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Longwood
03-16-2011, 06:20 PM
I stopped into a thrift store today and bought one piece of pewter and another I think may be pewter that is silver over copper plated. It is a non magnetic oval tray about 10" X 7" and is 3/16" thick and weighs 1.1 pounds. If it is pewter with copper and silver plateing will it alloy with lead or will the silver and copper float to the top? I know some pewter contains a small percent of copper but do not know if it will alloy without a special flux.
How can one tell if a piece is made of pewter if nothing is written on the piece?
Thanks for your replies.

versifier
03-16-2011, 07:40 PM
The most common things that get confused with pewter are zinc and aluminum. The amounts of copper and/or silver in the pewter are so small that they don't have any real effect. I've used up lots of damaged pewter as a tin source, never had a problem, and I have a stash of pewter ingots. The best way to tell what it is: see what it takes to melt it. If you've passed 800* and it's still solid, it's aluminim or zinc. Like pewter, aluminum is very soft and scratches easily, zinc is not and doesn't. If it's fairly old pewter, it may have a good percentage of lead in it, in which case it will leave a line on a sheet of white paper. I have never seen or heard of plated pewter, but who knows what's out there. Silver is often plated over copper onto a brass base though.

badbobgerman
03-16-2011, 10:08 PM
are license plate metal frames zinc? it takes a lot to melt them .. trying to make zinc ingots from sources of ww's and dont want to mix my metals up ...,, ps i too have a difficult time telling pewter from aluminum and zinc ill try the melting temp method also zinc will not mix well at a 50/50 concentrate of lead zinc so if it is oatmeal like it has zinc just mix an ounce of each with a torch

Longwood
03-17-2011, 01:46 AM
The most common things that get confused with pewter are zinc and aluminum. The amounts of copper and/or silver in the pewter are so small that they don't have any real effect. I've used up lots of damaged pewter as a tin source, never had a problem, and I have a stash of pewter ingots. The best way to tell what it is: see what it takes to melt it. If you've passed 800* and it's still solid, it's aluminim or zinc. Like pewter, aluminum is very soft and scratches easily, zinc is not and doesn't. If it's fairly old pewter, it may have a good percentage of lead in it, in which case it will leave a line on a sheet of white paper. I have never seen or heard of plated pewter, but who knows what's out there. Silver is often plated over copper onto a brass base though.

Thanks for that.
It is way too heavy to be aluminum. I checked wikipedia and they did plate pewter with silver it seems so I guess I will just have to melt it and see.

versifier
03-17-2011, 06:44 AM
baddbobgerman,
I don't know, I have only had one smelterful of WW's get contaminated by zinc. I got a phone call and missed the crucial point when the clips rose in the melt with the zinc weights. No good for casting and I disposed of it. When in doubt I just toss any suspected WW's - if I have time, I try a scratch test, but mostly I just look for riveted clips.

badbobgerman
03-17-2011, 06:37 PM
baddbobgerman,
I don't know, I have only had one smelterful of WW's get contaminated by zinc. I got a phone call and missed the crucial point when the clips rose in the melt with the zinc weights. No good for casting and I disposed of it. When in doubt I just toss any suspected WW's - if I have time, I try a scratch test, but mostly I just look for riveted clips.

use a pair of pliars or a sidecutter the lead will dent or mash down the zinc will scratch only the paint , some zinc will not have a rivet... most "fe" or iron , wil be riveted...... good shootin

fryboy
03-30-2011, 06:46 PM
some items such as teapots, sugar bowls and creamers can indeed be silver plated tin/pewter , the bend test comes to mind , pure tin has it's own unique "shriek" when bent , various pewters alloyed with copper, antimony and even lead of course all help mute this shriek , alot of the more modern stuff is often plated zinc - it wont bend for umm very easy and often will break , real pewter on the other hand bends even easier than aluminum , there is at least one company who states that they use a lil bit of silver in their cast boolits , IMHO it helps a bit with fill out and malleability , it just isnt economical to use ( especially with the silver prices lately ) i like to melt each piece down separately , once it's passed the heat melt test it's usually ok to mix it with other known good pewter , pewter melts at 440 - 470 degrees and dosnt react to hydrochloric acid the way zinc would
here's a couple of good links for further reading

http://www.princeaugust.ie/alloys/

http://www.ramshornstudio.com/pewter.htm

Firefly1957
04-01-2011, 05:22 AM
I have a very old piece that broke it states silver plated I attempted to solder it with 60-40 solder and the core melted before the solder? It must be tin with the weight and low melting point but will break if bent about 20 degrees? (it is/was a complicated candle holder that held a crucifix the cross is silver there is no country of origin on it)