Preventing Door Spring Back on 20" diameter 1/4" wall pipe

Discussion in 'UDS Builds' started by mrsmoklestein, Aug 1, 2016.

  1. mrsmoklestein

    mrsmoklestein Fire Starter

    I have a 20" diameter x 40" long piece of pipe that I had rolled from 1/4" thick cold rolled steel and tacked into place. I have completed the bead on the inside and out of it. Now, before I weld on the end caps I am debating if I should add some crescent shaped bracing pieces to the inside of the cook chamber door to prevent spring back when it is cut loose.

    Sound like a good idea or not? I know most guys don't do this, but then again a lot of guys are cutting into propane tanks and can't weld anything from the inside.


  2. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Maybe the idiot commercial fisherman has some ideas....   Nah.... you wouldn't listen....  He's not in the mood for any more disparaging remarks either....
  3. mrsmoklestein

    mrsmoklestein Fire Starter

    Yeah, you're a commercial fisherman )....and I'm a tool and die maker. So OF COURSE I'm going to question your metal working information and ask how you're coming up with it-as I'm sure you would be doing if I was giving you advice as to how to fish steelhead....and I believe I ASKED you very nicely and TRIED to get more information out of you. Once again, I have more than a few bucks tied up in the build and regularly deal with very tight tolerances when it comes to metal-so YES I will talk your ear off about it.

    ...but I'm not going to continuously apologize (and I have done so several times) to you and kiss your @$$ in order to gain information, so if that's what you're looking for-I'm not your man. 
    Last edited: Aug 2, 2016
  4. ahumadora

    ahumadora Smoking Fanatic

    I cut 500mm and 600mm  3/16 and 1/4" quite often.

    Cut some steel rods the exact internal diameter first then get a new tip on the plasma and buzz through it fast.

    Knock the rods into the end of the tube, make sure it is perfectly round and weld in your guides.

    After the guides are welding in make sure to weld on the anti tip tabs BEFORE you weld the end caps on.

    Tig weld the flange on the door with short welds every 150mm, put on the tube and weld on the hinges.

    If it has warped put it off and give it some love with a sledge hammer or bottle jack and chain.

    On the propane tanks I cut the doors and weld in the guides before doing the firebox to stop the tank distorting.
    Last edited: Aug 5, 2016
    mrsmoklestein likes this.
  5. mrsmoklestein

    mrsmoklestein Fire Starter

    Thanks for the reply. It sounds like you tack on braces to the entire inside diameter of the cook chamber-and the problem with that for me is that I had the cook chamber pipe rolled at a machine shop so it's not perfectly circular. I am also without a plasma cutter What I had in mind was something like this....

    Do you think that's a good idea?....or does the whole piece of pipe need bracing? I was going to tack the gusset (brace) pieces in place, then complete my hinges and flange pieces. I was hoping that once the smoker saw some heat from a few cooks, they could be removed eventually. 
    Last edited: Aug 5, 2016
  6. ahumadora

    ahumadora Smoking Fanatic

    1./ Your door gusset idea won't work. When you try to close the door it will hit the grates.

    2./ I don't weld braces on anything.  The steel rod is just a 3/4" bar I hammer into place and the whole tube conforms. I then weld in the guides and it doesn't move after that. I remove the rod after I have welded in the guides.

    3./ Use a 9" grinder with a 1/8" cutting disc to cut the doors. (Watch out they are nasty S.O.B's) but get the job done fast and clean.

    4./ Make sure the weld seam is at 6 o'clock and take all your measurements from there. ( wrap a tape around the outside and divide in 1/2 ,1/4 to get your 12 o'clock and 3 o'clock).

    5./ On a 20" tube I make the door cut at 75mm (3")  past 12   and 3" below the 3 o'clock for maximum clearance and can get 2 grates in there , no problem.

    6./Cut a compressor tank that is 40 years old and they will spring. cooking on it won't change anything.

    7./ If you get your end plates plasma cut they will be perfectly round. Cut them to halfway between the ID and OD to give you a nice groove to weld. Stand the tube on it's end when doing this.   MAKE SURE you have welded on your tabs to stop the grates tipping as you can't get the welder in there after the end plates are on.

    8./ I would mount the door BEFORE welding the end plates on so if it is out of shape you can make the tube conform.
    Last edited: Aug 5, 2016
  7. mrsmoklestein

    mrsmoklestein Fire Starter

    I don't plan on having double grates in mine, I think this is where the collision you're talking about would occur with the gussets. They are shorter that the vertical distance of the door.

    What tabs are you talking about to stop the grates from tipping?

    Thank you
    Last edited: Aug 8, 2016
  8. ahumadora

    ahumadora Smoking Fanatic

    If you have cut gussetts out already and only running one grate then weld em in.

    if you look nearly every pit smoker has tabs welded onto the guides so you can pull the grates out over halfway without tipping.

    Most of the time it is another bit of angle welded to the back of the guide.   look at the photo below.  Weld these tabs on BEFORE you weld the end caps of the tube on or you can't get a weld torch in there.

  9. mrsmoklestein

    mrsmoklestein Fire Starter

    Gotcha, now I know what you're saying. My grate will sit on two pieces of 3/4 angle iron welded parallel to the length of the cook chamber (the long way)-so I'm doing things a bit differently and do not have to worry about tabs.

    Thank you for the feedback though!

Share This Page