Reverse flow specs ????

Discussion in 'Wood Smokers' started by teeotee, Apr 29, 2008.

  1. teeotee

    teeotee Smoking Fanatic

    I have decided on my design for my brick/rock smoker. In the process i thought why not build a reverse flow.
    My plan is to use a 55 gallon drum laying on it's side and build around it. After reading various posts on rev flow i have a few questions.

    1 - What thickness or gauge should the baffle be ?

    2 - Is it a good idea to have some holes in the baffle or should it be solid ?

    3 - How far below the cooking grate should the baffle be ?

    4 - Is it a good idea to install a drain tube and valve to the baffle plate ?

    The chimney will be a 6" stove pipe with an adjustable damper. Firebox will be 18 x 18 and 24 deep. I'll add some vent pipes to the bottom of the firebox with dampers.

    Any input would be appreciated.
    [​IMG]
     
  2. davidmcg

    davidmcg Meat Mopper

    I am by no means what you would call an expert and have never done a smoke pit like yours, but I do have a reverse flow that I made. My baffle is 1/8 steel and does not have holes. Why doesn't it have holes? Never thought to put any in, didn't think it needed holes. My baffle plate is 6 inches below the grate and about 1 inch from the opening. The key to building your pit is to remember the original design may not offer the results you want and you have to make it in such a way as to mod it afterwards. You also have to have the mindset that just because the initial smoke may not be what you want, that doesn't mean the fifth smoke won't do it. I think everybody will tell you a fine smoker gets better with age. On top of that, few of us who build our own ever get over the experimentation and fabrication stage. To me, thats a bigger and better challenge of smoking up some fantastic plates of meat. After you get that puppy built fire her up and get a good seasoning into it. Then, go get yourself your favorite cut of meat, shoot some before, during and after pics and post them here. We all love to see a work in progress.
     
  3. teeotee

    teeotee Smoking Fanatic

    Thanks for the input david.

    This is going to probably a summer long building project. Due to time and money restrictions but will definitely be posting progress pics. Looking to get the comcrete foundations done in the next two weeks.

    I'm sure there will be some design changes as it progresses. There always is[​IMG] .

    The baffle will probably be removable plate to help in the occasional cleaning. Only reason i mentioned holes was because i read in a post someone had put holes in thiers.
     
  4. richtee

    richtee Smoking Guru OTBS Member

    That was a darn good reply... POINTS!

    Your drip pan IS the heavy metal that directs the smoke around the bottom end up to the meat. You weld a pipe in the middle..or the far end..and tilt is to let the drippings flow to it.
     
  5. gooose53

    gooose53 Smoking Fanatic SMF Premier Member

    Mine is reverse flow and the baffle tilts down from the left where the fire box is. There is a lip of about an inch so the drippings will not go into the heat chamber and the hole is also in the middle with a drain to catching the drippings. I don't have a drain in the heat chamber and think that is a good idea. I don't think the inch lip is enough and will be working on making that 2 to 3 inches tall. Reason for the bigger lip is ease of cleaning....with only a inch lip I think that just begs for trouble by getting water, etc., into the heat chamber (where there is no drain at the present time). I have no holes in the baffle....seems to me that would defeat the purpose of having a reverse flow cooker. Would be glad to answer any questions you have....even though I'm not an expert. Good luck on building your cooker!
     
  6. teeotee

    teeotee Smoking Fanatic

    Thanks for the offer goose. I'll be sure to ask if and when a qusetion comes up.

    The way i'm planning on building this, the drain would be in the middle with a pipe leading to a valve in the storage area underneath.

    I was thinking myself the holes defeat the whole idea but had read it somewhere and wanted other peoples opinions. I do see the benefits in having a thicker plate so it retains heat to aid recovery after opening doors.

    With all the ag equipment around here we do have a local welding shop. Need to go speak to the guy once i have materials list finalized and get a quote for supply and cutting and fabrication of doors, frames, shelves etc.

    Would do it myself but don't have a welder ................... yet, could be a good reason to go and buy one [​IMG].
     
  7. how does the drain work??
     
