Building A Reverse Flow Clone

[crossczek]

Hi all,
I am experienced in the smoking arts but am trying to make it to the next level. I'm new to the forum but I've been reading a ton about reverse flow smokers and have had a lot of my questions answered by reading through past threads. But, I still have a a couple of specifics that either weren't answered or I'm still not clear on. Any help would be appreciated.

I'll start with what I've got.
Working on-site to build a new automotive plant I was able to acquire a steel cylinder about 36" in diameter by about 6 foot long, about 1/4" thick.
With some patience and Craig's list I was able to get a bare bones steel frame trailer. I've got a family member that owns a steel fab business and is willing to donate scrap steel and an experienced welder to help me get this thing smoking, if I cook the meat for his company picnic. (There's a no-brainer!)

Now for what I'm doing (or am thinking about doing).
I'm putting the fire box low to one side (obviously). How big should the opening be between the fire box and the cooking chamber? Any recommendations on the size of the fire box? I was thinking 24" square with 1/8" thick material.
There seems to be a pretty varied opinion about hot spots and even cooking temps through the length of the chamber. Some recommend elevating the low end of the baffle (with the drain tube) so the heat flows more evenly during the smoke, while others swear by the usefulness of the hot spots. I plan on making mine level with the chamber so I can tilt it one way or the other depending on whether I'm cooking on it or cleaning it, or if I want hot spots or not. Thoughts/comments?
I was thinking that the baffle should be about 1/4" thick to really hold and dissipate the heat evenly. Suggestions?
How close should the baffle be to the open end, opposite the fire box - I was going to leave about 6" open.
I've seen and read where some chimneys are flush with the top of the cooking chamber while others go right down to just above the cooking grate. I think I'm going to have mine come down to the cooking grate to allow the chamber to fill with smoke before it gets pushed out. Thoughts?
Finally, one door or two? One would allow for half/whole hogs to be done but would really dump the heat when opened. Two would be more convenient but eliminates the ability to go whole hog. Decisions, decisions...

Sorry for the lengthy post, but I think I can get all my questions answered with all the great experience in this forum.
FYI - I've never seen a reverse flow in person, let alone an authentic Lang.

Thanks in advance to all, and I will post pic's as the project develops.

 

[pineywoods]

Heres a link with some good info for ya

http://www.smokingmeatforums.com/for...4&postcount=21

 

[crossczek]

Thank you very much Pineywoods, and that is a mighty fine wealth of information. In fact, my wife is sick of me sleeping with it underneath my pillow. What I'm also looking for is some opinions from people out there that have reverse flow smokers and what they would do to change theirs, or what they would do if they were to build one from scratch. Even what they love about theirs and to make sure I include it in my design.

I picked up the steel today and it's actually 8' long and 3/8" thick - a real monster. I can almost smell the smoke gently rolling out...<sigh>

 

[g3automotive]

here is a few pics of my lang clone let me know if i can help !!!
http://usera.imagecave.com/g3automotive/cooker2.jpg
http://usera.imagecave.com/g3automot...demycooker.jpg
http://usera.imagecave.com/g3automotive/summerbbq2.jpg
http://usera.imagecave.com/g3automotive/summerbbq3.jpg

i cut my cooking chamber just under 1/2 way to alowe for the heat baffle and the cooking greate . u wanta decint opening so u get a good draft ! my fire box is 24" by 24" and i went 3/8 thick which im so glad i did . your fire box will take alot of heat and the thicker the better 1/8 is to thin in my opinion ! the cooking chamber on mine is 1/4 " also and i feel that is a good thickness ..let me know if i can answer any more questions ! jerry from ohio

 

[crossczek]

Thanks g3 - A picture is worth a thousand answers.
Nice job on the smoker! Any second thoughts? If you could modify something from start, what would you change or do different? Have you ever done a hog on a reverse flow?

I had already talked myself into using at least 1/4" for the fire box, your comment just solidified my thoughts.

I see you're from Ohio. Any chance you're from the Toledo area? I'd love to see a reverse flow in person.

Thanks again for the reply!

 

[geek with fire]

It sounds like you are going to have one nice monster on your hands. I guess one thing I'd be worried about is making sure that the trailer is stout enough to handle all of that steel. 3/8" steel of any size has got some weight to it.

