Proportions are not really right. for quality bearing so depends how critical it is.

Some old pewter has lead which may not be what you want and from what I've seen pewter doesn't have as much Cu or Antimony (Sb) as true babbitt…

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A good source of pure tin is lead free solder and so you could try your own Sn/Cu mix by melting some tin and chucking in enough copper filings? Antimony is a bit more tricky.

HTH

Jon

Not quite that simple – you need to make sure that the various metals all dissolve together, with no 'filings' or other bits left undissolved. This can take time at temperature, and meanwhile oxidation is producing scum or dross, which removes some of the metal (but not in proportion) from the mix.

It can be done, but if it were simple there would be no point in the various off-the-shelf suppliers (who have all gone down the plug-hole of fate, muttering 'bloody lead indium' as they went).

Cheers, Tim

Your point's well made because of the high melting point of the copper (almost 1100 degrees C) and the difference from antimony at 630 and tin at only 230.

…but my guess is that the most deterioration will be to the tin and antimony. So, if you heat a generous amount of tin and antimony with the minimum amount of copper you may get close to a usable alloy for a one-off. All of the metals are fairly stable. But then the mixture needs to get to and stay above 1100 degrees for long enough to melt the copper and get it to mix. The 3 metals all have very similar density 6-8 g/cm^3 and so convection currents in the melt are likely to do the mixing ok with a quick stir.

I think it'd be worth a go for a one-off.

Jon

Edited By Jon Gibbs on 25/02/2016 18:17:42

It depends on how critical your application is. With lower speeds and a low load application, coupled with maintaining a good film of lubrication, you may get away when trying to alloy the materials yourself.

The widely varying melting temperatures of each of the alloys in producing the final alloy can very easily lead to a none homogeneous structure of the resultant alloy which will give premature failure.

Probably the two most used tin base alloys used ( in the UK ) are BS3332/A ( preferred for centrifugal casting ) and BS3332/C ( preferred for static casting. Both suitable for high speed and high loading applications. Then BS3332/F for lead based applications.

Cadmium and to some extent silver was used in quite a few alloys to "stiffen" up bearings on high loads but Cadmium has thankfully been  phased out because of its high toxicity.

Edited By MalcB on 25/02/2016 21:26:47

Yes, Neil, some copper will dissolve. But you won't know how much – and it won't be any good weighing the copper before and after because the 'pewter' will stick to it.

Cheers, Tim

Edited By Tim Stevens on 26/02/2016 16:40:45

You could, I suppose, try copper oxide in powder form, and maintain a reducing atmosphere, but I am not sure how hot that would need to be to complete the reaction. But not copper sulphate, Ady1, as the 'other bit' would produce sulphuric acid fumes (or sulphur dioxide and trioxide, just as bad).

Cheers, Tim

As you said, Ady1, you are not a chemist. I was thinking mainly of the effect of concentrated acid fumes on the other metals in the pot, and any other tools which happened to be within fuming distance.

Tim

Well said!

I will stick to ready made as well.

Geoff – Head cold stopped all worthwhile play