Finally started a Hardie Backer Smoker

Discussion in 'Smoke Houses' started by wazoo, Feb 11, 2013.

  1. wazoo

    wazoo Fire Starter

    I have been planning on building a smoker for several months.  After a lot of review of this site and a couple of others it was time to stop planning and start building!  In the words of George Patton “A good plan violently executed now is better than a perfect plan executed next week.”   I want thank Gary (BabySmokologist) for putting up with my questions and Rancid CrabTree for great place to start.  The final product will be a insulated aluminum lined adjustable dual stack smoker for both hot an cold smoke.   

    The smoker particulars: Construction - Plywood T1-11 siding on a 2 x 4 frame insulated lined with Hardie backer board covered by .040"  5052 aluminum sheeting.  Smoke chamber is 24" x 20" x 4 ft high.  Burner area is 24" x 20" x 18" lined with ceramic tile with a Northern Tools burner.  Vents are 1 - 12" x 14" on the front and 2 - 3 1/2" circular on the sides.

    I have seen some comments over time about medium to tall smokers having a temperature gradient from top to bottom.  I know this is splitting hairs but every now and then the engineer in me shows up.  Gator Pit out Texas, (a commercial steel smoker builder that has amazing products) has a model called a Dual Stacker that has solved the temperature gradient issue.  I really liked the idea of having adjustable stacks for playing with the temperatures. So I incorporated this feature into my design.  I am anxious to get this completed and running so I can check out the performance to see if I can really manipulate the temperature in the box with dampers in each stack.

    I am well into the build and thought I would put my progress up so far to get thoughts and comments.

    The frame laid out with cross members for material joints.

    The smoker is starting to take shape.  The box is line and I am finishing up the insulated door.

    I decided to use .040" 5052 aluminum sheet thinking I can bent it at home with no problem.  Not so much.  Getting clean sharp bends with this material and a not having a commercial break was an interesting challenge.  Scoring the material is the obvious answer but let me say setting a circular saw to score .040" material .020" deep without cutting totally through was entertaining. I did get my settings right and I was really happy with the outcome.

    I wanted to be sure that the stack vents are well sealed so I used a good amount of high temp silicon and the clamped the walls against the pipe flange and the box.

    You can also see the lip over the ceramic tile in this picture.  This will keep everything cleaner and also keep the tile in place.  I did not cement the tile in so that it can handle the heat expansion and contraction.

    Overall I am pretty pleased with my progress so far.  I am anxious to get it completed so that I can fire it up and test it out.  I want to get some things smoked for this month's throw down.  Here is picture of my progress as of last night including the door.  Gary had warned me that it was going to be heavy.  He wasn't lying.

    I will have more pictures later in the week.
  2. Looks great so far! That's gonna be a nice smoker when it's done  [​IMG]
  3. Great looking smoker Wazoo!  I just got done building one that was inspired from Rancid Crabtree as well, check it out in the bottom of my signature.  I would highly recommend a needle valve for your propane line it is a great way to fine tune the smoker temp without having to open any doors.
  4. jdwintx

    jdwintx Newbie

    That build looks great, I'm going to be starting a similar build this weekend.  I did have a question though.  I was wondering if instead of using aluminium to line the inside of the smoker which seems to be fairly common, if it would be possible to line the entire inside with ceramic tile such as you have done for the firebox portion.   I have several cases of plain white ceramic tile left over from a tiling project and was wondering what folks thought about that vs. aluminum?
  5. Very impressive build. Don't forget to build a furniture dolly to move it.
  6. wazoo

    wazoo Fire Starter

    Thank you for the comments on the smoker.  Luckily I have a commercial furniture dolly or I would have had to build this outside in the rain.

    As far as lining a smoker completely with tile, I would be concerned with keeping it attached to the walls.  It is surprising how much movement you can get from expansion and contraction do to heating an cooling.  I expect my smoker will see temperatures from 30 degrees to at least 250 degrees and maybe even 325 degrees (or at least that is what I am shooting for on the high end).  That is a big swing.  I think a lot of furnaces and things that have refractory brick have it retained mechanically rather than being cemented to walls.  The tile in my fire box is all free to move while being held in place with aluminum channels.  It is an interesting concept though.

