• 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.

250 REVERSE FLOW W/ TRAILER BUILD

j-rod

Fire Starter
56
10
Joined Jan 14, 2008
I finally decided to try my first smoker build.  I have been working on this project since Christmas, and needless to say, it was a bigger job than I thought it would be.  For all of you who have tackled this type of project, you have my respect.  For all of you who have tackled this type of project, and taken pictures, and posted informative threads, and answered questions, you have my sincere appreciation.  I definitely could not have done this without your help.

My grandfather started a well drilling business in 1954.  Luckily for me, his early rigs ran off propane.  We have had a 250 gallon propane tank mounted on a trailer stuck in the weeds behind our office for at least 30 years.  The tank had a stamped aluminum tag that put the date of manufacture at 1963.  The wheels/tires were destroyed by weather and time.  I had to find new wheels/tires before I could easily move the tank.  I am also going to need to rework the tongue.  I have had the intention of converting this rusting relic into a smoker for several years but haven't had the time.  With the economy in the condition it is in I found plenty of free time this winter.

 



This build was actually completed this past weekend and I am going to attempt to show the build from start to finish but I didn't take near as many pictures as I wanted to.  Thanks again for all your help.  Most ideas for this build came from this very forum!!
 

j-rod

Fire Starter
56
10
Joined Jan 14, 2008
Used the BBQ pit calculator to give me firebox info.  Build firebox out of 1/4" plate and 1" square tubing.  Really wanted to double wall/insulate the firebox but the weight would have been crazy.  The firebox alone ended up weighing over 400 lbs.  I imagine it would have been 800 or more if it was insulated. 





More to come
 

SmokinAl

SMF Hall of Fame Pitmaster
Staff member
Moderator
OTBS Member
★ Lifetime Premier ★
48,024
8,464
Joined Jun 22, 2009
Looking forward to seeing those final pics!
 

ledhead84

Smoke Blower
85
10
Joined Feb 9, 2011
Looking forward to seeing the progression. i think we need a teaser of the final product.
 

cowgirl

Legendary Pitmaster
OTBS Member
7,642
46
Joined Oct 2, 2007
I'm looking forward to seeing your progress too JRod. Home builts are my favorite.  
 

j-rod

Fire Starter
56
10
Joined Jan 14, 2008
The tongue needed some TLC. I removed the old and added a new hitch and jack. I wish I had a longer piece of tubing to extend the length of the tongue and make the trailer easier to back but this is all I could find in scrap.





Next I removed all the extra "junk" off the tank (I want the final product to be nice and smooth) and marked the location of doors and firebox. I also had to move the axle back as far a possible to try and compensate for the additional weight of the firebox. The trailer was balanced perfectly before and I knew when I attached the firebox it would flip up.





More to come. . .
 

j-rod

Fire Starter
56
10
Joined Jan 14, 2008
I definitely forgot to bring the camera with me for a couple of weeks. I could have sworn I got some pictures of the finished firebox before it was mounted but I can't find them. Oh well, there should be enough details in the rest of the pictures. At this point I have mounted the firebox, cut out the doors, added banding to outside edge of doors, bent and welded on door handles, and started the reverse-flow baffle.









A couple of things that will make your life easier:
#1: Listen to these guys when they say to attach your hinges before you cut out the doors. (I attached my hinges to banding not straight to the door)
#2: Cut the top of the doors and the bottom of the doors (including the corners). This will leave a few inches of uncut metal on the sides of the doors. You can then attach your banding to the bottom and top of the door and attach hinges before you finish cutting it out. This will keep the door from swinging in when the cuts are complete.
#3: Do not attempt to cut your tank at the factory weld(vertical weld near the ends of the tank). I decided to cut my tank vertically, along the inside seam of the factory weld. Figured I could get a nice straight cut this way without having to take time and mark it. Turns out the cylinder and cap (parts that compose the tank) are overlapped where they are welded. So instead of having to cut 1/4" thick steel I ended up having to cut 1/2" of steel. Needless to say, it was time consuming.
#4: I purchased and attempted to use a metal cutting saw w/ blade to cut out the doors (spent about 350.00 bucks). Saw worked great on metal thinner than 1/4", worked ok on flat plate no thicker than 1/4" (wore out first blade very fast), didn't suite me for work on the curved tank. Ended up using cut-off wheels on a side grinder for doors and firebox opening.
 

j-rod

Fire Starter
56
10
Joined Jan 14, 2008
Next I worked on counterweights for the doors. This was one of the most frustrating parts of the build The doors weren't extremely heavy to begin with but I wanted something that would hold them open when I need to be inside. I also wanted to be able to reach the handle to pull down the door when I was ready to close. When I was trying to figure this out I decided that I wanted my counterweight to be just inside my hinges when the door is closed. I figured this way the weights would actually help the doors to stay closed when going down the road but if you opened the doors a couple of inches the weight would start to pivot behind the hinges and aid in opening. Either I was lucky or right because this seemed to work great.



Used 3/16" steels for the sides and some scrap 3-1/2" pipe for the bulk of the weight. I decided on the width, that I wanted the weight, and cut pipe for both sides. I then cut a couple of 2x4 to hold open both doors at the same height (where I wanted the doors to stop when completely open). I really just guessed at the distance I wanted the weight from the door and used some scrap 1" tubing to tack it to the door while it was resting against the tank (with door in the open position). I then gently closed the door and checked out weight location. I tacked the weight in such a way as to be able to make adjustments to the weight location. After much head scratching and cursing I got both weights located in, what I felt, was the perfect location. I then used cardboard to make a template of the 3/16" end plates. After they were cut out I found some old 1/2" rebar and cut several pieces to a length that would fit inside the weight. I welded on one side of the 3/16" end plate and started adding rebar, opening and closing the door to find the perfect weight (I think it took 11 pieces per door). When I got the doors weighted right I welded the rebar in place inside the pipe, welded on the remaining end plate on both sides, and removed the scrap 1" tubing that was holding everything temporarily in place.





