My First Build - 120 Gallon on a trailer

Discussion in 'Reverse Flow' started by jasonlotz, Aug 19, 2015.

  1. Well I'm super pumped up to finally post an ongoing forum of something I'm going to build. I'm always so bad about documenting it so I'm gonna post a lot of pics so people can learn from all the mistakes I'm about to make.

    I'm using a vertical 120 gallon propane tank that will be a horizontal reverse flow offset smoker.

    I've already cut the door and built a 24" x 24" x 24" firebox.

    The tank has a 30" diameter and 48" length cooking chamber.

    Here's my first pic of it with the lid cut open and hinges welded on. I'll be mounting this permanently on a small Harbor Freight trailer that I've already purchased.

  2. smokejumper

    smokejumper Smoking Fanatic

    Hello jasonlotz

    You are off to a great start. That is an ideal size tank for a RF smoker.

    Looking forward to more pics of your build.

    You might want to rethink your hinges...

    Having the pivot point so close to the seam makes it really difficult to put a sealing flange along the top of the door.
  3. hardcookin

    hardcookin Master of the Pit

    Looking forward to following your build.
  4. is2326

    is2326 Fire Starter

    Congrats on the start of your build. Looking forward to seeing more. What is the width of your door? Your tank looks just like the one i'm doing right now. My tank is 30'' dia and 30'' from weld to weld.
  5. So my tank is 29" inside diameter. My door width is 32" right now, I cut it on the last flat parts before it curves on the dome ends. I did cut it all and left a little bit on each side, then welded my hinges on and then finished cutting it so the door wouldn't spring out of shape, that worked well and the door stayed true. I'm going to be welding on a counterweight to offset the weight of the door because I cut the top seam dead center in the tank, in hindsight I didn't have to go that high I guess BUT I have a cam shaft from a detroit diesel I'm using as the counterweight that will look cool. Also using a chrome 5" semi smoke stack and then grab handle from a semi as my door handle and firebox door handle.

    Last night I finished cutting the firebox opening and did a dry fit of the firebox into the opening. Everything fit up nicely with minimal grinding needed.

    Tonight I'm going to weld the two together and then mount it on a small Harbor Freight trailer I bought for $170.

    Last edited: Aug 21, 2015
  7. dukeburger

    dukeburger Master of the Pit OTBS Member

    Liking where this is headed! [​IMG]
  8. jcbigler

    jcbigler Smoking Fanatic SMF Premier Member

    Yeah buddy, looking nice!
  9. Well this weekend I hit it pretty hard. I'll add some more pics tonight but I have it all welded up to the trailer now. finished my lip around the door and the firebox sides and grate. Also built the reverse flow plate and a piece of angle iron down the middle with a 1" pipe through the bottom from that plate as a drain where I'll have a ball valve on the bottom.

    I'll take more pics tonight and then I can work on the firebox door, my cooking grates and my smokestack. Can't wait to cook on this thing.

  10. is2326

    is2326 Fire Starter

    Looking good.
  11. So I have the firebox all ready now, just need to build the door


    The reverse flow plate is nearly complete, one piece to weld in yet.

    I was all good up to this point. I welded on my arms for the counterweight. Problem is I'm not sure if I like how this looks. I love the freightliner smokestack I have and want that to be more of a focal point in the design. I have a camshaft I was going to mount on as the counterweight which looks cool and we attached last night and it worked awesome. I'm just not sure if I like how it looks. What are my other options?

    Just wondering what ideas people have for options out there. I could use a pulley system with a few pulleys on the sides and have the camshaft hanging on the back side as a counterweight. Could I use something like hinges from a car hood with the coils in them to help as a lift assist?

    Maybe I'm overthinking it and this looks just fine. Input welcome.
    Last edited: Aug 25, 2015
  12. is2326

    is2326 Fire Starter

  13. Yes on the bottom part of it I'm still need to cut an angle to it, it also needs to be up a little higher in the cooking chamber I think but not much.

    I'm really struggling with how to make it look good with the counterweight though. Any thoughts on car hinges welded on the inside that have the round coils to assist the lift at all?
  14. is2326

    is2326 Fire Starter

  15. is2326

    is2326 Fire Starter

    Here is the style I used and I don't need a counter wait or prop. I simply open the door to about 90* and like magic it stays open and I love it. Nice and clean. 
  16. THat is a cool hinge design, so does the hinge part on the door slide in that channel then and just bind to stay open? I'm a little perplexed on how that works exactly but looks awesome!
  17. is2326

    is2326 Fire Starter

    I studied many styles and went with it and I love it. As you can see it these pics I can leave the door open with nothing to support it. 
  18. THat's awesome! that is the exact size of my tank I believe. I'm still thinking about how I'll do the door, I have my hinges welded on REALLY good already but could grind them off and use something like this eventually. Is the door heavy to open, mine is a bear to lift, 1/4" steel on my tank walls.

    You did a helluva job cleaning that thing up, I'm going to sandblast mine later this week, did you use a flap disk and polish it or how did you achieve that shine?
  19. is2326

    is2326 Fire Starter

    I'm guessing the door may wait around 30-35lbs 1/4 steel. Opens easy and smooth the best part I don't have to add counter weight or any clutter... When I got the tank it was painted white so being cheap for (sand blasting) I bought stripper and with a little elbow grease it came really easy. Then I used a flap disk and 60 grit sand paper. The sand paper makes it shine, Not what I was going for thought an all chrome smoker might look cool... Na.
  20. Well I decided to stay with my original counterweight, after mocking it up last night I liked the look of the camshaft from that Detroit Diesel hanging up there. That with the semi smoke stacks just look cool and the door opens really nice, it balances perfectly at the half way point and makes a great stop too.

    I also finished up the first rack and the slide rails for the top one. I'm going to have a middle rack as well with 2 slides so I can adjust the height on that one in case I have larger pieces to put on the bottom rack I can move the middle one up a few inches.

    Tonight I should able to finish the racks and then I just have the firebox door and weld in the smoke stack.

    Does anybody have a suggestion on the depth to have the smokestack inside the cooking chamber? I'm thinking where I have it should be ok, I'm going to cut a 45 degree angle on the bottom and the furthest point down with be about 5" above my bottom rack, about half way in the cooking chamber.

    Last edited: Aug 28, 2015

Share This Page