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Maintaining temp in offset smoker

Discussion in 'General Discussion' started by nmaust, Nov 13, 2013.

  1. nmaust

    nmaust Meat Mopper

    I'm not sure if this topic or something similar is already posted, but I couldn't find it using Tapatalk, so I thought I would start a new thread.
    [​IMG]The cooking area on my new smoker is about 30" wide (the right half of the attached image), & I have a large round smoker box. It seems to hold heat really well, but during am 18 hour cook this past weekend I used an 18# bag of charcoal (started the fire with about half of it) & 30# of foot long pecan logs. That seems like a lot of fuel. It was in the low 50's outside. I watched the temp and kept it around 225 from about 11:30pm til 3:30am. I was probably adding a small log and a few coals every hour. I added another log and a few coals & went down for a 2 hour nap. When I woke up, it was down to 160. I threw 2 logs on, opened the damper on the SFB, & slept for another 2 hours after which it was 180. It seems like after the initial coals were burned it was hard to keep the temp consistent.

    Any basic fire building/temp maintaining advice would be greatly appreciated.
  2. Hello nmaust.  Here is my opinion for what it is worth.  Others may have different advice.  This is only my opinion.  Great looking smoker, but I believe the design is what is letting you down.  The idea of the two smokers in one is great but the smoker not in use is acting as a heat sink to the side being used.  When using the firebox you are probably having to have your damper open wider because the other side is drawing heat away from your charcoal burner side.  It is all made from one big tank.  The reverse will be true when you use the propane side.  It's a "rob Peter to pay Paul" scenerio but I think your only two options is to use more coals than usual or to also heat the other side with coals or propane while using your firebox.  Hope someone else has a better idea. Good luck.  Keep Smokin!

  3. gary s

    gary s SMF Hall of Fame Pitmaster OTBS Member

    Please post some pictures of the inside of the FB and CC  this will help

  4. gary s

    gary s SMF Hall of Fame Pitmaster OTBS Member

    I also noticed this was made by JJ pits, contact them and explain the problem you are having. And see what they say.  Post Pictures anyway

  5. nmaust

    nmaust Meat Mopper

    I talked to their owner the other day, and he gave me a few pointers since he uses the same pit at home. I'll post some pictures of the inside soon. I like the idea of heating the other side up.
  6. gary s

    gary s SMF Hall of Fame Pitmaster OTBS Member

    Did you open one or both stacks while you were smoking.

  7. Hello.  Thanks for having a look Gary.  I hope you have a better idea.  I just feel one is sapping heat from the other.  More heads working on the problem the better the solution.

  8. gary s

    gary s SMF Hall of Fame Pitmaster OTBS Member

    I looked on JJ's web site I didn't see the smoker you have in there pictures.  Wonder if this is a new or old design?  Is it a grill and a smoker? I saw the burner on the end and assumed that was what the propane bottle holder was for.

  9. nmaust

    nmaust Meat Mopper

    I asked the owner about it, & he said they've made this design for years but are in the process of updating the website. It's setup like a Chargriller Duo...The left side and burner are propane while the right side and SFB are for charcoal and wood. I didn't pay any attention to the stack on the left/propane side, because I didn't think that side would be a factor in maintaining the temperature. I had the smoker stack halfway open for most of the smoke. He said if I'm not going to monitor it for awhile I should close the stack 75%, open the damper on the SFB most of the way and add logs with only part of them in the coals do they burn slowly. He said he can typically go 10 hours on this unit with just a bag of charcoal & a few wood chunks. Should I try adding a full bag of charcoal to start the smoke, add wood for some smoke and then add fuel as needed? I just ordered a Maverick 733 to help monitor the temp and alert me if it drops.
  10. so ms smoker

    so ms smoker Master of the Pit Group Lead OTBS Member

      I would say to add a charcoal basket to any SFB.  Once burning, exhaust stack fully open, intake mostly closed. Give it a try.

  11. gary s

    gary s SMF Hall of Fame Pitmaster OTBS Member

    Pictures would be helpful, Is the cook chamber open all the way across both sides or are they two separate unites ? If it is open all the way I would close the stack on the right, open the stack on the left and control your temp using the damper on the firebox. I also assume that you have a charcoal/wood rack or basket that is at least 4" above the bottom of the FB. Also if you decide to post pictures include the FB door, inside the FB, CC with  both doors open, a picture of of the opening between FB and CC

  12. nmaust

    nmaust Meat Mopper

    I'm take done pictures tonight when I'm grilling steaks. There is a quarter inch thick piece of metal between the charcoal side and gas side.
  13. cliffcarter

    cliffcarter Master of the Pit Group Lead OTBS Member

    So your half bag of charcoal and 4 logs of pecan gave you temps of 225° for 4 hours at the start of your cook, is that correct?

    And you averaged 1 pound of charcoal and one log an hour for 18 hours?

    Were you using lump or briquettes? If you were using briquettes ash build up from them may explain the difficulty maintaining consistent temps

    Two things to consider-

    1. sleep and tending an offset do not often go well together and

    2. I think that if you had cleaned the ashes as best as you could from the SFB at 3:30 and added the other half bag of charcoal, using the same procedure you used to start your fire, you would have gotten a repeat of the first 4 hours.

    IMHO 18 pounds of charcoal and one log per hour, whatever size that maybe, sounds about right to me for an 18 hour cook, maybe even a bit light on the charcoal. If I used a combo of wood and lump charcoal in my CharGriller for an 18 hour cook I would probably use that much fuel or close to it.

  14. nmaust

    nmaust Meat Mopper

    I used bruises briquettes, & they definitely created more ash than I would prefer. I need to get a charcoal basket that makes it easier to clear ash away for sure.

    Here are pictures for those who wanted to see:

    Inside the SFB [​IMG]
    SFB door[​IMG]
    Cooking chamber[​IMG]
    Wall between the charcoal and gas chambers. [​IMG]
  15. gary s

    gary s SMF Hall of Fame Pitmaster OTBS Member

    Hard to tell from picture, but it looks like the plate dividing the charcoal and gas chambers does go all the way to the bottom, making two separate chambers. If this is the case I would open the smoke stack all the way, control your temp by the amount of charcoal, wood and damper in the FB door. I agree with Cliffcarter about keeping the ashes cleaned out underneath this does create air flow problems, for an i8 hour cook that doesn't really seem to excessive on fuel. Keeping the ashes cleaned out, stack open you may reduce your fuel consumption a little. Like he said hard to sleep and maintain cooking temps on an offset. I have a RF and cannot think about going to sleep.