Just finished sucessfully drilling a hole in the side of my fridge for a heat belt and Elitech STC 1000 sensor!
I was going to use the cornflower and rubbing alcohol (or methylated spirits) trick to locate potential gas lines but I noticed when I turned the fridge on that day the side got unusually warm trying to heat the fridge up in the garage that day, presumably because it was 30c+ and it was working hard.....
I pressed my hand against the warm fridge side, each time I found a warm part I put a black dot using a non permanent marker. I did this all over the fridge side, then looked at the resulting chaos and went off for a coffee.
When I went back I now saw that the dots clearly marked out a gas line (I 'joined up the dots' with the pen so you can see in the picture below)
Having decided were to drill the hole, I heated up a pallette knife at the end on using the gas stove (a blow lamp would be better....) and carefully pressed it into the plastic side wall of the fridge. I went in just as far the thickness of the plastic, you can tell when it's enough as the resistance to the knife lessens.
I did this fout times to make a square hole and pulled off the surface plastic to reveal the inner foam of the fridge wall.
Having done this I took out the foam from behind the hole (carefully) with a screwdriver - when I hit the inside fridge wall I knew I was home and dry. All that was left to do was dill the hole. This went OK but I had to use the drill bit to elongate the hole to allow for the thickness of the heating belt, resulting in a jagged hole that needed cleaning up.
All I need to do now is fill the hole with expanding foam or plug it with a 35mm bit of thick polystyrene. We'll see, I don't think I can bring myself to buy a can of foam for a 35mm hole!
Now I've got a temperature controlled fermenting fridge I'm definiley looking forward to making more drinkable brews! :chug: