second side has when fired.
Am I close?

None of the enamel on the base has ever "dripped" off, though some will
burn
off (over-fire) around the rim.

I still doubt that enamel will run and drip off the piece.
Maybe if you shake it vigorously - not an option within my litle kiln.

Yes, shaking it vigorously is not really an option. Hahaha!

I'd still go for the heat-and-quench option, as I said before.

That said, I was told that the better way was what was described here,
heat
it with a torch and quench it and the enamel will pop right off.

Yup.

BTW - either method would leave the poor coin in a sad and sorry state.
I agree with the earlier poster who suggested selling it and buying an
undamaged coin.

I agree. I don't know why the OP would want to get the enamel off unless it
was a really valuable coin once it was off. I have not had the chance to
examine an enamelled coin up close, especially one AFTER the enamel has been
removed. I would think the surface underneath would not be real nice.

Cheers.
--
Jeff R.

Best regards,

Jonathan_ATC

P.S. I, in no way, meant to state I was an expert in enamel.