PDA

View Full Version : pewter?



robpete
06-09-2013, 09:20 PM
I was at my family's summer place this weekend and went to a large area flea market. I was on the hunt for pewter.....and shrubs. I scored a bunch of hallmarked stuff, but also picked up a few pieces with zero markings. They are three napkin holders...weighing about 3.5 ounces each. The gentleman insisted that they are pewter. I got him down to $2, so I figured I'd take a chance. How does one tell if a metal is, in fact, pewter?
7310473105

Taylor
06-09-2013, 09:23 PM
I don't think those are pewter,china---could be anything.Normally pewter is marked,and states that it is pewter.

NoZombies
06-09-2013, 10:27 PM
I don't think those are pewter,china---could be anything.Normally pewter is marked,and states that it is pewter.

For food grade pewter, that's correct. For decorative pewter, hallmarks aren't required.

I would try melting some and see how it acts. the decorative grades of pewter vary in composition.

Pakprotector
06-10-2013, 06:08 AM
Today's trivia bit..:) Lead contamination in the pewter stock used to cast the Liberty Bell are the cause of the cracks.
cheers,
Douglas

imashooter2
06-10-2013, 06:12 AM
Melt one of the known pieces and hold it just at liquidus. Break a chunk off one of the unknown pieces and see if it melts into the known alloy. That's close enough for government work.

500MAG
06-10-2013, 06:39 AM
I buy a lot of pewter at flea markets and thrift stores, unless it has the hallmark, I don't buy it. Been burned too many times. Oh, and RWP Wilton Pewter is not pewter. Sellers will swear up and down that it is.

Taylor
06-10-2013, 07:25 AM
Same here,if it don't say pewter....

45-70 Chevroner
06-10-2013, 09:09 AM
I have made cast toy soldiers and I was never able to get any kind of lead to make good filled out casts. I was using rubber molds for the soldiers and the only thing that worked was pewter. Home cast toys will never be marked. I have bought a bunch of toy figurines at our swap meet and they were all pewter, maybe not pure but close enough.

robpete
06-10-2013, 06:37 PM
Melt one of the known pieces and hold it just at liquidus. Break a chunk off one of the unknown pieces and see if it melts into the known alloy. That's close enough for government work.

Great idea! what do you think...about 350-400f?

Iron Mike Golf
06-10-2013, 08:31 PM
Looking at the pic and considering what it's made for and how it's made, I suspect it is aluminum. If I were gonna use a pot, I'd expect it to melt under 450 deg F. First, I'd hit one with a propane torch. If it's pewter, it will melt pretty quickly.

imashooter2
06-10-2013, 09:08 PM
Great idea! what do you think...about 350-400f?

More on the order of 450 - 500 Fahrenheit for full liquidus.

Iron Mike's idea has merit as well, but you can heat small pieces way over 500 pretty quickly with a propane torch.

hickfu
06-10-2013, 11:16 PM
Pakprotector, good fun fact... thanks for sharing.

500MAG, you are correct sir, Wilton (RWP) is an aluminum based metal. those look similar

Hold a torch to one of them, if it melts then its not an aluminum based metal and you may have something.

Doc

303Guy
06-11-2013, 01:02 AM
Has anyone tried measuring electrical conductivity to identify metals?

robpete
06-11-2013, 07:10 AM
I'll do some testing this wekeend and come back when I have some results. Thanks for all of the tips guys.

Centaur 1
06-11-2013, 09:52 AM
If you have a heat gun, use it to try and melt the napkin holders. I've played around with this method and pewter melts easily, fake pewter has a higher melting point than the heat gun can deliver.

Jaak
06-11-2013, 12:59 PM
Scratch it. If it sounds like you are scoring glass then it is pewter.

mroliver77
06-12-2013, 10:24 AM
All pewter was lead based back when the Liberty Bell was cast. From my reading it was a poor bronze alloy with "possibly" too much TIN. It was cast and recast multiple times too without happiness.
J

303Guy
06-14-2013, 04:03 AM
One thing that hasn't been mentioned is density. Measure the density - simply measure the volume of displaced water and work it out. A measuring beaker with calibrations will do. Or fill a jug to overflowing then place a capturing container under the pouring spout and place the sample into the jug and weigh the overflowed water then work out the relative density.

Density of Sn = 7280 kg/m³
Density of Al = 2720 kg/m³

Specific Gravity of Sn = 7.28
Specific Gravity of Al = 2.72 (Varies)
Specific Gravity of water = 1.0

For those who didn't science at school - Specific Gravity is the ratio of density of a substance to the density of water at 4°C (room temperature is close enough).

robpete
06-19-2013, 11:21 PM
I went with the torch method. I held the flame on that sucker for a while. No melt. Oh well. Lesson learned...plus they were only two dollars for all three.

rintinglen
06-20-2013, 01:37 PM
You can always throw them at the neighbor's noisy cat--sorry got woke up at 0200.

robpete
06-20-2013, 09:22 PM
lol. or my neighbor.............