250 gal propane tank offset smoker build

  • Some of the links on this forum allow SMF, at no cost to you, to earn a small commission when you click through and make a purchase. Let me know if you have any questions about this.
SMF is reader-supported. When you buy through links on our site, we may earn an affiliate commission.
The green area is what you did the calculations for... Yes.... cut out the green area... When you figure out the area needed for the FB/CC area, add in the thickness of the CC and the thickness of the top plate on the FB... Cut out the end of the propane tank... cut PAST the welds for an easier fit up... slide the FB into the opening and weld the RF plate to the top of the FB... Cut out the opening to the FB.... Leave a small amount of metal for a dam to stop grease from flowing into the FB...



View attachment 451784

Grease dam for the FB....
View attachment 451786


FB/CC opening
View attachment 451787


Weld seam on a propane tank....
View attachment 451788

Adequate door opening for a smoker...
View attachment 451785


...

daveomak daveomak A picture is worth a thousand words. I see my error. I was thinking the FB/CC opening had to be oval in shape.

Seeing that, I know I did the calculations correctly .

My two tanks arrived safely yesterday. I was going to build a round firebox but it seemed like a lot more work for no real benefit. So, I am going to build rectangular fireboxes and build 2 smokers.

Here is another couple questions if you don't mind?

To seal the doors at the cut opening, I am planning on using 1" wide steel strips. I have heard of others doing this having to pound the strips to the right bend to conform to the door outline. I am wondering if I could take two long pieces of 1" steel strip and bolt it on both ends and tighten it around the perimeter of the tank like a clamp to make the proper bend?

Last question. I now have the CC/FB opening and the RF plate width. How do I calculate the length. My apologies if I missed it in the earlier posts or material you provided.

Thanks for all your advice. It has been invaluable. That circle calculator alone was a pot of gold.

JC :emoji_cat:
 
For the door seals, you can use 16 or 18 gauge steel... It's thin.... it can be easily bent to conform to the tank..... somewhere around 3/32 or even 1/16" steel... it's there to stop air.... and when the door is totally contoured, it is plenty strong to hold the door.... 1 1/4" width would be OK... You could drill or punch 5/16" holes every 3" to blind weld the seal to the door.. it will be plenty strong and it won't warp the door... start at the ends of the strip and tack toward the center of the strip... alternating the tack from end to end... letting the tacks cool will reduce warping of the door....

Plug and Slot welds.png


After the door is cut loose from the tank, check to see it is still the exact contour of the tank... if it was under tension, when rolled, it may spring back to it's original shape... NOW is the time to get it back into the proper contour....
Check the tank diameter , where the RF plate fits, to check the dimensions... Tanks aren't necessarily round and could spring back... Where the top of the FB fits, check the diameter... then measure up from the bottom of the tank to that same height and check the RF plate width... mark the RF plate placement the length of the CC, on the inside... check the width for the RF plate cut out... when installing the RF plate, and it is in place, tack weld to the FB and sides of the CC at the FB end... you can use a hydraulic jack and blocking to push down on the center of the RF plate at the END of the RF plate to put a slight bend in the plate and create a valley for fat to collect.... If the RF plate was the correct width, it will now be narrower at the far end and have a valley for grease, and slope about 1/2" away from the FB... TACK WELD the RF plate every 4" to hold it in place... a 1" skip weld tack.... that's all that's needed...

Does the above make sense ??? let me know where I need to clarify my thoughts... Sometimes I drift and proof reading doesn't catch it......

.
 
  • Like
Reactions: JC in GB
Build the FB 1-2" wider than the CC for ease in fit up.... Cut the tank past the weld seam by a couple inches for ease in fit up...

Slide the FB into the CC and tack weld it... THEN cut the FB CC opening with a torch... I use plasma... then you can weld it to the CC from the inside... Looks MOBETTA... 1" tacks will work...

Propane Tank weld joint INSIDE.jpg
 
  • Like
Reactions: JC in GB
REMEMBER to sit back in a lawn chair, with a beer or 2 and THINK and LOOK at, about what you are going to do... Will it fit... could I do this different... will it look good... should I read the directions 2 more times....
Mistakes are valuable learning experiences, BUT, they take time and can cost money.....
 