It wasn't exactly easy but I couldn't think of an easier way to do it with the tools/materials I had to work with.
 

diesel

Smoking Fanatic
594
28
Joined Apr 29, 2008
Man, that is one fine looking smoke machine!  I have been cooking on a RF for about a year now and it is amazing how well it cooks.  Good job!
 

Dutch

Smoking Guru
Staff member
Administrator
OTBS Member
SMF Premier Member
OTBS Admin
Group Lead
7,106
406
Joined Jul 7, 2005
J-Rod-my son saw the size of your firebox and said "Dang-he could cook breakfast or hamburgers on the top of that fire box!" Great build you got going!
 

SmokinAl

SMF Hall of Fame Pitmaster
Staff member
Moderator
OTBS Member
★ Lifetime Premier ★
48,024
8,464
Joined Jun 22, 2009
Not much to add other than WOW!
 

j-rod

Fire Starter
56
10
Joined Jan 14, 2008
Dutch you are absolutely correct. I didn't have a great deal of height because the trailer is so low to the ground so I made the firebox wider and deeper. I definitely wanted to make sure this baby could heat up!

I wanted to show a couple of picture that I got of the finished baffle and describe what is going on for anyone wondering about reverse flow. The pictures I have posted so far only show a partially completed baffle that has been tacked. When completed the baffle runs from the firebox end of the smoker to within approx 6" of the opposite end and is solid from front to back (the 6" area is roughly the same square inches as my firebox to smoker opening and my exhaust capacity) I will try to include a pic that will better explain. This picture is looking at the far end of the smoker (away from the firebox). The baffle ends 6" before the end of the tank and has a 1-1/2" pipe welded to the bottom of the angle (running down the center). This allows all grease to run to the channel and exit the smoker. The baffle is sloped towards the center (toward the angle) and runs downhill (towards the 1-1/2" drain) to help the grease run. The angle you see above the baffle is just rails for the cooking grates so don't let that confuse you.



Here is another picture. Once again looking from the firebox end towards the drain.



I didn't get a picture looking back towards the firebox but the baffle just runs all the way to the end of the tank. The rounded shape of the tank can make it tricky to get this cut and welded but I used a piece of cardboard to mark the shape of the end of the tank (once I had notched out the location of the firebox but before I welded the firebox in place). Then I used the template to mark the curvature I needed on the baffle plate. Most people just run their baffle off the end of the firebox so there is not need to cut out this shape but I figured that I might get a more even temp if there was an air gap between the baffle and the firebox instead of the top of my firebox being part of the baffle. Hope that made sense, don't know if it made a hill of beans but it made sense to me that it might cut down on excessive radiant heat on that end of the tank. I placed the actual baffle about 2"-3" above the firebox. Hope that helps, sounds as clear as mud now that I am re-reading it.
 

j-rod

Fire Starter
56
10
Joined Jan 14, 2008
Next came the stack. Since we are a well drilling business it was easy to come up with steel casing to use. I cut about 32" of 6-5/8" OD steel casing and welded it in place at the firebox end of the tank. I wanted two things on this stack. One is the ability to choke back the exhaust in case this is ever needed in the future. The second is the ability to keep rain out of the stack when it isn't in use. I didn't want to do this with an internal damper and a cap so I found some pictures of another build that adressed these options with one component (sorry I can't remember who to give credit for this but it wasn't my idea).



I took a scrap piece of 1/4" plate and cut it out using the casing as a template. I smoothed it down with a belt sander and welded on 1/2" rod to run down the casing and act as a handle to open and close it. This way I can open or close the lid to dampen the exhaust if needed and close completely to keep out the weather. Very happy with the way this turned out.
 

j-rod

Fire Starter
56
10
Joined Jan 14, 2008
Next I welded on some new fenders and added a shelf under the doors. My original plans were to have this shelf fold out of the way when not in use but the axle is so wide this seemed like a lot of trouble for nothing. Since the tires are wider than the shelf, I made it permanent, and it turned out very solid. I also built a table over the firebox that will swing IN when on the road and swing OUT when it is in use. Took me two attempts on this to get it the way I wanted it but I am pleased with the way it turned out and it added a lot of table space. (another borrowed idea)









Also got the gauges in place.
 

atcnick

Smoking Fanatic
381
40
Joined Jan 1, 2010
Man thats awesome!  You guys that built smokers make it look so easy.  I wish I had a clue how to weld and work with metal.   I've looked at a few of these built threads and one thing I havent seen is how much money people have invested in the smokers?  Im curious how much you save by building your own???
 

fourashleys

Smoking Fanatic
412
10
Joined Jun 28, 2010
[quote name="atcnick" url="/forum/thread/104189/250-reverse-flow-w-trailer-build#post_617267"]
Man thats awesome!  You guys that built smokers make it look so easy.  I wish I had a clue how to weld and work with metal.   I've looked at a few of these built threads and one thing I havent seen is how much money people have invested in the smokers?  Im curious how much you save by building your own???
[/quote]

I came in just under $1000 on my build. Definitly saves on the wallet. More cash for the butcher.:biggrin:

Great job on your build!! Nice looking rig ya got there! Now it Q time, enjoy it.:th_wsmsmile0ly:
 

Hot Threads

Top Bottom
  AdBlock Detected

We noticed that you're using an ad-blocker, which could block some critical website features. For the best possible site experience please take a moment to disable your AdBlocker.