  8. ryf

    ryf Fire Starter

    welding isn't cheap, the cost of welding it up with you providing cut parts will probably buy you a reasonable welder.. the problem you face is then spending more money learning. that may be worthwhile if you are a tinkerer like me.

    IMO, best advice, talk to some guys you work with, most people know a guy who works on cars and welds, trade service for service, provide beer and Q, whatever, but paying pros kills good projects sometimes.

    If you have to pay a pro, buy a sawzall and grinder to cut with, and do as much as you can do yourself, you are paying a pro A LOT per hour, its cheaper for you to do it yourself and let him weld on it for 2 days, then you paying him for 2-3 weeks of fab work, not to mention, he'll probably be working on it and other jobs as well, so progress will be very slow if he's a small shop. I'd rivet pieces together as much as you can, the welder can fill in the holes when he welds it, and it keeps it from being confusing since he won't know what goes where, you may have to dress a few little fill welds, but at least its the way you wanted it, and you aren't paying him by the hour to figure out what your trying to do. hope that helps man.
     
  9. smok'n steve

    smok'n steve Smoking Fanatic OTBS Member SMF Premier Member

    Keep in mind that if your barrel is a thin gauge and you are building around it with bricks and mortar, that you don't want the barrel to rust out earlier that than the life of all that mortar work. Might want to use a thicker steel since this is a permanent build?
     
  10. Hi Steve
    Im fairly new at this just trying to learn,I cant figure out how a reverse flow can be tuned in to even the temp. If the baffle and plate is one stationary peice, how would someone tune the grill to even the temp front to back?? I ran accross this site and this guy claims to guarantee 5 degrees front to back!? its under http://www.cookersandgrills.com/our_products.html the guarantee is under What is a Reverse-Flow System? Any info would be greatly appreciated
    Thanks
    Ken
     
  11. I would like to ride your coat tails on this thread and hopefully get us both some usefull info. Is there anyone that is willing to post some pics of the internals of their reverse flow smoker. I am trying to gather enough info to begin fabricating an offset and would like to incorperate reverse flow if I have enough data. Thanks
     
  12. ryf

    ryf Fire Starter

    the reason reverse flow evens the temps across the cooker is because the heat warms the plate below the grill, this transfers heat up through the plate, the smoke and heat then come around the plate at the far end, coming back towards the fire box and up the stacks, the air is starting to cool as it shares heat with surrounding air to balance temps, but the plate gets warmer as the air gets closer to the firebox, warming the cooling air and better balancing the system.

    so you have more time for heat to equalize, more metal to balance the heat. its more complicated than that, but without drawing pictures, thats as complex as I feel comfortable with right this second.
     
  13. dennisdocb

    dennisdocb Smoking Fanatic SMF Premier Member

  14. thanks for the links it gave me some cool ideas for my outlaw offset i just got i really appreciate it
    ken
     
  15. smok'n steve

    smok'n steve Smoking Fanatic OTBS Member SMF Premier Member

    To Ken, sorry I missed your question, looks like you got help:)

    and to seldomss, I will post a few pics of my lumpy smoker here, but if you want to see the entire build go to this thread

    Lumpy the Wood Chunk Burner,reverse flow build!
     
  16. hi steve is there anyway to fine tune a reverse flow what can be adjusted??
     
  17. smok'n steve

    smok'n steve Smoking Fanatic OTBS Member SMF Premier Member

    Well, its not really needed, the ease of control of the burn is usually predictable so the next step is the cooking chamber, which is very predictable, so fine tuning in my opinion would be if you have two hunks of meat and one is near the firebox, to be safe, just swap them half way through your cook.

    Reverse flows are very consistent and constant, no hassles, and easy to cook with,

    hope this helps,

    Steve
     
  18. cheech

    cheech Master of the Pit OTBS Member

    Smokn Steve what is the purpose of the X on the door?
     
  19. smok'n steve

    smok'n steve Smoking Fanatic OTBS Member SMF Premier Member

    Because the door is not welded to another side like the other 5 sides of the firebox, its a good idea to add the "x" structure to prevent the door from warping in the future:)

    Steve
     

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