Controlling heat issues on smoker.

[h2oman]

 

[h2oman]

This is my smoker that I built and I can't control the heat. I have done 6 test burns and cannot keep it at the 225 degrees mark. Even if I shut down the damper, it will continue to rise. I started with a 4" flue and my damper is 4"x 9", they are on opposite sides to allow for good transfer of heat and smoke. I thought the flue was not dissipating the heat enough, so I went with a 6" flue but it helped just a little. I have looked for leaks by using a smoldering piece of paper going around the doors and the box but all seems fine. The box is 45"x 30"x 22" (inside dimension) double walled 5/8 plywood with 1"x 3" frame laid flat so my walls are 2" thick. I had extra plywood and filled all the spaces between the one by threes creating a solid wall and roof. It is wrapped with sheet metal, sealed with food grade heat resistant silicone (red stuff), high temp gaskets on box and doors. My firebox as you can see is the minion method. It is 20"x 14" x 7" high. After my first burn I realized that the dividers did not extend far enough to the other side allowing for the fuel source to ignite to soon on adjoining sections creating more heat (I think, sounded good). So I extended them a few inches. I welded 1x1 square tubing onto the bottom of the fb so the ash could fall through and keep the burn section clear. It seems so simple, light a few briquettes, add to the loaded firebox, open damper halfway, fully open flue and as the heat starts to rise start closing the damper until you hit your temp. right? I leave the flue fully open. I am retired and living the past 6 years in Mexico on the Sea of Cortez and the one thing that I miss is good BBQ. Here they just put meat on an open grate and fire up the mesquite. No pulled pork, brisket, sausages, the basics. So in between my fishing, I started this project thinking it would be a piece of cake and I would be enjoying good smoked BBQ. Went up to the states over Thanksgiving and bought back all the Lump, Briquettes, Apple, Cherry, Pecan, Alder, Hickory I would need before my next trip North. Any help/ideas would be appreciated. South of the Border smoker.

 

[radio]

Good looking smoker, and well insulated!
Looking at the pics, the only things I can think of is too many briquettes in the fire box, as in layered too deep, or too many are igniting at once. With that much insulation, you could almost heat that beast to 225° with a candle!:D
Try putting them in only one or two deep and be sure to start them only on one end of the maze. Leave the stack open and adjust air with the dampers. They likely will only need to barely cracked to provide enough air. If sill too hot, modify the firebox maze so it is narrower and less briquettes are burning at one time.
Get a good remote probe thermometer so you don't have to open the door to check temp

Good luck, and keep us posted

 

[h2oman]

Good looking smoker, and well insulated!
Looking at the pics, the only things I can think of is too many briquettes in the fire box, as in layered too deep, or too many are igniting at once. With that much insulation, you could almost heat that beast to 225° with a candle!:D
Try putting them in only one or two deep and be sure to start them only on one end of the maze. Leave the stack open and adjust air with the dampers. They likely will only need to barely cracked to provide enough air. If sill too hot, modify the firebox maze so it is narrower and less briquettes are burning at one time.
Get a good remote probe thermometer so you don't have to open the door to check temp

Good luck, and keep us posted

Thanks Radio for the reply. I only have the one damper on the left side as shown in the pic. The flue is on the right side. My thinking was the smoke would travel across the interior of the box making contact with the meats. If that makes any sense. Do I need another damper? if so where? I get the firebox dilemma. I thought no matter the amount of briquettes it would burn slow because of less air. Plus I wanted to make sure that I had enough fuel for a "Boston Butt" or a brisket. As it was, I was getting 8 hrs using half the fb in the test burns. I will do a small snake around the box and start it with just a couple of briquettes and see if that is the key. I need to make sure I get enough of an air transfer so the smoke doesn't linger in the box. A chunk or two of fruit wood for smoke will add to the heat. I will keep you posted. By the way I picked up a ThermoPro TP 20 last week when I was in the states to see the family. My door thermo and the inside oven thermo are within 1 degree, so I don't have to open the door. Again thanks, you got me thinking straight again. All along I thought I had an air leak. So easy to over think this....

 

[daveomak]

Try lighting 4-5 briquettes and using those as a fire starter.. set them at the end of the "snake" and only have 1 air inlet open about 1"... as the temp rises, shut down the air inlet to 1/2".. maybe 1/4"... you will figure it out sooner or later.. You may need to close down the exhaust partially, if you can't control the temp... even the smallest air leak will give you major headaches when trying to control temp....

 

[maineac]

I agree with Dave. You have fuel and oxygen and the precision with which you control each will allow you to control the temperature. I also think the 4” flue should work for you.