This is a series of hanging light-catchers made for Wildcare Australia, a wildlife rehabilitation organisation.
As they are a fundraiser, I need to be able to punch them out quickly and easily.
Have made an alumina hydrate/plaster 'hump' mould. ie the mould is laid on a textured sand bed and the 8mm float glass slumped over the mould.
I feel that I can probable get several firings from the mould with careful handling.
With the Humpback whale, the fins and flukes broke off when the mould was removed from the RTV master.
The problem with the hump mould is that there is not enough thickness to prevent cracking, and not enough depth to easily introduce reinforcement. I also think a combination of mould fragility at slumping temperature and the movement of glass causes the cracking as some of the fired moulds have clearly moved with the glass. The green strength, or lack of, contributed to problems removing the mould from the master.
Fired another batch with various reinforcements. Used fibreglass and aluminium insect screen mesh and linked paper clips. In addition I added 10% cement to improve green strength.These reinforced 10% cement moulds fared better and survived 2 firings. Further research into mould mixes needed.
