Using a metal shed for cold smoking + ventilation / chimney question

Discussion in 'Smoke Houses' started by smokeway, Jan 28, 2013.

  1. Hi

    I wanted to ask the experts on here if my idea was sound or had any major failings.

    I need more space for cold smoking. I'm thinking of buying a metal shed (weather sealed) and using the cold smoke generators I already have (or just an old fashioned pile of sawdust(. What I want to do is buy the below metal shed, place it on concrete, rodent proof it, air seal it, install an adjustable air intake at the bottom and install a (adjustable flow) chimney.

    Will this be OK in terms of health or common sense? The heat in there will be under 20 degrees C and I wont be putting the smoldering sawdust near the paneled walls, so I don't think there will be a health risk from the metal. It also wont be in direct sunlight

    The second question I wanted to ask was about the chimney. If I attached ducting and elevated it so it terminates about 3 meters up the side of a wall, would the air pressure be enough to draw enough air through the shed? I'm thinking as you get higher the air pressure is a bit lower and thus if you have a high chimney, you can get better air flow?

    This is for air flow but also to maybe reduce the smoke smell by elevating the exhaust to nearer the roof and it can blow away

    Appreciate any help you can give. I will post photos when I am done
    Last edited: Jan 28, 2013
  2. jirodriguez

    jirodriguez Master of the Pit OTBS Member SMF Premier Member

    Also keep in mind that metal will not breath like wood does - specifically you may see moisture build up on the inside during smokes. With wood any moisture would generally be sucked into the wood, but metal will just bead up and either drip (form the cealing) or roll down the sides. It won't happen in all weather, but the slight amount of heat from cold smoking may be enough to cause that effect.

    So if you are trying do something like smoked salmon, where you are looking to dry it out a bit, you may find it harder to do.
  3. thanks, that's a good point.

    I wonder if there is some sort of food safe, fire proof but absorbent lining I could use?

    Or would wiping it with towel daily/ after every smoke help?

    appreciate your help
  4. jirodriguez

    jirodriguez Master of the Pit OTBS Member SMF Premier Member

    It has to do with insulation - like a toilet tank when it "sweats" do to cold water inside but warm air outside. If you could insulate the outside of the shed real good it wouldn't be prone to sweating. Also make sure you have good air flow.
  5. I understand, thanks mate
  6. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Johnny has you covered.....   Metal sweats... You could heat it, and insulate it....  

    I would build it out of tongue and groove pine.... 

    Draw your plans with all the measurements....   Go to the Big Box store and have them cut all the pieces... number them as they are being cut.... screw it all together and smoke great food....  Cuts usually cost 25 cents or less depending on the person who helps you...  Show them you are buying all the materials there.... Show them your plans.... get them involved....  and then maybe he will come help you assemble it for a beer or 2.....  all you would need is a screw gun and screws...   Dave
  7. Thanks Dave

    I'm going to be doing some gentle cold smoking - If I'm only burning about 50g of dust an hour, is there really going to be enough of a temp change to cause sweating?

    More info in case it helps - I was planning on using 2-3x 8 inch square smoke generators (2xamaze n smoker and maybe the pro-q once I've cleaned it) placed evenly, below baffles with the chimney being central and having an adjustable flow. I'd probably put 3 intakes with an adjustable grate/door. These are simply metal mesh trays that sawdust sits in and smolders.

    For some reason I had discounted building a wooden one. I think it was because I wasnt sure how to roof it and how to weather proof it without using some poisonous treatment. Also, I felt the metal shed would keep rodents out better and be more easily sealed so i can direct the smoke and smell upwards. If you can think of any suitable links to wooden builds I'd definitely check them out though.

    As for the other comments - I live in London UK so you don't really have that level of customer service and convenience unless you're mates with the local carpenter/hardware store. This also means our weather is about 10-22 degrees C for the whole year
  8. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    smokeway....  Oh...  Please fill in your location in your profile.... that will help us to answer your questions....  A stop into "Roll Call" will get you a proper welcome from our members also....

    I have heard the humidity it pretty high on the island...  If you use a metal shed, I would not seal it very tight...  air circulation and air flow is very important in the smoking process.... air circulation will also reduce the condensate on the ceiling and walls...  also you do not need heavy smoke... Thin, light, wispy smoke is best for great smoke flavor... We call it TBS... thin blue smoke....  Build the metal shed and give it a try... Heck, cardboard will insulate it... (corrugated fiber board)....  Folks use the amaze-n-smokers in cardboard boxes for cold smoking here.... cheese, butter, almost anything can be cold smoked.... 

  9. doctord1955

    doctord1955 Smoking Fanatic

    Maybe a fan would help since its going to be cold smoke?
  10. Thanks again Dave, lots of stuff to think about

    doctor - definitely thinking about a fan, but I'll see how I get on without it - I've seen some old seaside fish smoke houses in the UK and some are pretty basic, no equipment; so I'll see if I can get away with that

    Can anyone tell me what they think of my idea with the chimney? WiIl having a long tall chimney duct help the air circulation or hinder it? I'm going to mount a 1 or 1.5m bit of duct vertically and attach it to the roof or top or one of the sides. The idea is also to minimise smell

    Thanks for all the help
  11. Having thought about it, I am not sure the metal shed idea is sensible. These things are all covered in some sort of plastic resin. Maybe I am being over cautious seeing as I'm only cold smoking but better safe than sorry, especially if I'm making stuff for other people.

    Now I am mulling over whether to make a wooden shed or buy one...

  12. txfshrmn

    txfshrmn Fire Starter

    I am going to build my own wood shed for cold smoking. then paint the outside with Thompson's deck sealer while seasoning the inside with the smoke
  13. oohsam

    oohsam Newbie

    I have an idea. 

    Why don't you use the shed still, I think its ok, however you can put a frame up inside the shed and insulate it, and then cladd it with some pine flooring boards or something. The pine boards and pine wood for framing in australia is real cheap i assume its the same over your way. 

    something like this , this is just as steel shed with some framing inside and some insulation wrap. You probably wont need fibreglass or anything since  ur cold smoking..


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