Signal Box Build

Discussion in 'Smoker Builds' started by robbs, Nov 12, 2012.

  1. I am in the process of building a smoker out of an aluminum traffic signal box and i would like to insulate it. I have read about using Hardie board as an insulator but I'm not sure how to install it. Is there an adhesive that is safe to use?
  2. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Robb, evening and welcome to the forum... The signal box is a good idea and a great start to a smoke chamber...  

    I would stay away from Hardie board...   It has too much thermal mass.... too long to heat and not that good as an insulator...

    How big is the box ??? Is it big enough you need insulation ??  Dave
  3. Thanks Dave, the dimensions of the box are 40"w x 56"h x 26"d (33.7cu ft). I plan on doing both hot & cold smoking and my thoughts are to use a pipe burner for the heat source and building a high nozzle (Venturi type) smoke generator to mounted to the outside of the box for smoking. I haven't gotten around to the internal layout of the shelves (quantity & spacing) and whether or not I will need baffles.

  4. sunman76

    sunman76 Master of the Pit

  5. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Robb, morning..... That is a cool panel..... It will make a great smoker.....  Consider using the AMNS, AMNPS or the AMNPPS from Todd....  A pipe burner sound like a great heat source....   Call Todd about which smoke gen to use.... He is a straight shooter, and will not steer you wrong..... and you will be very happy with his product as are the hundreds of folks here are....   (maybe thousands)....    Dave
  6. Thanks Dave, was there another type of insulation you would recommend, or will I be OK with the hardie board and using the propane burner to bring it up to temp?
  7. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Hardie board is a cement product that absorbs moisture...  Thermal mass is high... and it takes forever to heat up... I have it in one of my smokers and it is a PITA.... takes forever to warm up and release all of its moisture....  I would suggest rock wool.... fire proof and light weight... put it on the outside and sheet over it with something attractive...  

    Of course, you could try the smoker without insulation.... living in Fla, insulation is not an absolute necessity....   
  8. thsmormonsmokes

    thsmormonsmokes Smoking Fanatic

    How critical is it to sheet over the rockwool?  I've been thinking about insulating my Chargriller for a while, but I don't know what would be the best material.  This sounds like it could be a really good solution. 
  9. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    You could use the same material that insulators use to sheet over piping in commercial applications..  Rockwool comes in a "water resistant" form also....   I would us a 26-28 gauge metal wrap over it...  Prepainted, baked on finish would be one choice....  
  10. crawln

    crawln Newbie

    Hey I would like to tell you I have a box like yours and it has been up and running from march until now and it has 1/2" cement board in side and it works great. I live in Seattle and we just had 20deg weather and I just made prime rib 7lbs and it was less then an hour to get to temp, I used L brackets t o hold it up in place. I am using pellets and can get my smoker up to 375deg and that is good for the size of the box plus I am using fire brick in the bottom. If you would like to see more email me at [email protected]
  11. Robbs why not use the hardibacker on the outside. This way you can clean the inside easier and any extra moisture will not effect you cook. This is how I did mine and it worked out great. We ended up capping the corners with aluminum angle iron. Just remember this adds a ton of weight.

    Show us some pics when your done.
  12. Insulating with wood on the outside will be adequate.

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