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Old 07-09-2018, 08:20 PM
Dave Bross Dave Bross is offline
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Second what Jordan said.

Tin also speeds up the set time radically which makes it anywhere from a bitch to work to impossible as it sets before you make it to the marver.

Changing set point/time changes compatibility so this throws off the matching characteristics too and you're back to figuring out what it would take to match it.

If you're going to try it use phosphoric acid for the phosphorous and be damn careful with it. It carries the least oxygen of any source I could find so less black tin would be needed.

I haven't tried this, just thought about it, and there would probably be a VERY violent reaction mixing an acid with all that alkalai in prepared batch so perhaps soaking it into the sand first and drying it out like you would a gold ruby would be the way to go.

You can buy phosphoric acid on Ebay in 80-some percent solution.

The crucibles you linked to are assay crucibles. You can buy them much less expensively. Hit the search engine here for the actual sources and what you need to know about shipping them.

Lose the Borax and add more nitrate if you want it to melt faster and be less trouble. Recalculation will be necessary of course.
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Last edited by Dave Bross; 07-09-2018 at 08:27 PM.
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