Will this work?

Discussion in 'Reverse Flow' started by inkjunkie, Apr 12, 2015.

  1. inkjunkie

    inkjunkie Master of the Pit

    There is a thread on here where a fellow was asking for help in using his smoker, he is having some troubles with it puffing like an old small block Chevy when he is adding wood. Seveal folks commented that the wood needs to be "preheated" prior to putting it in the fire. I am planning on insulating the firebox. The inner parts of my firebox will be quarter inch. Have a sheet of 14 gauge, think that is what it is...it is about. 080" thick. Will that be sufficient for the outer skin?
    Back to the warming matter..I was thinking about extending the top of the FB a few inches to add a warming area....box would look something like this...
    Someone mentioned the potential of the wood in the warming area igniting. Would only be keeping the next 1 or 2 pieces of fuel in it so it would only be in there for a brief period. The floor of the warming area will be quarter inch, it will actually be the roof of the FB, will be the top of the opening. Firebox will be 16" or so tall, ain't like the flames are going to be pounding the roof of the firebox?
  2. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    As long as the red line is the top of the Fire Box... then you should insulate where the red line is and NOT above it... An insulated box, where you store wood, could, and probably will cause the wood the burn... I have had wood catch fire when stored UNDER the firebox.... wood smolders at somewhere around 500 deg. F...

    Last edited: Apr 12, 2015
  3. lendecatural

    lendecatural Smoking Fanatic

    What about the side of the firebox under the CC, if it won't be insulated, you could put a small wood rack down there and let the radiant heat from the FB heat it up. Since you wouldn't be leaving it there that long, I imagine it would warm up good but not catch fire right away since it is outside the box...
  4. I sometimes set my splits on top of my FB, but for the most part I don't. Most BBQ places do not preheat their wood either.

  5. inkjunkie

    inkjunkie Master of the Pit

    I don't understand this. You are saying that I would need to insulate the top of the firebox, correct? Yet on this thread...


    quoting Gary  "When we finished you could hold you hand on the side, door and back."

    If what Gary is saying is correct and I were to insulate on top of the firebox....in essence the bottom of the warming chamber how would there be enough heat to "preheat" the firewood? Would not be much sense in building a warming chamber that was cool enough to touch....
  6. smokejumper

    smokejumper Smoking Fanatic

    No. I believe he was not saying that you need to insulate the top of the firebox.
    He was saying that if you are going to insulate it, do not put the insulation higher than the top of the FB.
    Or put another way, do not insulate the top (and sides) of the warming chamber where you will place your wood,with the bottom bare, as that is essentiallly an oven that could cause your wood to burst into flames.

    If you must have the warming chamber, just don't insulate it.
    That insulation is not serving the purpose of keeping heat in the firebox anyway.
    I would even have the warming chamber taller so there is volume for the heat to escape and not build up so much.
    Last edited: Apr 14, 2015
  7. inkjunkie

    inkjunkie Master of the Pit

    That is my take on what Dave said as well....to insulate the top of the firebox....which again does not make much sense to me. If what Gary is saying is correct, that with the insulation you will be able to touch the outside of the firebox....and the purpose of the warming chamber is to warm wood...by insulating the top of the firebox you would be stopping the heat from reaching the warming chamber.

    Perhaps I am making no sense? Guess it is time to seek help elsewhere...
  8. lendecatural

    lendecatural Smoking Fanatic

    I get why this is confusing, I think....  I believe Dave was saying even if you have the 1/4" divider, it would end up getting really hot in there and could end up lighting the wood in that chamber. If you didn't leave it in there too long, it would work and I think you have a good idea. If you end up putting a stick on every hour, and put a new one in the chamber after putting the warm one on the fire, you may have a really slick trick going there..... You will just have to figure out how long it can stay without smoldering but that will be very evident, just keep the welding gloves handy and you are good to go.
  9. smokejumper

    smokejumper Smoking Fanatic

    I think you are just maybe getting hung up on Dave's red line or something,so allow me to paraphrase it another way.

    He was saying to not insulate the top of the warming chamber.

    I don't believe he was trying to say any more than that.

