I'm working on a cheese vat using a stainless steel utility sink. The one I've got is 18"x18"x12" and will take about 15 gallons (I haven't yet filled it to capacity). I heat the vat with rubber heating pads. Tonight I filled the vat with water and ran the autotune on my controller. It seems to work pretty well.
[img width= height= alt=utility sink vat showing controller.]https://sphotos-b.xx.fbcdn.net/hphotos-ash4/387526_303187653140015_1560596909_n.jpg[/img]
The brown line going into the water is a waterproof thermocouple. This image shows the vat with 4 gallons +1 quart of water. I will continue making 4 gallon batches even though I've got the larger capacity until I can get/make a bigger mold (or stackable molds) and a press that will accommodate more cheese.
I initially ordered a 6"x18" heating pad. It was not one of my finer reasoning moments. I thought, "oh, the vat is 18" so I can get an 18" pad for the bottom...". However, the bottom has legs in the way.
[img width= height= alt=large pad angled across the bottom]https://sphotos-b.xx.fbcdn.net/hphotos-ash3/541605_303198313138949_1309383111_n.jpg[/img]
Turns out that heat doesn't transfer very well through polymers.... After burning up that heating pad and making my house smell a little funny (I watched it the whole time, so it wasn't too dangerous--mostly disappointing), I figured I'd need something different.
Once I got over the disappointment, I ordered an assortment of pads (because the ones I really wanted had a 5 week lead time). I've got 2 5"x8"s, 1 3"x6" and 1 2"x10". Each are 10 watts/in^2 for a total of 1180 watts. Here's how they are arranged, all on the bottom:
[img width= height= alt=bottom of vat showing pad arrangement]https://sphotos-b.xx.fbcdn.net/hphotos-ash3/574995_303187656473348_1923952250_n.jpg[/img]
I have a few things that I'm concerned with. The first is that the pads run at about 90 F hotter than the water temp. I'm a little worried that the heat transfer into the milk will be too fast and I'll get some scalding going on. You can see the accumulation of bubbles in the water, which was not stirred at all during heating, in the next image. I'm hoping to be able to compensate for that by stirring when I actually make cheese. I'll report on that after I've tried. Another concern that I've got is the drain:
[img width= height= alt=picture of drain]https://sphotos-b.xx.fbcdn.net/hphotos-ash4/312461_303187649806682_1232721355_n.jpg[/img]
I'm sure this is a potential contamination site. I can remove and clean the drain and gasket every time I make cheese, but I'm lazy and would prefer it if there were a less labor intensive way to sanitize it.
What are your thoughts and reactions? There's more story/details to tell, but I thought I'd put out this much and see if anyone is interested in knowing more.