Stumps mini clone from existing box 24% over

[LeonardK]

Hi I'm Leonard
Started building a simple vertical grill 24x24x38 of 3/16 steel, found a few reasons to stop; reading about new different smokers.

Finally I decided the GF Stump sounds best, set it and forget it, efficient, and almost doesn't need a guru or pid

So to be sure, the coal chute is not in the diagram/pic but I will add that and the ash tray after deciding for sure about dimensions

THIS IS SURELY GOING TO BE A CONVENTIONAL STUMPS CLONE WITH A COAL CHUTE AND EVERYTHING ELSE, NOT A VERTICAL GRILL

I had planned to use a simple cheap control starving the fire slightly with damper and vent so it would depend on a fan, use a WilHi device $30 at Amazon, plug into AC -- set lo and hi temps --- just set a common fan in front of vent.



Now I have mostly all the wrong stuff (.25 and 3/16 plate, angle, 4" pipe, plenty rods, need fluxcore for this), but now I still want to use it and see if I can just bend or push the limits of the proportions a little bit and still get a good working GF Stump 24% over volume of the mini





I figure and please tell me if I am wrong, but, with 1" insulation, to the degree you feel heat on the sides while running, if I insulate double, I thought this might give me the gain I need to keep the same fire box size of the mini (est 5x6x9 inches)

My tentative plan is in this scale pic, no need then with all this going on to get a plan because I wouldn't follow it anyway. Wanting to use what I have and liking going a little larger anyway.

In an effort to make up for the volume difference and not burn more or make bigger fire box, I'm planning to insulate more like 1.5 to 2", but yes I figure even at 100% effy and no losses, one loss cannot be helped goes out the stack

In the future I might try a fun trick recirculating smoke back into the pit with a ducted fan, but that can wait.

The critical thing will be fire box size,( is it as I figured 5x6x9? or bigger ) ; and maybe if yall are setting the air feed valve mostly closed this makes me think I could just run with a little more air and pack just a little more coal if needed.

Those that have the minis, do you find air valve mostly 20% open for average 250deg smoke?

That mini RichB made looks good and how efficient on the coal, 3# runs for 5 hours.

Let me know if you think this will work, otherwise I guess if 24% is too much I'll cut box down or make Fire Box bigger

Thank you and this has been real interesting reading in forums, looks like the Gravity Feed Smoker has only been around since about 2015?? Really cool way to cook. I know I have found IT!

Leonard

One more, been welding with 3/32 -7018 but wanting to get .035 fluxcore wire, reading amazon reviews, and youtuber claimed INE worked better than everything else (Lincoln, Hobart, etc), then in his vid comments other welder mentioned Blue Demon works better, it is cheaper too, so I thought bout buying some Blue Demon .035 in 10# role.

Claims are others are horrible burn thru, poor starts, not fusing at all, you name it

What I read makes me want to use Blue Demon or INE

On flux core what do you find is true?



there's a picture post problem, script does not appear to be working

[ajfoxy]

Welcome.
Are you thinking of building the "stumps clone" gravity feed type smoker or a cabinet style smoker? I did not see a charcoal chute on your drawing.

[LeonardK]

Hi AJ
Glad to hear from you and now I'll fix that

Definitely this is the conventional Stumps Gravity Feed Smoker with the charcoal chute, I'm just making this up as I go along, something different might change dimensions, and thought I would see how big I would make the Fire Box

Some say that bottom rack gets hotter, my 38" box is short but I set the heat diffuser 7" below bottom rack so meat might not burn there, space to bottom of box looks shorter, but might be OK

Critical thing here is to decide on this 1st plan, that 24% oversize Cook Chamber will work with a 5x6x9 fire box, what I think the mini has for internal space, then just put the chute and ashtray where ever they fall and decide leg length


I may just make fire box 6 x 6 x 10", chute probably out of 1/4" plate, FB definitely 1/2", and really that rebar grating is a super idea



Would someone here tell me the internal firebox dimensions for the Stump GF mini?