  • Like
Reactions: JC in GB
REMEMBER to sit back in a lawn chair, with a beer or 2 and THINK and LOOK at, about what you are going to do... Will it fit... could I do this different... will it look good... should I read the directions 2 more times....
Mistakes are valuable learning experiences, BUT, they take time and can cost money.....


Right you are on that. That is why I am taking so much time digesting what all this means. I want to know that I am doing the right thing before I do it. I don't want to waste time fixing mistakes that I made out of ignorance.

Once I get the whole design together in my head and can explain what and why of everything I am doing, I will be ready to strike an arc.

Don't worry about rambling, I read your posts at least 2 or three times until I understand what you are telling me.

Again, your help has been invaluable.

JC :emoji_cat:
 
  • Like
Reactions: daveomak
daveomak daveomak

This summer is just burning by. I am not even gong to be able to start cutting metal until fall.

I have been working on the manufacturing diagram for the smoker build and I still am a bit unclear as to how much area to leave at the RF plate end opposite the fire box.

This is what I have come up with for the RF tuning plate. Does this look right to you?

SMOKER 250_RF PLATE.jpg



JC :emoji_cat:
 

Attachments

  • SMOKER 250_RF PLATE.pdf
    44.4 KB · Views: 28
Hi ''JC in GB '' . I have just got back to reading posts on here and started reading your's because I to built a 250 gal smoker . Daveomak was a big help to me on my build. Just fallow the number's and you will be fine. Like Dave was saying earlier about the testimony to the calculated formula they have come up with. I build my smoke sole by dave's formula and now I have people that want me to build they a smoker. I use about 2 splits an hour to keep my smoker at Temp . If I done it right here is the link to my build. https://www.smokingmeatforums.com/t...the-bullte-250gal-smoker-on-a-trailer.254150/
 
  • Like
Reactions: JC in GB
Hi ''JC in GB '' . I have just got back to reading posts on here and started reading your's because I to built a 250 gal smoker . Daveomak was a big help to me on my build. Just fallow the number's and you will be fine. Like Dave was saying earlier about the testimony to the calculated formula they have come up with. I build my smoke sole by dave's formula and now I have people that want me to build they a smoker. I use about 2 splits an hour to keep my smoker at Temp . If I done it right here is the link to my build. https://www.smokingmeatforums.com/t...the-bullte-250gal-smoker-on-a-trailer.254150/

Thanks for the reply. Looking at your build gives me a lot more confidence that I have made all my calculations right.

A picture is always worth a thousand words. I don't doubt daveomak daveomak in the least. It is my lack of experience that has me second guessing everything I am doing.

Now that I see how your went together, I am even more anxious to get started on mine. I am going to have to wait for some cooler weather.

I was also kicking around the idea of one or two racks but seeing your build, it looks like I have plenty of room for 2 racks. Even better!

Thanks again...

JC :emoji_cat:
 
  • Like
Reactions: fire phil
I used the circle calculator and came up with this.....

View attachment 454915

What do you think ???


.

Matches my calculation as well. Well, I think I finally understand how this works now. Took long enough. :emoji_laughing: I am now confident that I can put this unit together right the first try.

Thanks so much for all your help. Can't wait to get cutting and welding....

JC :emoji_cat:
 
your welcome . and by the way you can see were I said that this was my first time ever building something at all. Loved the build "ALMOST" as much as I do cooking and eating off of it
 
  • Like
Reactions: JC in GB
My smoker can hold 30 Boston butts. 6 on each top rack and 9 on each the bottom . As for Temp. I have cooked 20lbs of chicken leg 1/4's for the guys at work and from start to finish counting worming the smoke up I only used 8 splits of wood. cooked for 2 1/2 HRs . looking forward to seeing Pic of your build.
 
  • Like
Reactions: JC in GB
SmokingMeatForums.com is reader supported and as an Amazon Associate, we may earn commissions from qualifying purchases.

Latest posts

Hot Threads

Clicky