Anders
I suspect borax was not used before the medieval period. If I remember correctly, the sources of borax are USA and India. Although it was mentioned in the Mappae Clavicula (9-12 centuries AD), it is thought there to have been natron or argol (wine lees ie tartrate). But boron is notoriously difficult to detect (eg by XRF or SEM). There are other salts suitable for fluxing at high temperatures, eg potash from plants.
Vanessa
-----Original Message-----
From: Arch-Metals Group [mailto:[log in to unmask]] On Behalf Of Anders Söderberg
Sent: 14 August 2006 11:23
To: [log in to unmask]
Subject: Re: Resin as flux
Thanks!
When do You think borax may have been introduced as a flux in Europe?
I've seen Medieval crucibles from Sweden (12th century and onwards) looking like the've been heavily exposed to some very potent flux (borax?) in the melting process, and sometimes even i n s i d e the crucibles which I think is important here. When studying Viking crucibles (pre 1050-1100) I don't necessary find those characteristics.
I've just been a week at the Experimental Arch. Center at Lejre, Denmark, trying different fluxes in casting-on molten silver on solid silver, together with a colleague. Sometimes with amazing results. Sometimes failing.
Anders
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