Great British Smoker

[Renegade45]

Hi Guys,

Im brand new and hoping you can all help me out a bit !!

British born and raised and a fairly established and confident griller ive decided to up my game and build a proper smoker. I never do things by half so im throwing my self in at the deep end and am currently in the planning stages of building a double barrelled offset smoker, with a twist as well as collecting all the necessary materials and tools.

im hoping you can give me some advice as to whether you think my design and theory's are accurate and any tweaks i can make to improve on my design.

So the General idea is making a double barrelled UDS (separate fire box & cooking chamber) but rather the mounting them over/under mounting them at around a 30% angle. My theory is that all heat rises and is conducted, whether that me through the Air or radiating from the Fire box itself. so offsetting the chambers means that only the exhaust gases will be producing the heat thus giving me a more manageable temperature control.

ive also included in my design a Heat and Smoke disperser sat in the bottom of the cooking chamber causing smoke to be forced down and to the bottom of the cooking chamber then directly up ( over succulent meats ) out of the chimneys.

The whole construction will be made from steel and the cooking chamber and fire box being made from 45 gallon drums with Mig welds for all of the fixings. im hoping that with my design i can leave the frame and cooking chambers separate for detaching and moving.

Below are some initial CAD designs to assist you in understanding my ramblings, please feel free to tear it to pieces.

I appreciate for my first smoker this is MASSIVELY over complicated but as the greatest fighting force in the world say (sorry Seals/Delta/USMC)

HE WHO DARES, WINS.













Thanks in advance Guys & Gals !!!

[Tom_Heath]

I need to think about this design for a bit.


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[Renegade45]

Thanks Doc,

Any help you could give would be really great. if you need any additional specs or information please just give me a shout and im more than happy to try and give you as much as i can.

Im currently in the process of finishing another project (no point having an amazing smoker if you havent got somewhere to enjoy the produce) so my build start date isn't scheduled till mid to end of May.

Plenty of time for tweaks and discussions.

[Rodcrafter]

Welcome to the crew, have you checked out the pit calc on the home page? This looks to me like an interesting cooker. I would still think that it would work like an offset. So I would say the Fire Box is too big and the pipes connecting the two will cause a great deal of heat loss.

jm2cw

[Renegade45]

Hi Rod,

No I haven't... and after looking i cant find it could you post a link for me ??

im probably going to place a fire bricks in the bottom of the firebox and place a charcoal box on top of that. contain and direct the heat more efficiently.

why do you think the connecting duct would cause for large amounts of heat loss, assuming the welds are air tight is it a matter of length or volume ??

[Rodcrafter]

http://www.smokerbuilder.com/pitcalc/

That is your link. The thing about remote FB is you really only get a portion of the heat you will be hoping for. The air is rapidly cooled as it goes through the air cooled pipes. I have NO personal experience building one of these. But the only thing I've seen this sort of stuff work well on is cold smoking.

jm2cw

[Renegade45]

Thanks for your response Rod,

ive had a look and the recommended fire box size and mine is about 10 cubic inches too big, im assuming however that's for a directly connected firebox like on a traditional RF smoker.
Would a larger firebox not equal out for any loss in heat in transition between chambers. a little bit inefficient as far as burning fuel I admit, also to maintain the layout proposed what do you think the best solution to the problem would be ??

Reducing the surface area expose to exterior airflow (barrels closer together with shorter pipes) ??

Insulating the tubes with some exhaust heat wrap tape ??

i would like to maintain the frame and layout if possible to keep to cooking camber hight as low as possible. Most of the over under double barrel set ups ive seen look like they have a cooking chamber in excess of 50", im planning on fabricating a removable coal box that will sit directly on top of the smoke diffuser for when i want to quickly grill something or for any finishing HIGH HEAT cooking that might need to be done. doing that at mid chest levels is not something i want to be doing if its avoidable.

Really appreciate your help guys.

[Rodcrafter]

You said;

"I've had a look and the recommended fire box size and mine is about 10 cubic inches too big"

The sketch made the FB and the CC look the same size. So that is surprising, about the pipes I would put them out of the equation touch the 2 chambers together, and cut an opening between them of the right size based on the calc. I say that because anything else is "uncharted water" and it would be trying rather than doing.

jm2cw

[Renegade45]

Rod, Definetly some good points im already going to take on board some and make some tweaks.

With the smoker box beign too big what effect is that going to have on my cooking chamber ? is it going to burn to hot or is more a case of being inefficent ??

i admit that on my CAd design the 2 chambers are probably further apart then the would be once constructed but i wanted to clealy show the inlets for the cooking chamber. i reality these will probably be 5" in diameter and 3" long maximum most of the other double barrel smokers using an over under design have a similar set up and i know the flanges on the Vogelzang kits ( i appologise if i just blasphemed but i do like the premade baffle plates they make) are about 1.5" in length so assuming 2 of those with a connecting pipe would be the same, kind of ?? however i will try and get them as close to each other as possible to minimise the air cooling affect.

ive also seen a few guys line the firebox with Firebricks so i thought i would addopt this approach to insulate the box. idealy i dont want to start chopping apart the second drum and then try to stitch it back together, the more cuts and welds i put in the more of a chance of an air leak in my mind ??

im wondering if the increased heat produced from the oversized firebox will cancle out the cooling affects of hot air and smoke travelign through the inlet pipes ??

[TheHC72]

How's the build going? I've been thinking in the same ways, but with propane tanks and modelling a bit, more old school than using cad... as someone mentioned above, my idea is to connect them directly. Also to use the lower box as firebox and for direct grilling. The problem that I am tinkering with is to control the heat in the smoke chamber, perhaps looking at baffle design used for mufflers or similar.

ghetto-cad-BBQ-model

ghetto-cad-BBQ-model-2

[Tinker]

I actually built one similar to this design and it did work well if I may I would suggest to get the firebox to a more appropriate size use a smaller diameter pipe but keep the length close to but not the same as the main cook chamber and make the heat transfer tube one solid tube and I would use the pit calculator for the fire box to cook chamber throat to figure how big to make the heat transfer tube I also would try to make the transfer tube run the length of the fire box and also keep it short between the firebox and cook chamber that way you would have minimal heat loss and use 1/4 plate to make your transfer tube the baffles you have in the cook chamber look nice I think there are some post on here somewhere about designs such as this I think they are referred to as center feed I like your concept keep us posted