Years ago I had an uncontrolled warming cabinet made from a 40W incandescent light bulb inside an old chest freezer, but I decided that the time had come to speak of many things replace it with something better. So, off to Amazon/Ebay/one of those places I went, to order a 40W greenhouse tube heater. Importantly, one with no temperature limiter that wouldn’t allow the heater beyond the manufacturer’s idea of a sensible limit.
The rest of this project is made from stuff I had about the place already.
The first job was to make up a box from 12mm ply that was the right size to sit two national supers on top side-by-side (to keep them warm prior to extraction), so 920mm x 460mm basically. The depth of the box also needed to be sufficient to sit two 30lb honey buckets one on top of the other with a rack to stand them on and room for the tube heater under the rack. In my case that’s about 500mm.
I added some handles because, well, they were there 😀
The box is lined with 50mm PIR insulation board, edges taped up with aluminium tape.
Even the lid had some glued to the underside using PVA.
I cut an internal floor that allowed me to fix the tube heater in place and made up a rack from bits of scrap pine shelving. Probably several different shelves by the looks of it. It’s hidden in this photo, but under the far end of the shelving and attached to it is a 100mm 12V PC fan. One of the older ones that just has a positive and negative supply, not the newer types that have speed control on a third wire.
Also in that photo you can see the wiring for an STC-1000 solid state relay set into the box from the outside so I can control the target temperature. Also on the outside is a 240V socket into which I plugged a 12V wall-wart to power the fan. I could have bought a 240V fan and avoided using the wall-wart and socket, but I had all the parts in the workshop so it cost me nothing to re-use them.
Testing time!
And in case the display is a little difficult to read…
After a few hours of running…
