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craigb
10th Feb 2005, 02:21 PM
O.K, here's a question for you metal fanciers :)

Say you've built yourself a furnace, and decided that you wanted to have a stab at making some bronze.

Where do you go to buy your supply of copper and tin?

Is there some place that will sell you say 50kg of copper and 30kg of tin? Or is the minimum purchase a tonne? :eek:

I have no intention of ever doing this, I'm just curious. :)

silentC
10th Feb 2005, 03:05 PM
Haven't tried myself, you understand, but I've read postings on other forums (yes I do see other people) that talk about buying stuff in ingots from metal suppliers. Then there's the recycling depot (aka the tip). These days they sort the scap metal, so if you know what you're after, you can scavenge bits of copper, brass, aluminium, steel etc. The latter is a bit more interesting because you never really know what it is you've got. Apparently this can lead to exciting results come melting time.

ozwinner
10th Feb 2005, 07:06 PM
You want pewter, Ive got heaps of pewter tankards.

I keep thinking I should melt them down and make something with them.

Al :)

Christopha
10th Feb 2005, 07:58 PM
Hey, Big Al, you don't exactly need a furnace for pewter mate., it melts at about the same temp as solder..... stick it in an old pot over the gas stove but make sure you have the exhaust fan on......... :eek:
A couple of years ago I did an arty farty bronze casting workshop which was related to our local little festival. We cast bronze into forms we made carved from cuttlefish. The bronze was just all sorts of offcuts, castoffs etc from a foundry and we melted it in crucibles using oxy gear. I turned out a few bits and pieces that were not too bad for a left handed epileptic on a bad day.

ozwinner
10th Feb 2005, 08:20 PM
A pewter hat........:p

Al :D

journeyman Mick
10th Feb 2005, 08:22 PM
............... I turned out a few bits and pieces that were not too bad for a left handed epileptic on a bad day.

I'm sorry to hear of your afflictions Christopha. :eek: :p :D

Mick

echnidna
10th Feb 2005, 08:36 PM
A pewter hat........:p

Al :D

Coming Soon
Al's Everlasting Pewter Foiley's

craigb
10th Feb 2005, 08:59 PM
Well these are all good responses, but I'm interested in how you do it from first principles.

That is, here is a lump of pure copper, and here's is a lump of pure tin.

(Not some manky old crap that you've found at the town dump Darren.)

I mean, it doesn't get much more basic than that.

If peoples weren't able to do it 3500 years ago, we wouldn't be having this conversation now.

Call yourselves metalworkers, phaw :) :) :D :D

bsrlee
11th Feb 2005, 12:23 AM
Well 50Cu-30Sn is a pretty poor alloy actually - it was used in the 'middle East' for run of the mill, low detail stuff, but it is pretty brittle & a lot of the stuff that is dug up is broken already. IIRC anything with more than 10Sn is considered 'High Tin alloy' and is hard & brittle.

You would be better of with say 95Cu-05Sn, which is fairly corrosion resistant & malleable - it was the preferred alloy for gun founding. Or you could go 05Cu-95Sn, which is proper pewter (actually up to 10Cu, but it starts to look 'brassy') - the stuff with lead in it would get you dragged through the city by the Pewterer's Guild, Pilloried & you 'mark' defaced if you got caught.

I think there is a bit of art involved in getting the alloy to be uniform, and various fluxes were used to remove any oxides & dead animals from the melt. These days you would probably be better off buying a pre-made alloy in pellet form, rather than making your own.

If you were going to make your own, or buy ready mix, just look up 'non ferrous' in the Yellow Pages. Someone like Austral Crane Bronze (or whatever they are called these days) would then sell you about a tonne of metal in pellets (which are easier to weigh & melt) or bar.

Of course if you want to get REAL authentic, then you use Arsenic instead of Tin - it took a few hundred years (and a few hundred foundry men) before they worked out that Tin was a suitable metal for alloying. Just as well there wasn't Workcover a few thousand years ago.

craigb
11th Feb 2005, 09:52 AM
Well 50Cu-30Sn is a pretty poor alloy actually - it was used in the 'middle East' for run of the mill, low detail stuff, but it is pretty brittle & a lot of the stuff that is dug up is broken already. IIRC anything with more than 10Sn is considered 'High Tin alloy' and is hard & brittle.

You would be better of with say 95Cu-05Sn, which is fairly corrosion resistant & malleable - it was the preferred alloy for gun founding. Or you could go 05Cu-95Sn, which is proper pewter (actually up to 10Cu, but it starts to look 'brassy') - the stuff with lead in it would get you dragged through the city by the Pewterer's Guild, Pilloried & you 'mark' defaced if you got caught.

I think there is a bit of art involved in getting the alloy to be uniform, and various fluxes were used to remove any oxides & dead animals from the melt. These days you would probably be better off buying a pre-made alloy in pellet form, rather than making your own.

If you were going to make your own, or buy ready mix, just look up 'non ferrous' in the Yellow Pages. Someone like Austral Crane Bronze (or whatever they are called these days) would then sell you about a tonne of metal in pellets (which are easier to weigh & melt) or bar.

Of course if you want to get REAL authentic, then you use Arsenic instead of Tin - it took a few hundred years (and a few hundred foundry men) before they worked out that Tin was a suitable metal for alloying. Just as well there wasn't Workcover a few thousand years ago.

Thanks bsrlee (can I call you bsr for short? :D )

Is it the amount of copper that determines the colour of bronze?

I mean bronze statues (even unweathered ones) are a totally differnt colour to the bronze used in a Lie-Nielson plane for instance.

Cheers
Craig