I finally finished my RFB (rear fire box) for my GOSM (Great Outdoors Smokey Mountain) propane smoker. Awhile back I posted some pictures of a prototype I was working on and I have finished it. This all came about because I want to be able to use an AMNPS during hot smokes so I don't have to keep opening the door and adding wood. Wood chunks only last about 45 minutes in the chip pan so I am constantly opening the door and letting heat out so I thought the AMNPS would solve this problem but after much research I learned the AMNPS doesn't really work very good inside of propane smokers during hot smokes. I got a lot of great advice from "forluvofsmoke", "NWDave" and "TJohnson" and one of them (I forget now) added a CharGriller side fire box to their GOSM to use the AMNPS, so I thought "that must be the way to go". Well being I'm cheap and always like to find an inexpensive way out I started looking for alternatives to the $60 CG SFB. I read about using a mailbox and then thought of a metal toolbox because I like the way the top opened. I found one at my Dads house he didn't want so I went to work. I decided to mount it on the back because the side wasn't wide enough. I wanted to make it able to be taken off in case I didn't want to use it or needed to move the smoker, so I found some old drawer slides in my garage and mounted them on the bottom and also cut a hole in the back for the transfer pipe: I made a transfer pipe out of a piece of sheet metal and after cutting a hole in the toolbox mounted it to the back of the box and sealed it with some high temp RTV, I didn't get a picture but I also cut a hole in the end of the toolbox and used a piece of sheet metal as a damper: During my prototype I had a lot of smoke leakage so I sealed everything up real good on this one. I put high temp rope gasket around the edge of the lid of the toolbox: And also used it around the hole where the transfer pipe enters the back of the smoker: Now all I have to do is slide out the supports and guide the transfer pipe into the smoker and it is ready to go: And inside view: I smoked some ribs this weekend and used my chip pan inside the RFB and it worked great. I put 4 pieces of charcoal in the pan and lit them with a propane torch then set 2 chunks of hickory on top and shut the lid. It produced a real nice TBS out the top vent of the smoker for 2 hours, those same 2 chunks in the pan inside of the smoker would have only lasted about 45 minutes. When the TBS went away all I had to open was the RFB and stoke up the wood a bit and I added another chunk and it kept going. I played around to see and I was able to control the amount of smoke adjusting the damper on the side controlling how much fresh air was going into it. I was able to go the first 3 hours of my 3-2-1 ribs without ever opening the door to the smoker and still keep smoke going the whole time. I feel this was a success and I have less than $20 in it. I do not have an AMNPS yet but I am confident that it will work and that I will be able to get 8-10 hours of smoke without having to touch anything except maybe the damper. Now my dilemma, I hear Todd is working on something new, so do I go ahead and buy an AMNPS or wait and see what he is working on? Hmmmmmmm Thanks for looking!