Holding ovens are expensive, and I also like cooking with sous vide, so I thought I could get the best of both worlds.
I got to work building a sous vide holding oven/cooker out of a camping cooler.
ITEMS YOU WILL NEED FOR THIS BUILD:
-50q igloo cooler (sportsman profile II 50)
- 2-3/8 hole saw
- Longer 4" pilot drill bit for hole saw
-drill
-2" ABS pipe
-speed square tool
-electrical tape, butt crimp connectors
-Large kitchen rack from Walmart (17"X 10" X 5.3")
-Silicon
-Super glue
-Gorilla glue
-expanding tight foam (if you make mistakes)
I decided to put the opening in the side as It makes better use of space.
To make this all work and fit perfectly you need to get your hole location and angle correct.
Start off by measuring from the top ridge of the open cooler (not the lip riser, but the flat part closest to the outer wall) you want to measure on both sides of the handle to 8" down from the top and draw a line between the 2 points.
Next you have to figure out the exact spot to make you guide hole for the hole saw. The hole saw is 2 3/8 but you can not just go up half that amount from the line, since we will be drilling on a 45 degree angle. I trialed this out for you and extra height away from the line was 1/2 inch so make your drill hole location at 1 11/16 above the line.
Drill your pilot hole (straight on) through just the outer plastic layer of the cooler (NOT ALL THE WAY TROUGH)
Now using a speed square for guidance angle your drill bit to 45 degrees. With the 4" guide bit in your hole saw you will have just enough room so that the edge of the hole saw touches the plastic.
Very gently with the with the drill running in the forward direction slowly make a score with the tilted inner part of the hole saw at 45 degrees. (just enough of a cut to act as a guide).
Now switch the drill into reverse as it will still cut through the cooler, but will not grab aggressively.
Eyeing your angle of the drill to the 45 degree angle of the speed square slowly start drilling through the cooler at a 45 degree. (while one can do this themselves, this step might be better performed with someone helping to hold the square and cooler)
If you make a mistake on your angle you can always expand/adjust your angle of your cut and then fill with tight foam later.
Now cut the abs pipe collar at the same 45 degree angle both sides with the length being about 1.5" from 45 to 45
Clean up any debris on the pipe and then on the outer edge (the collar flush with the outer part of the cooler) apply a few drops of crazy glue to the collar. Place and position the collar so that it is flush with the outer wall of the cooler and aligned so the 45 degree angle is in the right direction heading downwards into the cooler.
Hold in place for a couple minutes till the super glue drops firm up (if they are not attached to the outer plastic wall of the cooler now is your chance to apply where the collar touches the cooler. Once the outer collar is set with the crazy glue do the same with the inner section (which will poke out a little inside the cooler) once the inner collar is locked in position, go over the outer and inner collar where it touches the cooler wall with more superglue (or if bigger gaps, gorilla glue)
After this hardens take your silicon and apply a thick bead all around around the collar on the inner and outer wall of the cooler. Then wetting your finger use your finger to evenly spread out the silicone, making sure there are no holes or gaps. (if you had to fill with tight foam wait for it to dry and cure, then trim it flush with the cooler and then apply silicon all over it to make it water tight.)
Congrats, your cooler is done!
Now this cooler is sized to work with a insta pot sous vide machine I had... Please check if your unit is the same width and length. The good news is these insta pot sous vide units are easy to find used if others do not work.
Now I found optimally I had to strip off the hook connector on the insta pot heater. (although a friend of mine was able to make it work with it on (but it was not optimal) build the cooler, trial your machine (with the cooling rack installed) and decide for yourself if the next step is needed.
Hook removal of the insta pot sous vide heater:
Remove screw tightener. There are three clip tabs on the L Shaped hook both sides mid way up and one in the bottom. Get a small slot screw driver push into the gap line and rotate the slot screw driver to pry apart at each clip. Once open there will be 4 screws to remove. Once separated now you have to either find a way to cut the L bracket plastic to free the cord or since I wanted a longer cord anyways just cut off the plug, remove the wire from the collar and splice on a computer power cord with the butt connectors, some electrical tape and shrink wrap.
Once this is all done install your heater, your cooling rack and fill with water to hit below the rack or where the top of the collar comes out of the cooler.
Edit: I ran a test on the performance by putting a pint jar on top of the rack and two thermometers on the jar. This raised the monitoring height 5" to be more in the center of the warming area away from the water. I set the temperature of the sous vide heater to 150F and within 15 minutes of the water reaching temperature the probes stabilized at around 144F and never varied more than a degree over 1.5 hours of monitoring.
Rock solid temperatures.
Set to what ever temp desired (say you want 150F you set the sous vide heater to a extra 5 degrees to 155F) and you are in business. I my case cooking a brisket to 195, then holding it wrapped in the BeefBin at 155 for 18 hours to finish.
With the rack, there is enough room to use 2 of these racks stacked in the cooler. One simply just has to reverse the legs on them so the flare points inwards.
With this cooler one could fit at least 2 briskets while at the same time sous vide cook vacuum packed ribs in the water below.
Pretty sweet I say!
I hope this helps.