Hopefully I'll get to it before it gets much hotter, currently a nice warm 31c (87f?) maximum, so pleasant spring weather, if it gets much hotter I'll have to consider trying to cool the shed a little!

The hotter the better,within reason.your spring time temps are ideal.But do small batches(to keep it watery viscous)and use the high temperatures to help with glass penetration and micro gas release(looks cloudy if trapped).Use just enough to wet the glass so it doesn't float away from the wood and start any epoxy wood sealing with a falling temperature, to suck it in.
All the best.