I basically made something very similar to these: http://www.bestvaluevacs.com/aluminumchambers.html

I bought an aluminium soup pan of 20 litres (do not use steel as it is too thin, alu is generally 3-4mm thick and will hold under vacuum), and a 1" thick slab of perspex. I used my dremel to rout a 2 mm deep circular depression in the perspex (using a 3d printed jig) and poured a hard silicone gasket into that. I bought a vacuum manometer and taps/fittings from aliexpress, as well as this vacuum pump: http://www.aliexpress.com/store/prod...858307655.html

I then added a 70W silicone heating strip and a temperature controller that I taped to the outside of the soup kettle with kapton tape and then put a layer of glass wool isolation around it all:

diy_vac.jpg

It works really well. The pump will create a vacuum well below 100 mbar. At first it struggles, but as the water is depleted the vacuum drops slowly to nearly 50 mbar. The aluminium soup pan holds up well and does not crumple under the deep vacuum (as a stainless steel pan will do,guess how I found out...).