[Chromeski]

Sounds like you have a pretty good idea of what you want. I'm interested to see it come to life

[ajfoxy]

Now not to put you off doing your own thing, but there are plans for three different sizes of GF on smokerbuilder.com.
Nice thing about the plans is they tell you exactly what size everything is. And 1/4 for the chute and 1/2 for the firebox is right. And I think you might get away with a 24% oversize cook chamber. Of course if you are looking for large then the Double Pan GF is the way to go.

[mp4]

1" of insulation will not be enough. The mini I have had 1 1/2" and you wouldn't want to hold your hand on it for too long at all when its running.

[LeonardK]

Hi
Thank you mp4, been thinking insulation is important to keep constant heat.
First found superwool 25 square feet $200 Amazon, ans any Q you got w/ their graphs except WHAT'S THE R FACTOR PER INCH!
So I hadn't looked enough, found better prices.
BBQ SmokersSupply.com RockWool: 2"x 2x4 foot pcs 7 total 56ft^2 $119 a little extra, needing 40ft. (631)648-3403
Zorro RockWool: Roxul 1200deg F 2"x2x4foot $15.47 sheet 6 sheets $92.82 for 48 sq feet (855)289-9676

QQQ Appears 3.0 to 3.3 per inch R factor (per BBQ smokersupply.com), is this really what we like, found it, no need to look further? Total R factor 6 to 6.6 for 2" Rock Wool.

I like pics and comprehensive explanations too, went bought all steel for chute, Fire Box, ash box
Was going to assemble temporary on angle iron legs, paint, let stand bare till I found ins total about $100, thought I might wait till I get back to work and buy some better components. .035 flux core wire, wheels. May still use bare for a while.

Planned to use what I have, 3/16" and 1/4" sheet and 4"pipe various angel sizes and couple sheets of heavy and light expanded metal.
Insulation 60# est, 16ga sheet 100#, On calculating est weight to 485# still needs stack+damper total guess 500# for sure

Guessing on yalls 16ga inside and out plus FB, your minis come to 350#?????

Is this about right?

QQQ Next is paint, started on 24x24x38 using 3/16 sheet painted w/ Rust-Oleum High Heat 1200deg Home Depot, anything for better preservation or is this good enough to really last? This will be inside after insulation and 16ga sheet, paint that too.

Could yall post pictures and explain how you seal the feed thru for sensors from Guru to Cooking Chamber? Many people have variations in spite of having bought plans. The 3/4" pipe looks like enough. I have seen one or two using what looked like 3/4" pipe as feed thru but then you might use BBQ felt like on Home Depot grills or thicker Lava Lock Nomex Gasket or just plain old fiberglass around your cables? Make a simple split plug of heat resistant red RTV?


About edge sealers cheap good economical locally available like that felt you see on pits at Home Depot or other stuff.

QQQ What stores where would have what kind of stuff?

I certainly plan to make all openings fit tight as I can so even that thin felt stuff might work


OK about the stack, making mine using 4 inch pipe and instead of a plain disc for damper on a machine screw, I thought about the wind pulling the smoke out of the damper like paint from the draw tube on a paint spray gun; so considering a "skirted damper" about 2" over diameter and 2" deep. Any thoughts, do you notice the wind affects the consistency sometimes drawing the smoke out?
Also we have china berry trees, like to keep something completely over the stack even when cooking.


Next, build that chute, Fire Box, and Ash box


Leonard

BBQ paint 1200deg pikk.jpg

Screenshot_2018-08-30 2 Rock Wool Batting BBQ smoker Insulation (mineral wool) 48 x 24 7 piece pack 56 q ft BBQ Smoker Supply.png

thin black BBQ felt on Home Depot pits.jpg

[mp4]

Your paint choice is tried and true.

As for temp probe access...I use a 1" fire rope used on wood furnaces to plug the pipe once the probe wires are installed.

You might want to look at heater meter for fan control. I have no working knowledge of them but I think it may be right up your alley. It's a "build it yourself" system that you may like.

