From time to time I get calls from people who want help or advice about glass. Recently I helped a COFA student realise some pieces for her Honours submission and it was interesting to see someone listen to good advice and then go her own way....
This past week I have been more fulfilled helping Dr Philip Boughton and his Biomedical Engineering team at the Sydney University School of Aerospace, Mechanical and Mechatronic Engineering. Wow!!
They needed someone to make BioGlass 45S5 because they could not use the facilities at the university, or rather there was too much bureaucracy involved. I suspect OH&S and costs were the problems.
Philip came round and dropped off the $16,000 Platinum crucible, some pellets of the material (45% SiO2, 24.5% NaO2, 24.5% CaO and 6% P2O5) and a firing schedule (3 hours to 900 degrees C, 2 hours to 1250, hold for 3 hours and kiln off). With only one crucible this is not the most cost effective method so for the fourth firing I tried ceramic fibre dams and a ceramic mould.
I thought it might not work with the moulds and I was right - they collapsed into a porcelain like form and the glass fused into the mould. The ceramic fibre held up but the glass leaked out and fused to the kiln shelf through the ceramic fibre base. Not so good but worse still a third of the kiln's heating elements no longer work. All in all a good experiment but with disastrous results!!
Now I need a kiln service technician to fix the roof elements and we must think of where we can source some ceramic crucibles that will withstand the high temperatures. I did fire glass last night using the side elements only so can still keep production going for my sales and commissions.
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