New smoker EATS charcoal- help!

[Ranjer59]

Drew up and built (helped build more accurately) a cabinet smoker: 3/16 steel 4ft tallx24wide x24deep. Equipped with 2 gasketed doors with nice latches, 2" ball valve feeding air - and a 4" square pipe (w/damper) to let the smoke out. Not insulated, not reverse flow- I wanted a "Square UDS" with 3 pull out shelves and a heavy V plate heat diverter/drain pan (did not want the grease in the bottom of my cabinet) Done several cooks on it- the food turned out good (or better) but it's using 3 or 4 pound of briquettes per HOUR! I'm used to my UDS, MiniWsm or my pit barrel clone- I'm not used to using a whole 18lb bag of coal and not getting multiple cooks out of it.

The cooks were done in 30- 35 degree weather- not shielded from the north wind. I know that both must play a factor- but I have no way to get it to a shielded spot (too damn heavy- the wheels are not suited to going "off road" and I can't help the weather.

Tried a welding blanket- does not insulate well at all- tried to use it as a wind block... not sure if it helped at all - hard to tell.
Yesterday, I pulled the Vplate/diverter/grease catcher and ran it again. 30degree day- NO wind/very calm. Started with 15lbs of fresh kingsford- but I pulled the brisket after 4 hours on the grate once it was clear that I would not be able to finish it in the smoker. (wrapped it - popped it into the 325 oven to finish - was great.) weighed what remained of the coal- 3 lbs and most of it too small to be of any worth. (I had partially burned coal all across that basket- it's not burning up completely and dropping thru the expando grate. Problem? dunno)

Need some advice- I like the cooker. Don't want to add roll insulation and reskin it- that's be major in time and expense. Wish there was a spray on coating that would insulate but I'm coming up with nothing that is "practical". I could take some rock wool boards and strap them to the outside and see if that would help. If so, maybe I could come up with something that does not look like a drunken monkey did it. (though they are low- I DO have standards)

[Tom_Heath]

The magic of roundness is just not there. It's square. With that said, are you using a coal basket? If not, you need to.

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[Rodcrafter]

I agree coal does its best when lumped together.


Making memories.

[Ranjer59]

Sorry did not want to throw up too many pictures. I can post more if there are specific aspects you need to see. There is a flat ash pan with a 1" lip in bottom. On legs giving 3" clearance -sitting on/inside that is a 16 x 16 x 5 coal holder with a 3/4 x9 expando bottom. The air intake comes in below the level of the expando. The basket will hold about 20lbs of charcoal... ask me how I know I'm using about 3lbs /hour keeping it running at 275 to 300 in temps of 30-35 with north wind sucking the heat off the steel.

[Pete Mazz]

3 lbs/hour at that size at that temp sounds about right.

[Rodcrafter]

I'm thinking the thickness of the steel is holding the cold from the outside so the charcoal has to overcome that before it can run the temp you want. I'm building something myself that I believe will work here because it doesn't get that cold. But example, Frank cooked ribs in the snow in his UDS this weekend. The UDS is so thin that the fire could heat the drum as if it were in 70* outside, but the drum is blocking the wind off the fire. But in your case, I bet the steel is not even 100* when the meat is in 225* on the inside. I look at it like, the cost of not being insulated. These are just my thoughts, I don't have any real experience on this exact same circumstances yet.

jm2cw

[Ranjer59]

I'm thinking the thickness of the steel is holding the cold from the outside so the charcoal has to overcome that before it can run the temp you want. Agreed. But in your case, I bet the steel is not even 100* when the meat is in 225* on the inside. top 180, sides 140, near firebox 160 (all at 32 ambient mind you I look at it like, the cost of not being insulated. These are just my thoughts, I don't have any real experience on this exact same circumstances yet.

jm2cw

Thanks for the thoughts on the subject, sir.

[Ranjer59]

3 lbs/hour at that size at that temp sounds about right.

