SidS

Hi, all!
As I have promised you, I've done an experiment using four coins threepence, different years, to cover all four compositions. I have tried to have relatively similar initial weight and grade.

I have rubbed them on seven rounds, applying the same treatment for all of them, the same finger pressure and the same number of up-down courses, using sand paper 40 grit for Round 1, 100 grit for Round 2-3 and 220 grit for Round 4-7. 
Of course, because I have not specific tools to measure the pressure and very accurate scale, this experiment it is not a very scientific one and my results are only pseudoscientific. But it is better than nothing. I have weighted three times every coin, and the recorded and valid weight was an average or the weight showed by scale two times. The recorded weight can be a little different than in pictures, with a difference of +/- 0.01g.
The coins used for this experiment are below, with pictures before and after:
1. 1917, 0.925 silver, 0.075 copper, weight initial 1.43g, final 1.23g, losing 0.20g.
 


 
2. 1921, 0.500 silver, 0.400 copper, 0.100 nickel. Initial weight 1.40g, final weight 1.19g, losing 0.21g


 
3. 1925, 0.500 silver, 0.500 copper. Initial weight 1.41g, final 1.20g, losing 0.21g.


 
4. 1936, 0.500 silver, 0.400 copper, 0.050 nickel, 0.050 zinc. Initial weight 1.40g, final 1.15g, losing 0.25g.


 
The initial, intermediary and final weights and total loss of these four coins are recorded in this chart:

The pictures are not great, but I've done the best I was able.
Conclusions:
In term of resistance,
0.925Ag/0.075Cu alloy lost less, 0.20g, but what is interesting, is almost blank now, unrecognizable.
0.500Ag/0.400Cu/0.050Ni/0.050Zn alloy lost 0.25g, apparently the worst, but again it is interesting, it is not blank, still having some details.
0.500Ag/0.400Cu/0.100Ni and 0.500Ag/0.500Cu lost the same 0.21g. Nothing to add about condition. George V is still there a little, in the mirror.😊
I hope this experiment will be useful for all of us. Can be repeated by another TSF member, having a total cost of @£10 (coins, sand paper),but is time consumer (@3h for me).
All the best!
Stefan.
 
 

Silver from 1920-1946 isn't that straight forward.
1920-1922 it was 50% silver, 40% copper and 10% nickel.
This nickel is responsible for the rather unappealing yellow/mustard toning they get.
From 1922-1926 the nickel was eliminated. So 50% silver and 50% copper.
From 1927-1946 the coins were 50% silver, 40% copper, 5% nickel and 5% zinc (I think it was zinc).
 
Source: Coincraft 2000 catalogue.

Silver from 1920-1946 isn't that straight forward.
1920-1922 it was 50% silver, 40% copper and 10% nickel.
This nickel is responsible for the rather unappealing yellow/mustard toning they get.
From 1922-1926 the nickel was eliminated. So 50% silver and 50% copper.
From 1927-1946 the coins were 50% silver, 40% copper, 5% nickel and 5% zinc (I think it was zinc).
 
Source: Coincraft 2000 catalogue.

Silver from 1920-1946 isn't that straight forward.
1920-1922 it was 50% silver, 40% copper and 10% nickel.
This nickel is responsible for the rather unappealing yellow/mustard toning they get.
From 1922-1926 the nickel was eliminated. So 50% silver and 50% copper.
From 1927-1946 the coins were 50% silver, 40% copper, 5% nickel and 5% zinc (I think it was zinc).
 
Source: Coincraft 2000 catalogue.

Silver from 1920-1946 isn't that straight forward.
1920-1922 it was 50% silver, 40% copper and 10% nickel.
This nickel is responsible for the rather unappealing yellow/mustard toning they get.
From 1922-1926 the nickel was eliminated. So 50% silver and 50% copper.
From 1927-1946 the coins were 50% silver, 40% copper, 5% nickel and 5% zinc (I think it was zinc).
 
Source: Coincraft 2000 catalogue.

We'd be on three in a row, Theresa May was awful. She'd make a good robot though.

I just found it in the nick of time then! 🤣

Looks like 1949 to me!
If you had a 1964 Franklin I'd be interested!

I feel your pain!

I've always used beat up coins for pocket pieces, I think it'd hurt inside to put a shiny in (even a bullion piece!)
😁

Maybe it's time I revived the tradition. Maybe a Mercury dime or something.
I wish I still had those worn early 20th Century German 1 Reichsmark pieces I used to have, they would have been good.
When I sold off the half guinea and halfcrown I had, I did carry an awfully battered 1945 florin for a number of years, that's still around somewhere.

I concur!

I used to carry two coins around with me a long time ago.
A worn and counter-stamped William III halfcrown (1697) and a gold half guinea of Charles II which was so worn you could only tell what it was by the edge of the bottom of his bust and on the other side the remnants of the odd shield, it was also slightly bent. Cool near blank of gold though.

Perhaps because it didn't really crash, they brought it in for a rough landing on a few bubbles. If they'd actually not intervened at all and let the whole thing come down as market forces would dictate it would have been brutal but much shorter duration. They've just kicked the can down the road and made the next crash bigger and more brutal.

Perhaps because it didn't really crash, they brought it in for a rough landing on a few bubbles. If they'd actually not intervened at all and let the whole thing come down as market forces would dictate it would have been brutal but much shorter duration. They've just kicked the can down the road and made the next crash bigger and more brutal.

Perhaps because it didn't really crash, they brought it in for a rough landing on a few bubbles. If they'd actually not intervened at all and let the whole thing come down as market forces would dictate it would have been brutal but much shorter duration. They've just kicked the can down the road and made the next crash bigger and more brutal.

Perhaps because it didn't really crash, they brought it in for a rough landing on a few bubbles. If they'd actually not intervened at all and let the whole thing come down as market forces would dictate it would have been brutal but much shorter duration. They've just kicked the can down the road and made the next crash bigger and more brutal.

We'd be on three in a row, Theresa May was awful. She'd make a good robot though.

We'd be on three in a row, Theresa May was awful. She'd make a good robot though.

We'd be on three in a row, Theresa May was awful. She'd make a good robot though.

I'm trying to work out what looks more phallic, the red scrawled banana or Scandinavia.

I'm trying to work out what looks more phallic, the red scrawled banana or Scandinavia.

Ironically the post 1947 coinage, although priced the same, is much more difficult to get hold of in UNC condition than the silver.
The brass threepences are even harder.
 

Gorgeous crowns, especially the George III!

You wear underpants 😲