    Having said that, you can build it as you designed it. It will work. Just be ready to pull your logs out of the warming chamber if they start to burn.
  10. inkjunkie

    inkjunkie Master of the Pit

    Not slamming anyone here....the problem is mine, being bi-polar, having a pretty good case of persacutory ideation and being obsessed with things makes life difficult. Very frustrating for me to ask a question, get a response and have it not make any sense and then not get any more feed back. Would hate to build this thing, with this warming chamber contraption and have it not work. Very well may scrap the whole project for a while....none of what I am trying to figure out makes any sense.......and seems like finding the answers is virtually impossible....when I do get around to it I  may just keep my mouth shut and go about doing what I think is right.....seems to work better for me with all my mental health troubles....
  11. lendecatural

    lendecatural Smoking Fanatic

     No worries Ink, we are a community of equal opportunity helpers only trying to keep guys from making some of the mistakes we have made. Its all good. I went through engineering school with dyslexia in the days of the slide rule and was married to a bipolar chick, I get it. You have some good ideas, just let go and run with them, the worst thing that can happen is you have to cut something out and get a do-over. That is the beauty of building a smoker, as long as you adhere to the basic air flow parameters in Dave's calculator, it will work, anything you add/enhance that works, will evolve the model and help other guys down the line. Hang tough.
  12. inkjunkie

    inkjunkie Master of the Pit

    Thanks...but I sorta disagree about equal opportunity helpers...seems like lot of folks just ignore certain members threads...it is what it is.
    I may be going to town tomorrow to start picking up supplies for this thing...on the fence about starting a thread about it. Ain't like there isn't dozens of reverse flows based off of 60 gallon compressors. Very frustrating for me to invest the time in a thread and basically be talking to myself...perhaps it is just the depression talking...
  13. lendecatural

    lendecatural Smoking Fanatic

    Fair enough, I guess I'm speaking for myself and I'm not always prompt to answer when issues come up but I do like guys to think out of the box. There is a lot of time that goes into building one of these things, I know, mine is stalled but I hope to get on track shorty if crap would stop getting in my way. My ADD keeps me with more projects than it is ever possible to finish.
  14. inkjunkie

    inkjunkie Master of the Pit

    My head doc always tells me my expectations, of myself and others are far to hIgh. I often will tell someone I will do something for them and it never happens. More often than not my thoughts are clear as mud which leads me to forget things. I asked someone on here if they would help me with this and was told as long as it was in threads he gladly would...well, that ain't happening. Part of my nightmare is a pretty good case of paranoia....put these 2 together and well...

    For what it is worth there is a very good reason I live behind locked gates...and have 0 friends.....I just don't get along all to well with people. When I get frustrated and stressed out I slip into manic state...which means I lash out at folks, more often than not in a black out type of state and literally don't remember any of it. one thing that does really irritate me is drive by answers.

    I have decided to forge on with my project, using the calculator on here...I seem to have better luck getting info from folks on another site so will probably start a thread over there about it...if I end up getting stuck on something. Otherwise just going to keep my mouth shut and do what I feel is right...more than apparent not many folks care enough to lend theread advice..
    Last edited: Apr 16, 2015
  15. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Doug, morning.... My fault.... My explanation didn't go far enough when explaining "my thoughts" on insulating the warming box area..... Sooooo, here goes.....

    If the top of the warming area is insulated, and the top of the firebox is not insulated, the top of the FB could easily reach 400+ degrees.... and the warming box, 300+ degrees....
    With the firewood sitting on a surface that could easily be over 400 degrees F, the firewood could easily catch fire...

    If the top of the FB was insulated with the warming box above it, I imagine the warming box could easily get to 150 ish degrees F or warmer... A good temp for keeping food warm and wood too....

    A rack under the cook chamber, would serve as a wood drying area... maybe about 6" vertical clearance from the rack to the CC and as long as necessary.... BUT wood can catch fire there too.... I've had it happen and if I remember correctly, SQWIB had a fire start in his wood storage under the CC.... under the CC is a lot cooler than on top of the firebox....

    FWIW, insulation is not perfect... heat will migrate through the insulation to the exterior surface... Roxul has a 4.2 R rating per 1" of thickness....
    smokejumper likes this.
  16. inkjunkie

    inkjunkie Master of the Pit

    Going to hold off on the warming chamber idea until I get it partially assembled. If I keep getting jerked around by the local insulation companies that I am trying to get 2” rock wool from I may very well abandon the insulation idea entirely. Contacted a place I found online, with the shipping came out to right under 100 bucks. May just use the 3 inch stuff HD has. Have a few other things rolling thru the spinning mess in my head, but will be keeping them to myself...til I get a chance to investigate them
  17. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

  18. inkjunkie

    inkjunkie Master of the Pit

    Have seen someone on another site mention that prewarming the wood is what gets him the nasty smoke......for what THAT is worth....
  19. I was thinking about this post and ideas for wood preheating and instilating.

    Build your fire box as normal, insulating the sides only.

    Then make a second box the same size as the top of your FB, with the top insulated. And handles on the sides.
    Make the box have an airtight door. Fill with wood. It will cook and heat to charcoal if you let it.

    Once your wood is cooked enough for your needs flip the box over, the insulation now between the FB and the wood.

    You could thread a 1/2" bolt into the door to moniter the wood.

    Like this:

  20. lendecatural

    lendecatural Smoking Fanatic

    I'm not buying what he said on that one..... thin blue smoke (TBS) comes from coals under hot wood.

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