Really?
Oh dear God- what have I done to myself?
me: "Honey, I'm gonna need another C note for Charcoal this week."
Honey: "But if you buy the charcoal, you won't have any meat to put on the smoker- so I will go buy more shoes instead- thanks!"

Because I live near Dallas,I thought I could get away with building pure and simple. No insulation, no guru,no gravity feed, no maze of coals. And it turns out I can- I just can't afford to run it

Honestly - it's not all gloom and doom. It will get warm (Dallas, remember?) and the fuel usage will go down to more "tolerable" levels- the smoker COOKS great. I just wanted to get a better read on my situation from the website with "smoker and builder" in it's name.

Thanks gentlemen.

[Pete Mazz]

You've got the equivalent of a 120 gal tank. Charcoal outputs about 9000 Btu/hour. I could see that cooker using 27000 Btu to keep temp at ~300 in 30 degree weather.

[Ranjer59]

You've got the equivalent of a 120 gal tank. Charcoal outputs about 9000 Btu/hour. I could see that cooker using 27000 Btu to keep temp at ~300 in 30 degree weather.

I can find that charcoal briquettes have about 9000btu/pound. I tried to find a way to link the 27000 btu/hour for cooking in that size tank... I gave up. I'm not sharp enough to connect the dots- too many variables. I will gladly take your educated guess for the 27000 btu /hour and run with it- hoping like hell that it gets better the warmer the ambient becomes. I guess if I'm cooking on it for the next couple/three months, I need to see about getting a wind screen of plywood around it at a minimum. I might be able to find some 1" thick mineral wool boards locally- just don't know if the expense and the trouble will be worth it.

Thanks again.

IF I had it to do all over again.. I would have gone smaller... and probably insulated it.

[Pete Mazz]

Wind and cold take a big toll on non-insulated smokers like yours. I'd guess you'd be fine when it warms up.

In my research on verticals, you need about a 1.5 to 1 ratio of Btu to CC volume. In your case you're running at ~ 1:1 which is pretty good.

[Ranjer59]

I don't have a clue how BTUs and volumes work together. If you took the time and figured it out, I salute you! I will take your findings and recommendations - and be happy with them.
I work at a printing company- we use some fluted polypropylene (basically plastic cardboard) that is about 1/4" thick. Gonna get a couple pcs of scrap and fashion a 3 sided wind block to put around the cooker. I'll leave about a 1.5" gap all around the sides-that should keep the wind from stealing some of my heat. Hopefully that simple addition will be enough to keep me from falling out of love until the weather warms.

Thanks again.

[Pete Mazz]

Might even want to throw that welding blanket over that setup. Let us know if it helps.

[Brisket Envy]

Out of curiosity, have you checked the temp exiting the stack?
I am wondering if you might be getting too much volume through it.
When my grate temp is at 225, the exhaust is 150 - 160.

...but, on closer inspection, I see a damper on top of the stack, so I guess you have played with the flow.

Get some inexpensive insulation, wrap it, and see what happens.
If the results are good, get some oven insulation, or other good insulation, and make a blanket that drapes over it.
I got the insulation for mine from a guy who recycles old appliances. For free!

...on the other hand, you could skin it with 16ga or hot rolled 14ga pretty inexpensively.

[Ranjer59]

good ideas- will definitely look into it. I have the windblock ready to go. Will likely NOT try it this weekend (down to my last back of charcoal) I have a 30 gallon drum"hook and cook" rig that I think I will put some yardbird on today. I've had chicken off my smokers and it's good but that "pbc clone" is a chicken cooking machine.

thanks all.

[Ranjer59]

I guess I could skin it on 5 of the 6 sides. But even if the steel was free, I'd not want to pull the door and rework it. Sides/top and bottom would be enuff I'm thinking to get that coal usage down. Maybe for my birthday

[Rodcrafter]

I believe it will take a lot to get her hot because of the thickness of the steel but the insulation would hold the temp and the usage would become reasonable.

jm2cw


Making memories.