[LeonardK]

Just came to me, an idea from others posts about water tank to drip and supplement a moist smoke.

Some have mentioned some kind of internal vat you fill that drips onto grease dripping pan below, but if it's internal, you cannot clean it.

Now how about a 1/2 inch pipe comes straight down from top spaced 2" from side of Cook Chamber and Fire Box, drip pipe positioned top of sloped drip pan and for dependable metering, a small needle or ball valve or something at bottom just before the ell turns into CC, put a 1/4" piano wire on handle to stick straight out front near Air valve.

This straight pipe could be cleaned out with another piano wire and bristled coffee cleaner or similar

At top some kind of grommeted or threaded connector that would meet a water pan that could be cleaned, so then the water would drip and make moisturizing steam for the meat.

Is there a much better idea already that people have used or a better method for water drip moisturizing steam smoke ?

There could be; does it make a bad taste if some ash falls thru and mixes with your steam in the drip pan ?????????????????

If this is the case, a narrow pan and drip spout could be positioned above on the heat diffuser.

So what about water steam drip? Any ideas, other posts showing build application? At times I have had some dry stuff from the grill, having the option built in could be nice.

[towtruck]

Not sure the benefit. But..............iffin I was going to build a dripper it would all be external except for a pipe to carry the drip into the CC. The dripper could then be monitored from the outside and the valve would stay cool and clean. An air gap from drip valve to inlet pipe so you can see the drip and the inlet pipe is straight so a rod could be shoved down it to clean it. We used to make wood stoves that burned our used engine oil from the logging trucks through a dripper into the FB the same way.

[LeonardK]

Hi towtruck
Well then, a plain pipe has to turn into the CC so cannot be straight. If I had an flame torch I'd bend but have a plasma torch, heat n beat or shake n bake's little harder to manage, but hey, there's no gas bottle bills. Speakin of... gotta a super upright 30 gal Porter Cable compressor from Tractor and Supply store, $384 out the door. Nice place.

Smoke may be good, but to avoid the water and ash chemistry, just in case, then 45 down on top of diffuser, a small tray.



Does ash and water make a GOOD or BAD taste with the meat??????

Would you for sure want just steam without the occasional ash that might fall over into CC???



Above a container with drip valve connected to the water pipe in the smoker.

Now that's air, water, and fire...sounds like Angels and Demons.

[Dirtytires]

A dripper??

Not really sure why.....I can’t see a benefit to it. But then again I don’t see a benefit to any type of a water pan.

[Chromeski]

I vote to install an I.V. the hardest part will be finding a good vein in your brisket, but once you do then it's a steady stream of whatever fluid you choose all thru the cook cycle. Better call the medical supply place and ask about high temp i.v. hoses and refillable bags.


But if you choose your way it will probably work and it eliminates some of tbs issues with a water pan. Many guys say water pan doesn't help, I've used em don't know if they help or not.

[LeonardK]

Hi
Been away for a while re-thinking size of project, mostly I'll be cooking for a crowd of ONE, me. And being I never really had a nice cooker before but recently bought welding equipment and plenty of steel, considered I really might like to smoke often and maybe not really big batches of stuff. So I don't want to feel the need to have $100 plus of meat before smoking, smoking often for ONE brings up the idea of economy to me. Stumps has a really informative site on the capacity and sizes, volumes of their units and of which, I'm only interested in the BABY and the XL BABY which is our "MINI".


Looking around didn't find anybody building a BABY.


So is the Stumps BABY size really that undesirable? I know I've seen lots building BIG stuff.


My fav things may be baby back ribs, chicken, and whatever else I find out about.

I saw that some owning 18" smokers frequently wanted to upgrade to 22" for purpose of better fitting what they want to cook... average sizes of baby backs 18 to 23" and I don't want to trim anything but fat.

I'm still thinking of building a little smaller in spite of the thread title. Just made a new plan size... box 38" tall, mfrs appears to be 33" internal, so mine does figure 24% over even after trimming face depth down from an even 24" to 18.5" but leaving 38" height not wanting to do so much cutting on something already built.