Also, if you have a good welder helping you (and it sounded like you do), I'd suggest getting some pretty good sized stainless rod for grate material. Weld them spaced eveninly for a solid grate that will hold heat better than expanded metal, and make it much easier to keep clean.

 

[crossczek]

Ya, it'll be a monster for sure. The guy that loaded it said that that piece was at least 800 pounds alone...not to mention the fire box, grates and everything else! I'll probably cut it down to just over 6'. I'm undecided on weather to cut one large door (for the added ability do do whole pigs) or two smaller ones. Maybe one 4' and one 2'. Suggestions? The trailer I have is pretty beefy and has leaf springs...though, it'll be a while before I tow it down he expressway with any confidence. I may keep my eyes open for a used pontoon boat trailer.

I'll see if I can get my hands on the stainless rod, it may have to be a post fab mod as I'm sure it won't be cheap or easy to come by. Thanks for the suggestion.

 

[g3automotive]

homerville ohio 44235
welcome anytime !
all i can say is research and lots of it ! my cooking chamber door is abit larger than ben lang builds his . so im not struggling to mop/spray and move stuff around . my cooker will hold around 100lb pig but 70- 80lb is ideal . i also used idea's from a cooker called medeow creek like for example my toggle latches that hold my cook chamber door closed and my firebox door closed .my cook rack is removable and it makes it nice when cooking hole hogs but i rarley move it in and out on normal cooks . my heat baffle has a slight angle down towards the 2" drain pipe so grease flows during the hole cooking prosses even when i have the cooker slightly elevated in the noses to even out temps depending on weather wind . you will be very surprised how much grease is renderd from 10 plus shoulders over a 12 hr cook. you wanna try and have that exiting the cooker at all times durning the cook in my opinion
im a welder and i gathered all my steel stock and had allmost everything on site when i started the build . i figured about 3 fulldays tops to build it i had all my plans and 90% of my steel and everything figured out on paper except i never saw a lang or medeow creek cooker in person . so there was some guessing involved in my plans ...lol well after the 10th full day the wife came out to the shop and was like my god jerry what are u doing ???? so i was off alittle in my thought procces of only 3days but it turned out killer and there is no better feeling to fire it up and whatch it draft and mantain temp and only be off 5 degrees from end to end .
butt i started this project becuze i didnt wanna spend 3500 plus shipping from georga and i didnt wanna wait @ the time 3 weeks plus to get one from lang . so it cost me $800 and 12 days of my life i wood love to have back . and other than saying hey i built it to people when were cooking bbq for a group of people or friends standing around drinking beer . next time i think ill just pay the money and buy one ...lol sorry i spell like a 3rd grader . let me know if you need any thing .

no i wood do nothing different ! except buy one next time ...lol

 

[smokedcaveman]

Cross - suggestion for your door problem...how about a 'two in one' door? cut the single door, then cut it in half again, install an overlap over the back of one, leaving the other one to open freely. Install a latch-bolt to 'lock' them together, so that if you want to open one, just leave it unlocked...if you want to go 'whole hog', you just throw the latch bolt, (or bolts) which secures the doors together, and lets you open the whole assembly?

 

[crossczek]

Thanks for the invite Jerry. I used to get down to Mansfield quite a bit but haven't in a few years. (It looks like even that is about an hour away.) And, I don't think I will in the next 2-3weeks either, which is when this thing is scheduled to be done. I was hoping that you'd be a lot closer! Oh, well.
I am trying to do a lot of research but my only resource in on-line and have only been getting bits and pieces from posts here and there, and a few pictures of course. Nothing with any substance until you. I thought that if I asked 10 people for thier opinion on what to do with a reverse flow I'd get 12 different answers, but I got nothing. It's rare to ask for opinions and not get any!

I could tell that whoever built your smoker had some skill and took pride in thier work. Again, nice job. I hope mine looks as good when it's done.
I'll take pics and keep the forum posted to it's progress.
If you can think of any other tidbits or design specs, please keep them coming!

I posted a message earlier today under the "Pork" forum asking if anyone had any experiance with doing pigs on a reverse flow. Maybe you could reply to that and give some advice? THANK YOU VERY MUCH!

(I've already got a guy that wants me to do a pig for him at a Michigan tailgate, and I don't even have my smoker yet and I've never done a pig before!)

 

[crossczek]

That's a great idea Smoked Caveman! I know exactly what you're talking about.

Anybody know how long a 100# pig is?