I'm a new member, but have read through these forums a lot in preparation for my build. Thought I'd join up here & share the build. Noticed just a few posts back someone asking about food warmer conversions, and I can say they work remarkably well!
I found a discarded Traulsen warmer at a school district auction and got it for less than $100.
Built out a control panel for the top (which was damaged anyway).
I chose not to use the 220V elements already in the device, but am now considering re-wiring it for 220 to use those elements. They are seriously huge and high quality.
But, this simple control activates plugs behind the wall. Each plug operates it's element. The PID and Convection plug also operate additional fans which cool those two items. The fan motor is external, but gets hot without the fan. The PID gets hot because it's carrying a lot of current.
I used a modified add-on chip burner I had seen people talk about on numerous forums. (http://www.allchinas.com/burner/) Got it off Ebay. Thought about building one, but this was is exceptionally well built, and stainless, which fit everything else.
This was made to be a full burner for add-on to existing charcoal boxes. But, I modified it by adding a telescoped 4" over 3" SS pipe. The inner pipe carries the heat and the outer insulates/shields it from melting the insulation on the box (which should be rated for some 375 or so). I also put a layer of heat grout about two inches around the pipe where it penetrated the box. So far (about 20 smokes down) so good.
This firebox is perfect for this situation. I put two different ranges of rheostats on it. A lower speed range for burning smaller chips and chunks and a faster fan for burning logs. Yes- that sucker will burn a three inch log like a cigar, which is great for smoking sausage.
A 14" log will burn 6 hours plus. A hopper full of such logs chopped into 2 to 3 inch chunks goes 5-6 hours - and generates quite a bit of heat. In fact, I have to use the low range fan - at a low setting - or I'll blow my temp range out. After a bit of playing with it, it's fairly easy to find the right range for the wood used so the assist takes over control of actual temps.
For that, I'm using an Auber 1800 watt digital controller. It has 6 stages of programming, using box and/or internal food probe temps. Does a FANTASTIC job. Once equalized, it literally never roams from 225 - unless I do something to the firebox to throw it off (like let it burn out, or stoke it).
Also added a convection fan to keep temps even- since it's such a big box (some 25 cubic feet of cooking area). The most I've loaded it with is 40-50 lbs of link sausage, but I could have probably doubled that - assuming my hanging system could support the weight.
This was one of those projects that never happen.... Everything worked - first time - and just as I had imagined. Of course, I'll still tweak it, but couldn't be more happy with the results. I've been smoking something just about every weekend - and during the week too. The great thing about the Auber is, I can put something on - go to work - and it will do its job without me. Since I can put 6-8 hours of smoke on something in that time, it's got all the meat will take even if my fire goes out. And, the element I used can keep up without the firebox. Thus, I can set it & leave.
My last stage of any program is a 170 hold for 10 hours. However long I'm out, my food is sitting in a holder waiting for me when I get home.
I also did a YouTube video of it in action here.
Those of you considering a build - I can't think of anything - short of taking vacation and doing it all from scratch - that would have served this purpose better than this food warmer.