So that whichever, BABY or MINI size, I would still have the most desirable 23" width best fitting baby back rib size untrimmed.

For those thinking about calculators and what size to make fire boxes and chutes in relation to cooking chambers, Look at stumps mfrs chart, notice the chute size is linear compared to the CC volume of the BABY VS XL BABY. Now calculate volumes of BABY vs XL BABY. Both are linear and vol of XL is 2X that of BABY, so is the coal chute 6# and 12# although this does not reflect usage, that depends on cooking temp, mostly low slow 220F.

If making this a Mini, the scale pic here shows 4 racks, bottom always hotter, could also be used at 350F for grilling burgers.

Sorry there seems to be a really strange problem with posting attachments and seeing what is really posted, it's not WYSIWYG. A big confusing discontinuity.

Bought steel for FB, rails, etc still need .035 fluxcore wire n some stuff.

Anybody think of building something smaller like the Baby, if you cook for only yourself, and might cook like every weekend.

It's really nice, to turn on the back porch light, on a cold November night at 9pm it just seems quieter with a beer and a comfortable chair. In this cold weather I've enjoyed some nice BBQ cooking in the past, but always needed a better cooker/grill/smoker!

See on youtube these videos of the Baby Stumps, it does look kind of small when he puts those 3 cans of biscuits in there on the 3 shelves. And GetSmokin comments after buying BABY, he loves it and cooks every weekend BUT wishes it was bigger. This kinda pushes me toward the Mini/XL BABY size and discussions about needing more rack room for baby back ribs 18 to 23 inches long.

Maybe another thing about size, I liked Delmarvas video on How to Cook Smoked Creamy Bacon Mac and Cheese (on the Rec Tec Pellet Grill)

Just wanted to show you something with that tray of smoked mac n chz w/ bacon, looks good. Watch the video.

Leonard

[Chromeski]

Either size is plenty for one. Just make sure the shelf is big enough for a large cut like a brisket. I don't mind cutting racks of ribs in half if needed, but I'd rather not. Build cost is the real consideration here, increasing cooking chamber size may not be that much because you already are buying the hardware.
Remember coal chute does not necessarily reflect the exact size of the firebox.
Whatever you build let us know I'd like to see your work

[LeonardK]

Two things I'm concerned about and keep on trying to figure out and reduce, the weight built this way, and the wheels, they would have to be big to roll off pavement to grass around to front of garage or back again.

I was thinking of finishing it in the garage but then it might have to stay there, because it may weigh 700 to 800#.

Wheels and axles to hold the load without building a trailer.

Now here's an alternative, build it in garage, put it next to the washer, cut vent hole in overhead, join this vent with the houses oven vent with light tin ducting, make a wye connection to existing roof vent.

Anybody ever did that? Either that or up into attic and 180 back down through soffit to vent smoke and allow flow. Venting may be hot, just have to isolate it around path and make a large tin plate to exit soffit.

Weight, Wheels, Where to finish in case it's there permanently (backyard patio I guess)

I'm still figuring weight and thinking about the tubular steel/light sheet const method forum builds the mini with. Also this is another reason considering building it baby size, might get the weight down.

Sorry, just still struggling with what to do, I know I can just go do it, but then I have to deal with what's done if not planned right.

Already bought FB 1/2" plate n channel. I want to build with stuff I originally bought, and that box is mostly built, just want to cut depth to 18.5" making it closer to Mini size just about 5" taller.

Any links, pics members have for heavy stuff where you can barely get mower thru gate, big wheels, axles, how to make it where you can roll on grass without building a trailer? Maybe more like a wagon with a handle if I want to move it just like I built for my pipe fitter tool box 20 yrs ago. Only gotta use much bigger tougher fatter wheels for possible 700# load.




You know what this IS and HOW I got HERE... it started out as a vertical grill project 24x24x38, fire in bottom and couple shelves for fire, water, 2 or 3 for meat...intended to be a grill, no insulation or other stuff, that would have weighed about 200-250# probably moved with dolly. Then thinking of my love for a better smoke flavor eventually found THIS.



