Vacuum Casting

I have been slowly putting together the essential equipment for this process and now have a workable (just ) system.
Some of my equipment is from the USA, it shouldn't make economic sense to air mail heavy gear to the the UK but it often does - UK suppliers take note, my shopping list includes a kiln and this will probably come from New Mexico and save me 25% - rant over!

Air pressure wax injector, Air is provided by fridge compressor which doubles as vacuum pump.

This unit is 110v so big yellow box just visible is standard UK transformer for building sites etc. The frequency is different, 50Hz as opposed to 60Hz, but heating elements don't care.
Temperature control is excellent but 6 hour warm up time when full of wax means some pre-planning is needed.

Vacuum investing and casting table with casting pad in place, another piece of US kit with it's source proudly displayed.
The plexiglass dome would take 4 of the 2.5 by 3 inch tall flasks I use if I could burn out that many at once!
Fridge compressor takes nearly 3 minutes to pull 27 inches of vacuum so is not really man enough for the job.

Kiln - well actually my mothers old enamelling kiln turned on it's side and controlled by a homebrew setup using a pulse controller from an old pottery kiln.
Temperature control is vital since this thing will go from cold to 1200 C in about 30 minutes flat.
I calibrated the temperature using wax, lead solder, easy silver solder and some pyro cones but the latter are academic since the lowest temp ones are about the highest a burn out needs to go (730 C).

Moulds have so far been done using Ferris see through compound which has to be cured at 150 to 200 C - sort of limits the materials used for masters but they are really easy to cut - can see the model.
If you are going to cure these in the kitchen oven beware, the household authorities will not be amused - smells a little unpleasant.
Takes absolutely ages to vacuum, like 30 to 40 minutes before bubbles die down - possibly due to my feeble vac pump.

Shopping list - well a kiln for sure, the smallest Neycraft unit looks nice and a bigger vacuum pump after that, still baulking at the cost of 3cfm pumps from jewellers suppliers though - suspect air conditioning/ refrigeration companies are a better bet.

First casts - results of using this lot for the first time!