Homebrew Cold Smoke Generator

Discussion in 'Propane Smokers' started by fasteddie, Jul 25, 2009.

  1. fasteddie

    fasteddie Fire Starter

    rimfirerifleman likes this.
  2. eaglewing

    eaglewing Smoking Fanatic SMF Premier Member

    I must say that's pretty cool... [​IMG]
  3. fire it up

    fire it up Smoking Guru OTBS Member

  4. meat hunter

    meat hunter Master of the Pit SMF Premier Member

    Way cool. I'm constantly impressed by what our members come up.
  5. bbq engineer

    bbq engineer Master of the Pit OTBS Member SMF Premier Member


    Nice work. Let me be the first one to give up some Points for your ingenuity...[​IMG]. (If you check your user cp, you will see that you now are on your way with a great reputation).

    I haven't seen you around before, but in looking at your few posts, you are definitely a great addition to the forum. Please make a post in the roll call section and tell us about yourself so we can properly welcome you to the site.

    Way to go!
  6. beer-b-q

    beer-b-q Smoking Guru OTBS Member

    Great Job Eddie...

    I have one question about the construction, Where and how does the SS Mesh work and go in?
  7. fasteddie

    fasteddie Fire Starter

    Wow! I had no idea...

    The mesh goes in just above the aquarium pump air inlet at the bottom of the mug, so that the air is free to circulate through the wood chips/chunks. The principle is like continually blowing across a smoldering piece of wood.

    Some smoking processes involve burning wood in the absence of oxygen (this is what you are doing with a smoker box, or by wrapping wood chips/chunks in foil...you are restricting the amount of oxygen supplied to the burning wood, as well as protecting it from an open flame).

    Wood burned in the absence of oxygen creates charcoal, which is why so many of you have noticed that wood consumed that way resembles lump charcoal. On the other hand, wood burned with an adequate supply of oxygen is consumed completely and leaves behind only ash. The idea is to control the amount of air flow so that the wood merely smolders and does not ignite into an open flame. What you have left should be a small amount of ash.

    Additionally, the concept of burning wood in an adequately supplied oxygen environment is that, by controlling the amount of air, you can control the amount of smoke...ie, the more air supplied, the more smoke (and heat) generated, the less air, the less smoke (and heat).

    Controlling the smoke independently from controlling the heat...now that offers some tantalizing possibilities.

    Other considerations are that the wood chunks to wood chips ratio needs to be adjusted so that the smoker becomes self-sustaining, and this depends on the size of the container. Bigger containers can feed bigger chunks and fewer chips, and conversely, smaller containers need more chips and smaller chunks.
  8. tacman

    tacman Meat Mopper

    What a great idea... I think I hear my wife's head shaking already...at least until she tastes the fruits of my labor.....thanks for sharing.
  9. beer-b-q

    beer-b-q Smoking Guru OTBS Member

    Thanks for the reply Eddie, gonna give it a try.
  10. mossymo

    mossymo Master of the Pit OTBS Member SMF Premier Member

    That looks just like The Smoke Daddy "Big Kahuna" I purchased off eBay, except you have a third the cost into it; nice work !!!

    Look up eBay item # 160349113851 to compare to The Smoke Daddy.
  11. fasteddie

    fasteddie Fire Starter

    With all due respect for the Smoke Daddy, and because I was unable to find a stainless steel coffee mug for less than $15 online, I am making mine out of a 12" piece of 3" Sch 40 6061 aluminum pipe purchased from Online Metals. Speedy Metals is another online vendor that I have used for small pieces of metal.

    Why 3" Sch 40? Because the end caps are nothing more that 2 7/8" cast aluminum chain link end post caps, available at HD or Lowe's, which are designed to fit over a 2 7/8" pipe, but they are very, very close to fitting inside a 3" Sch. 40 pipe, which has a 3 1/16" inside diameter. A little work with a Dremel and a sanding drum to remove the welded seam inside the pipe on the ends is all it should take. I bought two caps for about $3 at a local fence supply.

    So make a SS screen to fit snugly inside the pipe and tap the lower cap in place below it. If the cap fits loosely, use some high-temp silicone to glue it in place, or simply drill and pin it. The upper cap has a wooden knob attached to it and should fit loosely so that you can remove it to add wood chips. Drill and tap the lower cap for the fitting, or drill through with a drill slightly larger than the fitting's thread size and use a couple of close fitting washers with a pipe coupling as a nut on the inside. You can do the same for the outlet fitting. You can actually take a black pipe coupling and saw a slice off of either end to use for a nut if you like, or there are pipe nuts available (McMaster-Carr), or even conduit locknuts will work on the larger sizes.