[Brisket Envy]

I do have to add, last month I did a brisked on my efficient little one-briskef cooker on a cold, drizzly night, and instead of 12 hrs from a small bag of lump, I only got 7. That one is not insulated, but usually very easy on the charcoal.
As an experiment, if you wanted to go really inexpensive, you could get some of the fibrous ceiling tiles and hang them over the 4 sides, and 1/2 on top in conjunction with your wind break.
That should tell you if the issue is heat loss through the walls.

By the way, I can get 11ga cold rolled for @45.00 per 4'x8' sheet. 14ga hot rolled should be even cheaper.

[Ranjer59]

@Brisket Envy Definitely fuel for thought... and I did consider throwing some drop ceiling tiles on him (yes-my cooker is a "him" ) just to see if it would be worth "moving up". Have to do it when it's cold but not rainy- those tiles do not handle wet very well. (would not be permanent- might not matter ton). I'm excited to give it a whirl. I'm not sure what I'd skin it with... IF the insulation works as hoped, I could skin the outside with almost anything, right? Plastic, aluminum, fiberglass, wood (prob would not do the wood or plastic) but the possibilities are out there.

@Rodcrafter- yep- the skin being 3/16 will take a lot of fuel to come up to temp. That's what I wanted and now I'm going to have to find a way to be good with that. I just don't want to keep losing all my heat to the elements after I get it hot. You guys have given me a lot to think about and I appreciate it.

[Brisket Envy]

I am curious to know what the internal temp of the meat was when you pulled it after 4 hours.

What percent of wide open is the air intake when cooking?
How wide open do you have the damper on the stack when cooking?

[Ranjer59]

Meat temp after 4 hours? I can't say with any certainty - as silly as it sounds. I was doing brisket- I pull at about 4-4.5 hours in at the 290/300 I was running. I don't even look at the thermo until it hits about 190/195. Then I pull the thermo and probe it every 15 until done. being a new cooker, I should have been paying more attention.

my last cook was at 30 degrees with a 15 mph north wind coming square in on the back of the cooker. Air intake? - Wide A$$ open to get it up to 300- then throttled back a hair to keep it in the 280/290 range I like.

I "played with the damper"- but only a bit. I still hope to run it like a big uds- i.e. Full Exhaust and ride the intake tight to control the temps. Folk suggested I try to close it down to keep more heat in. I'm just reluctant to do that- I know the box is tight and It should only burn the coals I allow to burn- even with the exhaust open.

[Brisket Envy]

Well, what's the verdict?

[Ranjer59]

well - the weather has warmed up since December (duh) and I have made about 8 cooks on it.
Verdict is - sucker cooks good.
Running only charcoal- it is a pleasure to cook on- holds any temp I like butttt
It will beggar me to run it for every little cook- getting 6 hours of cooking time (not counting the 40 minute warm up time) out of most of a 18lb of KBB just plain blows.

I have cooked with only wood- fella gave me some nice post oak and it turned out really great. After getting a coal bed goiing, I was running a big chunk about every 30 to 45 minutes.

so- It looks like I have a vertical wood burner. Problem- I don't have a ready supply of wood nor do I really want to keep up with ricks, face cords, 1/4 cords or other wood related quantities.

I might be able to sell it OR go in and pull all the innards out and insulate the interior- that will be a sucky job but if I want to run pure charcoal, that might be my only option.

[Weldun]

just a thought but why couldn't you insulate the outside and add another skin to the outside?

[Dirtytires]

Ok. We agree insulation is needed. Warmer weather is necessary and the wind gotta stop.

Life goes on.

Building a shed for it would help. Even an ez-up with side walls might help.

Another thought, a bit off on the silly side, but could you have it sprayed in bedliner like a truck bed? The material is thick so would offer some insulation and the texture might slow down the wind (on the surface) to decrease heat loss. It would look better than wrapping it in insulation. I don't know that the heat rating is but it be easy to find out.

Other than that, I'd get a Costco membership and ask about pallet discounts.