Oklahoma Joe Tempt Control Thoughts

Discussion in 'Charcoal Smokers' started by martin, Apr 5, 2015.

  1. martin

    martin Fire Starter

    Oi all! I have been smoking for a while so I am not totally a noob. Recently I invested in an Oklahoma Joe Longhorn. I completed my mods and did a seasoning run and then the next day a short smoke of some jalapenos just so I could start drinking beer earlier. So here is what I have and what I have done. My question(s) are about how to equalize the heat and about the difference between briquettes and lump. So here we go.

    Here is what I have

    Oklahoma Joe Longhorn with the following modifications:

    Sealed the joints and smoker door.

    Put latches on both sides of smoker door to tighten it down a bit.

    Lowered exhaust to grate level.

    Convection plate that runs just short of half way down the smoker, right to left. It does have the holes in it.

    Charcoal basket.

    Day 1 seasoning:

    I prepped the smoker for seasoning. Used standard briquettes with the Minion method. Fired it up and ran through the dry run. I watched my temps with internal Maverick probes that I made sure were accurate that day. I found that at low temps the heat variation from right to left was just a few degrees. At 300 degrees I hit the biggest variation with 25 degrees difference between the left and right side. Obviously the right side (firebox side) was hottest. I thought this was okay. I used a few chunks of wood to get a good smell going. The smoke color looked good. I finished the seasoning.

    After the Okie Joe cooled I cleaned out the firebox. I checked out the inside to see if I could mitigate the heat variation from right to left. Where the convection plate rests on the right side of the smoker I did note the bolt heads from the bolts that mount the firebox to the smoker stuck out 3/8 inch or so allowing for a 3/8 gap between the convection plate and the side wall. I used some foil and sealed this gap up creating no dead space between the side wall and the convection plate.

    Day 2 Smoke:

    After I used the foil I started prepping for a quick smoke. I used the same calibrated probes inside the smoker, one on the left and one on the right. I also used the Minion method again. This time I used briquettes to start it off but lump in the actual charcoal basket for the smoke. I fired the smoker up and was able to get up to temp easy and fast. What I found out now was that the left side of the smoker ran between 25-50 degrees cooler. 25 at lower temps and 50 at higher temps, (after I pulled the jalapenos I cranked the smoker up to 300 to watch it burn a bit). I also noted that the color of the smoke was darker than what I wanted. I used a handful of wood chunks in this smoke. Because the time for this smoke was so short I did not have to add more lump. One basket full ran for hours and was actually good to find out about.

    So here are my questions and please supply your thoughts:

    1. How can sealing the gap between the convection pate and side wall fail to equalize the heat? Did this add to the temp problem?

    2. Does lump burn that much hotter than briquettes?

    3. The dark color smoke I am sure comes from the lump. Is this good, bad, or whatever?

    4. Would extending the convection plate help to equalize the heat (I am leaning towards this for the next step)?

    Thanks for your input all!

  2. valleypoboy

    valleypoboy Smoke Blower

    I'd love to say stick around and someone can answer your all questions, but I think only YOU will be able to answer some of your questions. I've got the Highland and my new heat diffuser resulted in a pretty massive 100* difference between fire box side and exhaust side so I'll be re-desiging mine, though reading your results, maybe I should have just left a small gap?

    I suppose the problem is an air current one and without some advanced engineering, it's just trial and error for us DIY'ers. I'd guess the gap you had in your first experiment caused some of the heat to go straight up, but most of it was drawn down below the diffuser, when the 2 currents meet back up in the middle of your CC they would create turbulance and help to disperse the heat through the CC.
    Last edited: Apr 13, 2015
  3. The way to verify whether your lump is the culprit in the issue of the nature of the smoke is to go back to briquet charcoal and see.

    Q: What brand lump? What brand charcoal?

    Q: What type of wood chunk? Did it still have the bark? Did you load it cold or warmed up?

    Q: Can you post up pics of your deflector/diffuser setup?

    Note that rapid temperature increases in the firebox (i.e. adding readily combustible fuel) are going to translate into an initial heat spike on the inlet side of the CC, and then will moderate and level out with the vent side 20-45 minutes later.
    Last edited: Apr 15, 2015
  4. martin

    martin Fire Starter

    Thanks for the responses! The photos attached are of the Okie-Joe. The inside photos are left to right. You can see the convection plate and where it sits next to the common wall between the inside of the smoker and the fire box. The foil is what I did to plug the gab between the convection plate and side wall of the smoker.

    I was using Kingsford briquettes on that run and Royal Oak lump. The wood was cold when I put it in and did not have the bark.

    Valleypoboy, I agree with you about the air currents. I think when I filled the gap with foil it caused that area to get extremely hot (the side wall of the smoker, the convection plate, and foil). That raised and retained the heat in the material itself without allowing it to bleed off.

    So here is my recommendation to myself:

    1. Remove the foil.

    2. Let the wood warm up before adding to the mix.

    3. Monitor the temps again during a smoke.

    4. Grab a six pack or two, pop the first brew and quit worrying about it. [​IMG]

    Anymore suggestions or help I will gladly take. You'all have a good one. Blue smoke baby!