  7. Wazoo, have you managed to find your temps yet?  can you hit and hold 325?  anything you'd do differently with the design if you were doing it again?
  8. wazoo

    wazoo Fire Starter

    I have had the smoker up an running for a couple of months now.  I have been very happy with it.  See the thread on the finished project

    I have been able to have pretty good control over the temperature.  I have cold smoked with an AMTS with temperatures in the 60's and 70's.  If I use the smallest burner on the Northern tool burner turned down as low as I can safely maintain it, I can keep the temperature around 115 to 120.  With everything turned on and the vents closed down I can run up to 350or higher.  I have not tried to keep it that hot for any amount of time.  I just don't smoke or cook anything that needs that temperature.  I did a chicken that I smoked up around 290 then finished of at 325 for about 10 minutes but that has been the hottest I have used it.  The Northern Tool burner had a few things that I wish were a little better but I still think it is a great burner for the price.

    The one thing that I have found interesting is that the temperature is hotter in the lower portion of the smoke chamber rather than the top.  I think this is because it is closer to the heat source.  I am still experimenting with the dual stacks to completely figure out the temperature dynamics.  I have been able to get the temperature balanced when I had things on several shelfs.  So overall the stack and venting combination has done what I wanted.

    There were a couple of additions that I made after I had it running for a while with a shelf and a storage area.  Other than that I can't really say that there is anything that I would change with the exception of setting up the burner to run off of a pilot light set up.  I am not comfortable having the smoker running if I am planning on being away from the house for a long time.  I don't like the thought of the flame blowing out and propane going into the fire chamber.  The pilot light setup is something that I am going to add but I need about $100 + or - to install that.  So I am just being a little more cautious with the flame management until that is done.  

    Overall I am very happy with it and have been able to create some great smoke food.  I have it smoking almost every weekend.

    Please contact me if you have any questions.  I would be happy to share anything I can.

    fixer likes this.
  9. s2k9k

    s2k9k AMNPS Test Group

    Where did you find a pilot set-up for $100?
  10. wazoo

    wazoo Fire Starter

    It is not a pre-packaged unit for that price.  I wish it was.  That is an estimate of what I think the parts are going to cost me.  I have been looking at parts on line and I think that I can get everything that I need as parts for an Endless summer propane heater for about that price.  I have also been looking at trying to get the guts out of an old propane oven.  I will post something as soon as I have it together and working.
  11. s2k9k

    s2k9k AMNPS Test Group

    Thanks Wazoo! I've been looking and was thinking everything was going to be around $300.
    I'm thinking of scrapping the propane idea and go electric, think I can get off cheaper and will be able to use a PID.
    Let us know what you find because I still haven't made up my mind!
  12. jackal12

    jackal12 Fire Starter

    Replace the hardi with durock. hardi led to a fire for me, it has no fire rating. even behind the wall no way i would leave it in.
  13. wazoo

    wazoo Fire Starter

    Thank you for the suggestion.  I appreciate the concern.  I do not have any concerns with my hardie board because of the construction differences.  I use hardie board only as a backer but it is not exposed directly to heat anywhere in the smoker.  I have ceramic tile on the bottom and all sides of the fire box and the smoke chamber is completely lined on the sides, top, and door with 0.04 aluminum sheet. I even lined all of the vents and exhaust stacks so everything has either a ceramic tile or an aluminum covering. The majority of the hardie board also is not in direct much wood.  So there is limited opportunity for it to become hot enough on the backside to start wood smoldering.  I also did put the legs on my burner so it is up off the floor which it think makes a big difference.  I have run it up as high a 325 without a problem.

    I did read the post on your fire.  Definitely no fun!  I am guessing having the burner directly on the hardie board lead to the crack and that is when things got ugly.  Glad to hear that you are up and running again.
  14. wazoo

    wazoo Fire Starter

    I found a safety pilot light set up at Lowes for $60.  I am going to check it you this weekend.  It is a manual system that does not use a PID so you will still have to control your heat with a needle valve and venting but I think it can add a huge degree of safety to using a propane burner.  I will just attach it so the pilot light is running next to the burner and is the ignition source when I turn the burner on.  No pilot light no gas to the burner.  Hopefully it is that simple.   Here is the link. 

    Has anyone else used this or something like it?

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