120 gallon r.f. smoker beginning.

[Alexb.]

greetings, getting started on a 120 gallon propane tank r.f. smoker/bbq. trying to find all the posts with that size tank. any direction is appreciated. i did find the calculator so thats a good start. will post pics when i figure that out.
thank you all in advance.

here is calc. dimensions.
Link to BBQ Pit Calculator
firebox will either be other used tanks, part of one of these, or make square and have a warmer box on top of the square if i go that route.
here is photo of tank{s} , yes 2 free ones but only making one for now. i have multiple options for firebox material
http://s465.photobucket.com/user/alexinjt1/media/4c4ff2fb-ac7b-49d7-8766-663afc4c1406_zpsw8l5qglx.jpg.html?o=0[/img]

[k.a.m.]

Welcome to the ring Alexb., looking forward to seeing some pics of your cooks and following your cooker project.
Congrats on the tanks nice score.
I would go wit the square firebox I would also increase the exhaust diameter to 5" or 6". The 3" will cause you issues.
_________________
Always remember slow and steady wins the race.

Hybrid Cooker

[Alexb.]

[k.a.m.]

A 3" exhaust at 67" long will cause the heat/smoke to stall in the pipe creating cold smoke in the chamber.
If your cooking chamber is 24" in diameter and your lower grate is cut at 3:00 and around 37" off the ground that puts the top of a 24" exhaust between 61" and 81" depending on placement.
Even a 4" ID exhaust at 36" would be better than your 3" at 67".
An offset cooker has to breathe. My newest build is a 24" x 55" chamber I am running a 6" x 24" exhaust on it.
http://thesmokering.com/forum/viewtopic.php?t=67710&start=160
_________________
Always remember slow and steady wins the race.

Hybrid Cooker

[Alexb.]

thanks for directing me to your new 120 gallon cooker, i will get allot from it im sure.
i "THINK" i want a hybrid like your giant trailer set up because once or twice a year i may do a whole hog{do them in block pits now for church or get togethers} but mostly for multiple cuts at a time for family, couple times a year for church events of 100 or less. so the r.f. for the whole hogs slow cook///and the direct flow for other times with tune plates...
question-why did you make this new cooker "just" direct flow and not r.f. also? that might help me decide for mine too.

also i found plenty 6inch pipe in pile for exhaust so i will use that instead of 3 inch.
i have 1/4 plate for tune plates but i also have 3/8x6" plate i could use if that extra 1/8 inch thickness not a problem.

[k.a.m.]

My Hybrid never leaves the tuning plate set up I built her the way I did mainly to have options if the need arose. I have cooked in the reverse flow set up but I prefer my plates. My new cooker is pretty much set up for my competition needs with only three grates. I can use it for other things to be sure of but my whole thought process on this one was for competition cooking.
I prefer square fireboxes because the size can be manipulated to fit the cookers needs. The problem with pipe fireboxes is you are stuck with diameter and length. Too small a diameter and you have to compensate for length but you still have no room for a coal grate and lower air under your coals.

Besides weight the 3/8" plate will work for your plates, the 1/4" is all you really need.
_________________
Always remember slow and steady wins the race.

Hybrid Cooker

[Alexb.]

glad ur here right now kam. im heading out to cut doors. im guessing at 12 and 3 oclock, yes?

[Alexb.]

maybe i should slow down a minute.....should this be my plan----1-cut doors, and add legs to hold to height.
---2-make square firebox and door with intakes.
----3---cut firebox to chamber hole and fab in,
------4--add firebox to chamber
--------5--angle deflection plate {what angle?}between firebox and chamber
----------6- add tune plate rails,
------------7-add drain {im guessing for grease?}
--------------8--add tray rails;
----------------9- add chamber exhaust.
------------------10- add misc. couplings for temp gauges on doors and handles on doors. also custom couplings for digital temp. wires to run inside chamber during cook.
--------------------11- hinge doors to chamber.
-----------------------12- fab trays for chamber and firebox.
then add on stuff as i find it, but does this sound about right?

[Alexb.]

[quote="k.a.m."]My Hybrid never leaves the tuning plate set up I built her the way I did mainly to have options if the need arose. I have cooked in the reverse flow set up but I prefer my plates.

so with tune plates and exhaust only open on opposite side of firebox has worked for long whole hog cooks?
if so i may just go this route also.

another question---if i leave the center strap between doors like yours, what do you think about hinging the end off tank opposite the firebox to be able to slide out the tray with whole hog on it? so 3 doors total-2 in normal position like your new build plus and "endcap" door? just a thought as i type. or just hinge the strap like your friend mentioned in your post.
or just one larger door seems the easiest way, yes?