Plan to finish with angle iron framing it with space for 2" insulation all 5 sides then a door. May just finish with only legs a little long and figure out good load bearing large diameter wheels/castors to add later.

If you want show me some heavy duty wheels on your projects that aren't full blown wheels for a trailer or other links/threads/pics where people built heavy stuff with wheels.

Thank You All
Leonard

Fire Box

[Chromeski]

I just bought some steeler d2579 from Amazon for my mini build. They have a 500# capacity, 8" wheels that should roll ok for what I need. I've seen others use golf cart wheels

[Dirtytires]

No...no...no.

If you are going to light it in the laundry room/garage you had better cook enough for the whole crew at the local hose company as the fire department is gonna get called to your house before long.

Outdoor use only.....period.

[LeonardK]

Yah you're probably right about fire, stay safe.

Gonna build it on backyard patio on legs, guess now I'll cut face down to inside depth 18.5" make close as possible to Mini.
How tall is the Mini CC? My guess is 7.5" below bottom of diffuser and total H of 33"

Nobody will steal this, just to HARD to steal!!!

Total box internal space 18.5D x 23W x 38H = 16,169 cubic inches
Mini est 18 x 22 x 33? = 13,068 cubic inches
Now only by accident 16/13 ~ 1.2373 or about 23.7% more volume than the Mini

Stumps XL Baby 18x21x33 = 13,167 probably little less due to sloped floor bout same as Mini

Made a ruler in paint shop n estimated XL Baby size/volume again. They gave nice info showing cook space down to bottom of last rack. Great guide for capacity estimating. Yall see the GetSmokin videos, he bought a Stumps Baby, good vids show close up details of doors, hinges etc stuff I'ld wanted to see better.

Took some time, deliberated, questioned, researched. Now I'll go finish it. Thank you all. Just hate to seem like I'm talking n not working on it. But that's how I already got that box done, something that now I feel like I have to use and not waste.

Have many of you used on average 1.5" insulation or are most using 2" insulation?

Some have said they like the Superior grease trap BETTER than Stumps. Forum Mini has 1" pipe with ball valve. Stumps has straight pipe emptying into a pan under cooker. Wonder does that let your smoke out, not good, leak? I thought just the pan would be fine if it could be held tight to prevent heat loss or unwanted airflow.

How is the Superior grease trap constructed? If Mini is kinda set n forget, after cooking some time with fatty meats, too much grease might collect in cooker (ball valve closed).......make a fire? Does eliminating the valve, just put a pan up tight under CC, sound good?

This is a about a Superior brand name GF Smoker Videos have same name as pic, mfr sent him another firebox. See how poorly made, they did not fully weld out the fire box. Such a critical part, thin metal and it warped.

I'm really interested in Superior grease trap. Glad we build the fire boxes better than mfr.

[LeonardK]

Size matters

Thing I really like most so far: spicy smokey baby back ribs --BBR, smokey chicken and a good cooked brisket.

BBR ranges 18 to 23 inches and I'll even leave the ugly ribs on the end too, once it's cooked they all seem to taste good.

I was thinking further how big's that brisket in the freezer, not as big as I thought, 9 x 18 inches long.

Just checking, size of what you like to cook could help decide size of smoker. Read about the ribs size thing last week.

12.53# Beef Brisket 9 x18 inches long.jpg

[Chromeski]

Stick to ribs and brisket, that cat doesn't have enough meat to be worth the hassle

[LeonardK]

What is the internal Cooking Chamber Height top to bottom???

I want to have as reference and may try to match that.

Average weight your mini comes to? About how much coal you burn at 220F for 10 hours or your average smoke?

Thank You

Leonard

[Chromeski]

I have not actually built mine yet. I'm gathering materials currently and using ready to start. I only have a couple free hours a week so everything takes me a while

[LeonardK]

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[LeonardK]

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