leaded bronze?

[MRA]

hi folks

I've a little of what I *think* is pure tin, so I'm going to have a go at making bronze. Pure tin seems tricky to get hold of and expensive, whereas various alloys called 'pewter' seem easier to find and cheaper - and are very largely tin.

So...what about mixing about 85-90% copper and 10-15% 'pewter'? If it's tin + lead, this seems to suggest the result of bronze with a bit of lead in it - which seems to be something one can buy with claims of reasonable wear properties etc.

I might add that being resourceful and experimenting means rather more to me than knowing 100% that I'm going to end up with an alloy I could sell to Rolls Royce.

cheers
Mark

 

[abby]

MRA where are you ? your reference to RR suggests the UK ?
If you are in the UK I can supply you with pure (99.75%) Tin.
I use it for making gun-metal.

 

[bazmak]

metalurgists have been experimenting with metal alloys since the dawn of man
i assume most have been tried one time or other,so you are no different
So go for it.Pewter and copper with maybe some alum should give a bronze alloy so give it try keep us up to date,i should imagine you will get many comments/interest with this post. Regards Barry

 

[MRA]

Thanks for your encouragement Barry, and yes, Abby, I'm in the UK. Outside of the small amount I acquired 2nd hand, I've not found a supplier for pure tin before - how much does it cost? Pewter seems to be £20-ish a kilo at the moment, plus I guess scrap pewter comes along from time to time - tin, not so much.

My set-up is pretty small - I'm melting less than a pint (including the head ) at a time.

 

[abby]

MRA I have sent you a pm with details.

 

[tjwal]

Some lead free solders are almost pure tin.

 

[kiwi2]

"Some lead free solders are almost pure tin."

I thought that was one of the things which went wrong with Scott's Antarctic expedition. His canned goods were soldered with tin which went through a phase change at the low temperatures prevailing, became brittle and the cans failed.

 

[abby]

It is also legend that a Russian Czar invested heavily in tin and several hundred tonnes were stored in the cellars of the Kremlin , this suffered the same fate and finished up at the end of winter as a grey dust.

 

[tjwal]

Lead free solder for the electronics industry is about 95% tin with a bit of silver and copper thrown in. I've got 2x5 lb rolls that I want to alloy with some scrap copper but I want to upgrade my furnace and get a real crucible first though. My planned project isn't engine related, its a Greek helmet and dagger. As long as I can get as good of alloy as they could 3000 years ago, I should be ok.

 

[abby]

I spent much of my working life casting sculptures and parts for restoration of antiques so bronze has been a topic of great interest to me.
In particular the colours of the patinas that can be obtained is worth much study.
One of my favourites is a Japanese bronze which is 25% lead the remainder being copper , no tin at all !
To make this alloy requires a minimum of 3 melts , on solidifying , liquid lead oozes from the ingot and when cooled the whole needs remelting and mixing.
With each melt and pour a little less lead is rejected until finally the alloy is complete.
A deep orange patina can be achieved with this alloy.
I would advise that care should always be taken when melting metals as , even if not immediately apparent , toxic amounts can be airborne around the furnace area.
I always wear a respirator , very sweaty and uncomfortable but better to be safe.
Even handling some metals can contaminate your hands enough to poison any food you might consume ....... enter the Cornish pasty lol!