[k.a.m.]

Your plan seems about right for building the cooker.
On the deflector if needed I prefer not to angle it more than 25° if I can get the distance I want with in that I am good.
The cooker will cook a hog fine with tuning plates.

You can add the door on the end I have seen several cookers with that set up. I have also seen them with a hinged center strap but I do not really care for that. Another option is flat doors and no center bar at all.
_________________
Always remember slow and steady wins the race.

Hybrid Cooker

[BurnBern]

[Alexb.]

http://s465.photobucket.com/user/alexinjt1/media/0201161542_zpsfvmxqfqj.jpg.html

thinking i will cut out all these bungs and fill flush, and then turn tank over/upside down for rest of fab...so that all the extra welding the bungs in wont effect the door cut out more then already will.

[Alexb.]

Now I don't have experience in building smokers as I'm busy with my first build. But in all my readings and a lot of peeps seem to recommend a grease dam about 1 1/2" high to prevent a grease fire at the FB end. Looking forward to following your build. Bern[/quote]

thanks, good catch. will do.
got the needed material this afternoon, started cutting the firebox plate....bummed out i have to work a couple hours 2maro for gate install...then back to fun.

[Maniac]

Alexb. Welcome to the ring
good luck with your build the tanks should serve you well.
_________________
RF Smoker
20" disc
uds

[Alexb.]

here are my revised calcs.
Link to BBQ Pit Calculator

but i think i will make the 6 inch exhaust 24 long to get it at least 6 feet tall, hope that wont mess it up, can always cut some off if it does. or longer legs to get bottom of door/bottom grate @ 42" above ground, that could work too.

[k.a.m.]

Set your cooker grate height to any height that you are comfortable with. I reference 37" because that is the average height of a stove top. If 42" works better for you then place your gates ate that height.
I do not see a problem using 24" of 6" for the exhaust.
I hope this helps.
_________________
Always remember slow and steady wins the race.

Hybrid Cooker

[wango]

Welcome to the Ring Alex! Good luck with your project.

[Alexb.]

greetings,
welded the firebox up and started on door.
i made it 24x24x24", larger then last post "revised calc's", hope that didnt screw me. here is the new calc's.
Link to BBQ Pit Calculator

its 149% of whats needed, if anyone thinks i created a huge problem i can cut and move back wall in to get closer to the 100% needed. i did notice when i put the new firebox dimensions into the calc., it elongated the exhaust from 16 to 24 inches, so maybe that makes it o.k. and for usable temps in the cook chamber.

also, i am covering the door cut out kerf { about 1\16th from plasma torch} with a 1 1\2x1 1\2x1\4" angle frame on outside,welded to door to help stabilize warp and seal the kerf, covering each side of kerf about 3\4". but im thinking i should still use some of that 1\2" wide x 1\8th" self adhesive backing to get a very tight seal if it needs to be that critical. but it seams that if the slider covers for the air inlet t the firebox isnt that perfect seal when closed it might not have to be that critical. also i am skeptical the self adhesive wont fail from the heat of the firebox.

or maybe im just paranoid about all this and should "just weld it" as an old boss used to yell at me. and then id cut it apart to do it the right way. hmmm.

next- the tag on this tank said it was made 1944, thought that was cool. it had 7 fittings on top i had to cut out and fill in 2" diameter plugs, and they are all at 12 o'clock relative to the existing feet on it. plus the two horizontal welds for the 2 sections { this had 2 bell ends, and 2 half's for the cylinder shape welded at 3 and 9 with a huge cap weld, so 4 peace tank}. so my thought is to rotate the tanks existing 12 back to 11 oclock and that would put those 7 "plugs" about 9 inches away from the top of door, and maybe that will help prevent some warping from the "pull" from those plug welds. this also puts that huge cap and seam weld at about 2 oclock and keeps that away from the bottom of the door cut, hopefully preventing some of that "spring/warp".
here is photo before 'plugging" .http://s465.photobucket.com/user/alexinjt1/media/0201161542_zpsfvmxqfqj.jpg.html?o=0
anyway, thanks for the help.

[Alexb.]

and thanks fella's for the 'welcome to the forum".
i appreciate every ones time and help, and humor.

[k.a.m.]