New OK Joe Questions

Discussion in 'Wood Smokers' started by smokey kevin, May 10, 2013.

  1. smokey kevin

    smokey kevin Newbie


    New to smoking and just picked up my first BBQ - An Oklahoma Joe Longhorn.

    From all the good avice on this forum, I've already made a few mods.

    Got the right angle tubing from Lowes to extend the smoke stack down further:

    I built a diffuser plate for better heat distribution across the cooking chamber from the fire box. 18x24 16 gauge steel with bends at 2" and 9.5". Holes along the way small to big.

    Lastly I built a charcoal box from expanded metal:

    What has me concerned now is the drastic temp difference from the top of the smoker to the cooking grate. The installed thermo towards the top reads as much as 100 degrees difference from what I'm seeing at the cooking grate. I'm measuring the cooking grate with an electric thermo and have verified the top with the same just to make sure the cheap thermo included with the smoker isn't way off. As an example, if the cooking grate is at 250 (kinda where I want it), the top of the smoker reads about 350-400. I would expect the heat to rise, and the top to be hotter, but this seems like to much of a difference and I was hoping the above mods would have evened things out more. The cooking zone is basically still a cold spot even with the mods. Any thoughts or advice?

    I noticed the cooking chamber door is leaking quite a bit and am going to go to work on fixing that now. Could the leaks on the top part of the door be pulling the heat up and causing what I'm seeing?

    Also, the diffuser plate doesn't sit exactly flush with the fire box wall. Has a couple spots with very small cracks. Could that much heat be getting out and up there? That would be easy to seal.

    Wanting to get everything nice and even so I can start cranking out some delicious meats.

    Thanks in advance!

  2. buttburner

    buttburner Meat Mopper

    I have the same smoker.

    First, make sure that thermo is reading correctly. Put it in a pan of boiling water and make sure its around 212f

    My thermo never ever reads higher than my grate. Reads maybe 50f lower.. I sealed off the cooking chamber with some gasket material but that doesnt make much difference as far as temps go, but mine did not leak much to begin with I dont pay much attention to that therno anyway, I am not cooking up there where it is located

    I have a deflector and tuning plates that are somewhat different than yours but not that much. I dont have any holes in the angled area by the firebox, mine is solid. Maybe foil that up and see if it helps, maybe thats why you are getting hot at the top of the chamber

    There may be some differences in the heat zones but not enough to concern me. I like having a hot spot for crisping chicken etc

    I just stick my grate thermo midpoint of where the meat is and adjust my fire to what I want the temp to be at the meat. 

    Another thing that helps is put a water pan at the firebox side of the cooking chamber, helps even out the heat

    And I put a layer of folded up HD foil between my diffuser plate and the firebox wall to seal that up

    This is how mine was setup at first, i put the foil along the top edge of the plate, then I also removed the plate on the left and spread them out some

    Last edited: May 10, 2013
  3. smokey kevin

    smokey kevin Newbie

    Thanks Buttburner.

    I double checked the hot zone with the electric thermo and sure enough it's much hotter up there. I a m going to try the foil and patching up the holes on the angle. I'm also starting to get concerned that I put too many holes in the plate.

    At any rate I'm able to keep a good temp at the grate.

    Thanks for the help.
  4. buttburner

    buttburner Meat Mopper

    the main point is you have good temps at the grate. You cam also try blocking off holes in the plate with foil if you think that will help.

    Thats why I went with tuning plates over a plate with holes drilled in it
  5. smokey kevin

    smokey kevin Newbie

    Thanks for all the advice man.

    I should have read your first reply closer. I was working off the assumption (a bad one) that the brand new electric thermo had to be readonably accurate.

    Last night after controlling a practice burn for several hours, and still with the heat difference I decided to put both thermos in boiling water side by side.

    Low and behold the electic thermo was about 50 degrees low and the cheap thermo included with the smoker was roughly 20 degrees high.

    This means they will read about 70 degrees off from one another AT THE SALE TEMP. I feel dumb.

    Thanks again for the time and help.

  6. smokey kevin

    smokey kevin Newbie

  7. oldschoolbbq

    oldschoolbbq Smoking Guru OTBS Member

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