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Stefflus

Tin and Pewter, annealing temp relative to melting temp?

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Many different alloys involved in this question, but it is doable to find the melting temperature for each.

-Could the annealing temperature be expressed as a constant relative to these melting temperatures?

-Do these even need annealing, do they work harden?

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That is a rather open question. As you say, many alloys involved. From my experience, annealing pewter is not nessesary. I have worked small diameter pewter very far without annealing. At some point it will harden up. It does not work harden like copper alloys in that copper hardens as you work it. Pewter will all of a sudden start to harden after it has been worked for a while. I have never forged tin. With a melting point of about 425 Deg. F and being very soft, I have not had the need....

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As I recall the dislocation climb temp for traditional pewter is below room temperature; so if you manage to workharden it, leave it alone for a while and it will soften back up.  Of course this is *extremely* alloy dependent

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Thanks fellas!

 

60% translates to about 30C, so I could just hold it in my hand for a while or put it in the oven at 50C.

I was fearing I would have to be living on the edge, real close to the melting temp..

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I made a pewter billet approx. 1/2"x1/2" by 8", and forged it a bit just to see how it behaved. (Working in the house since it's winter and I have smithing itch, so I'm gonna hammer it down to 1/8" or so, then draw it into wire).

The raw material (a pair of spoons) forged happily when cold, but the billet didn't, it wanted to crack. Poured myself a mug of hot water, and used this as a "forge", but still cracking. Is this a large-dendrite issue?

Based on my hunch, I remelted and poured a new billet, this time dunking it in water just as it solidified. Also I'm heating it over a candle to approx 100 C +. This works well, but obviously I changed two variables at once.

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Just spitballing a thought here, could this conceivably be used as a way to practice forging technique with real metal (vs clay/plasticene) without lighting up the forge? Bang away on a piece to practice xyz skill until the stock is too small or mangled to be of any use, maybe take some pics to document progress, then bang it into a lump to fit into a pot, remelt and cast into an oversized bar ingot, forge down by a third to refine the grain (if thats the right ratio I'm recalling and that still works on pewter at room temp, it that needs to be done hot it could be saved up and done later) until you get to whatever parent stock you desire, rinse and repeat.

Do the lead free pewter's behave the same way? Don't know very much about pewter so my apologies if that's all just stupid on the face of it =\

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Chinobi, I'm guessing it's lead free I'm dabbling with in this case, since it's not very old, and it used to be salad sporks. I'm being hygienic about it tho, just in case.

And it's so much better than plasticene for practice! Plasticene has friction against the anvil surface, and that really messes up practicing with a hammer. Only drawback with tin/pewter is it's not practical to localize heat to make an upset.

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I was thinking that would still be a problem, the whole bar would act as if it was at forging temp, can't work with differential heat =

Maybe instead of using a forge to heat the work zone use something else to chill the remainder of the bar :)

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This is a really exciting idea you've come up with! This could be used to demostrate (some of) the basic forging techiniques at venues which won't allow fire.

 

Thank you!!

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