    Don't use cadmium or galvanized pipe for this project! These are toxic coatings that might taint your food. Aluminum is ideal because it dissipates heat rapidly and doesn't rust.
  12. fasteddie

    fasteddie Fire Starter

    Thanks so much for the kudos!

    I've got it assembled and tested and it has greatly exceeded my expectations. Once the generator gets going, a very small change in the flow of air is enough to go from thin and wispy to billowing clouds, in a matter of very few minutes.

    I like to start it up with the air control turned up and once it gets to smokin' I dial it back down to where I like it.

    It has worked so well for me that I took Fire it up's suggestion and posted the construction details, along with a short video of it in operation:


  13. gnubee

    gnubee Master of the Pit OTBS Member SMF Premier Member

    How long a smoke does one fillup last?

    The big kahuna takes about 4 hours to burn out.
  14. fasteddie

    fasteddie Fire Starter

    It really depends on the amount of air flow and the proportion of wood chips to chunks (chunks take longer to burn than chips, but produce less intense smoke).

    I had one smoke during testing that went over 3 hours. From what I see, you can make the tube virtually any length you desire, so I think extremely long smokes are possible with longer tubes. There is very little ash produced so I don't think ash buildup would be a concern, but what might be an issue would be the ratio of wood chips to chunks, from the standpoint of "feeding" properly and the smoke being self-sustaining.
  15. dutch

    dutch Smoking Guru Staff Member Administrator Group Lead OTBS Member SMF Premier Member

    Since you didn't show an inside shot of the coffee mug I take it that the burning briquette goes into the bottom of the mug; the mesh screen goes ontop of the briquette and the wood chunks/chips go in last.

    If that don't beat all! [​IMG]
  16. the dude abides

    the dude abides Master of the Pit OTBS Member

    Yup, same here. I've been trying to figure out a good and cheap way to try smoking some cheese this fall. I think this might be just the ticket.

    Dutch, I'm not positive, but I'm thinking the piece of charcoal and the wood go on top of the mesh. That way the wood is in contact with the heat source. Also, I'm guessing that by using chips, that helps to keep things smoldering vs. igniting since you're burning from the bottom up. So if you didn't have forced air coming in it would smother itself out. And the mesh screen will allow the ashes to fall down through it.

    Sweet idea Eddie, not sure how I missed this one.
  17. rw willy

    rw willy Smoking Fanatic OTBS Member

    Okay, Now off to wal-mart!
    Good looking device.
  18. howufiga

    howufiga Meat Mopper

    That is way cool!! lol [​IMG]
  19. the dude abides

    the dude abides Master of the Pit OTBS Member

    So I'm laying in bed last night and I stat thinking of this little project. Wierd, I know. But I started wondering what those mugs are insulated with. Assumably this will still get hot enough to melt or breakdown a plastic or styrofoam liner. Having used many different style of insulated coffee mugs, I know there is a seam near the lip of these mugs where the fumes from this could and probably would escape. Not to mention whatever type of glue or sealant they use to keep the liner, insulator and cover all held together.

    I don't have any answers to my questions, but just throwing that out there. Maybe a good seasoning burn off would help before using the first time.
  20. bud lite

    bud lite Smoke Blower SMF Premier Member

    I PM'd FastEddie for clarification. Here it is.

    Hi Dale!

    The mesh goes in first, all the way down, so that it is still in the pipe and just above the bottom fence post cap and the air fitting.

    Then put in a layer of wood chips, not too many, just cover the mesh. I buy wood chunks and split off some thin pieces for this, maybe 8 or 10 or so to sprinkle in the pipe.

    I light a briquette and get it going real well, get the white ash all the way around on it, then drop it in on top of the wood chips. Take a few more wood chips and cover the briquette with them, then fill the rest of the pipe with chunks and chips. Turn the air flow up and leave the duct off the pipe until she starts smoking real good (about 5 or 10 minutes or so), then you are good to go. You can regulate the amount of smoke with the air flow once it gets started.

    Again, I split the wood chunks to make chips, so you can get an idea of the size of chips I am talking about.

    Any other questions don't hesitate to ask! Let me know how things go!


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