I have a big silicone cloche mould I want to fill with Isomalt and I want it to be hollow.  So far I have attempted it about 10 times and I'm left with really big air bubbles in my piece. if I try to blow torch it out my mould warps and melts. what can I do to stop these forming? and is there a way I can make my Isomalt really thick so I can blow torch without melting it?

At the moment I have been filling my mould to the top, leaving it for half hour then tipping the residual out. Should I be greasing my mould first?  Please help!!!

Sorry, I have never used Isomalt.  Would it help eliminate air bubbles if you gently ran a skewer through the Isomalt as it starts to set up, before it gets hard, to burst some of the air bubbles?

When I've used isomalt, after it has boiled, I leave it for a few minutes to let the bubbles dissipate before pouring it. Maybe resting before pouring would help? Since it's silicone, I don't think it needs greasing.