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    modify smoker/pit?

    see attached pics. this is an old pit/smoker that has been in the family a long time. I use it some but have a little trouble getting and holding temp (220-250). I am thinking of re-working it a little to improve it but not sure what all to do. any suggestions from the crappy cell phone pics? thanks
    Attached Files

    #2
    Difficult to tell but if I were going to do any work I would add a vertical smoker to the end pit opposite of the fire box. from the pics the pit appears to be in good shape so maybe sand blast and a new coat of paint?

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      #3
      Check out this forum http://www.texasbbqforum.com/
      There are a lot of great pit builders on there and they can give you some good info. It looks like your fire box is a little too small for your chamber size. There's actually a mathmatical formula for dimensions of firebox to chamber size to size of your smoke stack to properly create the airflow needed to maintain temps. Good luck.

      As for any welding work needed, if you can't do it yourself, you might want to check with your local FFA. A lot of those kids are looking for welding projects for class.

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        #4
        I agree, I think the fire box size is a little small. also, I am not sure about how the heat transfers from fire box into cook chamber. as of now there is a plate in between the two so the heat goes up, over, and down I guess.

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          #5
          I would start by making the stack taller, and possibly bigger material.

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            #6
            most people build the firebox 1/3 of the smoker area size.

            by the looks of the pictures the fire box is under sized, also taller stack will help draw the air = hotter temp

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              #7
              I also think the firebox and exhaust are too small. Make that stack longer and it will draw more air into the firebox, making the fire burn hotter. Another thing, and it may already be this way, hard to tell, but make sure your fire isn't sitting on the bottom of the firebox, it needs air to come in underneath it to burn as cleanly as possible. It's also hard to tell where that stack ties into the smoker. If it's right at the top, your smoke (and heat) is just jumping up over that diffuser plate, going down to the other end an going out the stack. Lower it down and that will force the smoke and heat to remain in the smoker until it banks down low enough to go out. This will also set up a convection current as the fresh smoke coming out of the firebox will be hotter than the smoke that's been in the smoker for a little while. The hotter smoke rises to the top of the chamber, forcing the cooler smoke down, it will create a minor vortex around your meat if the smoker seals up halfway decent. Last, it looks as if the bottom of the firebox is on the same level as the bottom of the cooking chamber. If you could drop that box down some, it would help with the heat moving into the box since heat rises. If I were going to cut the box off and move it down, I would increase the size of the box while i'm at it. Another option would be to cut the bottom off the cooking chamber and weld in new bottom plate higher up. This will serve the same purpose as dropping the firebox, but also reduce the internal volume of the main chamber, thereby decreasing the size of fire you need to keep that volume up to temp. In essence, you need to figure the volume of the main cooking area, divide by three and make the firebox volume 1/3 the volume of the cooking chamber. You can accomplish that by either making the firebox bigger, or the cooking chamber smaller.

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                #8
                Ttt

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                  #9
                  thanks for all replies. thanks txfieguy2003....great reply. Also, the golf cart that I bought from you is working great. thanks so much.

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                    #10
                    Glad you are happy with it! I turned that money around, added a little more and bought a 4-Wheeler. That cart just didn't cut it on my lease, and upgrades were going to cost way too much for my budget. It was a pleasure ding business with you.

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                      #11
                      Firebox appeared to extend into the pit some so it may be big enough.smoke stack is probably most of your issue.it needs to start below the cooking racks and be taller to create a draw.possibly bigger in diameter also

                      Comment


                        #12
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                        The smoker looks like it is 36'' long with a firebox 12'' Long 24''Hx24''W. I'm just guessing on that by kinda going off the 1 1/2'' #9 expanded metal.



                        so if the above is right you need to add 6'' to the firebox length to have the firebox right.


                        Now for the smoke stack:


                        smoke stack should be 5% of the firebox volume.


                        hope this helps,

                        your firebox as is comes out to 6,912 cubic in.

                        if you use a 3'' stack it should be 48.92''

                        if you use a 4'' stack it should be 27.52''

                        so you need to add a longer stack



                        if you do add the 6'' to the firebox length

                        and use a 3'' pipe for the stack it will need to be 73.38''

                        and a 4'' pipe for the stack will need to be 41.27''

                        Comment


                          #13
                          Rack'emJay, if your numbers are correct, his firebox would be the correct size as is from my understanding and experience. The firebox needs to be 1/3 the volume of the cooking chamber, not the whole pit. I really think if he cuts about 12" (again, assuming your dimensions are correct) off the bottom of the cooking chamber, and welds a new bottom on (or reuses the existing plate as the new bottom plate), he'll be in good shape.

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                            #14
                            I'd say he just needs a taller bigger smoke stack...oh I already did

                            Comment


                              #15
                              Originally posted by txfireguy2003 View Post
                              Rack'emJay, if your numbers are correct, his firebox would be the correct size as is from my understanding and experience. The firebox needs to be 1/3 the volume of the cooking chamber


                              I know the 1/3 thing I even wrote it in the 6th post.

                              good catch there TFG


                              these 16hr shifts are catching up with me, I'm not thinking real clear today.
                              Last edited by Rack'em Jay; 05-04-2013, 02:16 AM.

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