  5. I also believe that those deflector designs that have a short, steep, angled face (like yours, Horizon's, etc) are somewhat stifling proper draft flow. I've posted up pics of my deflector plate in other threads, but I'll post it up here again for the sake of this conversation. It is made of dual-layer aluminum and therefore minimizes the RADIANT heat issue of that plate steel. Here is the product. I got it from the baking section at Target for $12/set:

    Here is the modified deflector installed. Notice the shallow angle:

    I usually put an aluminum drip pan in (resting on the lower grate, generally up against or close to the deflector's lower edge) and get GREAT draft with this setup. Here's a diagram of what I mean:

    When settled, I get chamber temps within 5-8F of each end. Make sure you always have your exhaust vent WIDE OPEN.

    Are you monitoring chamber temps from those two thermos mounted toward the top of the lid?
    Last edited: Apr 16, 2015
  6. martin

    martin Fire Starter

    Your resolution to the convection plate Remmy700P looks excellent and the price is right. I am going to add the drip pan next time. I did not on the original runs in that they were to season the smoker and I did not have any food in it. I probably should have in that it does affect the overall operation. Thank you!

    By the way I operated the 700P platform for a few years. Shot with some good people.

    Thanks for your thoughts

    remmy700p likes this.
  7. valleypoboy

    valleypoboy Smoke Blower

    What are the dimensions of your plate? I could probably straighten out my steel plate and see how it performs with a shallower angle, but it's only 12" long measuring from FB toward center of CC.
  8. It's 14" long and 16" wide. Works great at turning that firebox-side heat blast into uniform CONVECTIVE heat in my TMLE, but still allows you to choose a hotter and colder side to smoke/roast on.

    Try straightening it out entirely and suspending one end just above the top of the firebox inlet. I use flexible bansai tree wire to hang it from the end of the grate; it simply rests on the lower grate. Closeups (moved away from the end for ease of picture-taking):

  9. valleypoboy

    valleypoboy Smoke Blower

    Definitely have to do the wire thing. I straightened out the plate then tried to rest it on the bolts above the hole. It stayed for a time, but fell twice before I even started cooking so I gave up and left it sitting where it fell, a couple inches below the hole.
    I was getting between a 20 and 50* temp difference between left and right with it this way. I did a short smoke of a tri-tip and some corn. I checked the temp of the tri-tip at about 1:15 of cooking and it was already 130*. Moved it over to the FB for about 7 minutes per side, then brought in and foil wrapped.
    Came out great:
  10. martin

    martin Fire Starter

    O-man, I have been out of town working. Just got home, popped a brew and started catching up. Now I see your post with some nice looking grub. Damn and thank you!

  11. martin

    martin Fire Starter

    Well I removed the foil I placed around the convection plate and smoked a yard bird two days ago for a test run. I can handle the temp variation between right and left. Man was it a good run and the results were awesome. This Oklahoma Joe is by far enjoyable! Today is a small butt and a pastrami. No sushi tomorrow for me! Meat baby! Going to add some stuffed japs now for a late lunch. Smoke on bhoyos!


  12. I have experienced the same issue when I stop up the gap between the diffuser plate and the right side wall.  Heat goes way up on the right side.  I am going to try and bolt the plate to the wall,  Perhaps eliminating the gap by bolting the plate will make for an easier flow of air.???
  13. wichita chief

    wichita chief Fire Starter

    I made a filler plate to tie the heat management plate to the fire box wall which forces all heat to enter under the plate. I bolted it to the plate and to the firebox wall using the existing bolt locations on the firebox. 

    My plate is thick so it acts like a big heat sink to even out temp swings a small amount.

    It is for a Yoder Wichita but it fits my Okie Joe's Longhorn perfectly.
  14. I don't have a pic yet, but I actually bolted the diffuser plate up against the fb wall without driling new holes.  I got some oversized washers and used the existing bolts which pull the plate up pretty snugly.  I still was getting a huge difference, upwards of 40 degrees right to left.  However, I took the left plate and moved it to the right, covering the largest holes on the right plate and leaving a much bigger gap on the left side where the left diffuser was covering.  My temps evened out almost immediately.  I'm still only able to get the temp in side the cook chamber up to about 270, which is much lower than before I installed the diffuser plates.  However, I am only using RO Lump so Im sure I could get it even hotter with some wood splits.  I'm going to run another test and see if things hold true.  If so, I believe it is best to bolt the plate to the fb wall.
  15. wichita chief

    wichita chief Fire Starter

    Here's the view from the F/B side doing like what TCS1  mentioned. Using the bolts already there. I made the block off plate go into the F/B side to help close off the hole more vs. just keeping it in the cooking chamber.

  17. I am completely good now with these mods.  I am able to get well over 300 degrees in my CC.  One thing I noticed that is very important:  When I get in a hurry, I sometimes get my food in the CC before temp gets up to 300.  I'll throw it in at 240 or so then just level it off from there.  This saves time instead of backing off from 300 and getting down to 220-240.  I always have a problem with temp control if I go the shortcut and throw the food in around 240.  I am constantly fight trying to get the temp back up and even throughout.  If I am patient and back down from 300 to the right cooking temp, my cook is much more consistent throughout.  This is probably the most important thing I have learned with this smoker.

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