Tanks do the same thing..... they are rolled then welded and the caps welded on....
It is fixable.... a little work.... but you want a very good smoker when you are done....
We really need to see a bunch of pics, as I said before, I think the problem is your draw which can be from your stack, air inlets, smallish firebox to chamber opening to name a few.
Have you tried running with your firebox door slightly open... does this help the draw?
Try extending the stack with a can or some flashing, just 8" or so and recheck.
this is just to show how a can fits, inside, extend your stack at the top of your stack not the bottom as I have pictured.
Take a pic of your firebox, are your inlets above or below the fire?
Make sure all your vents are open wide and there are no obstructions.
You can try bending the door by placing a bar or pipe in the door and closing the door on it, this worked for me, somewhat anyhow.
I would not worry about that gap but if you want you can silicone the door.
Wipe door with degreaser, and load up the door with high temp silicone (red).
Spray the smoke chamber that the silicone will butt up against with PAM spray, very heavy, if you decide to add clamps, add the clamps first.
note clamp on the right and left
The fact hat you have smoke pouring out of the smoke chamber and the inlets tells me its backing up somehow somewhere.
You should see the smoke come out of the stack at a pretty decent rate and the fire should suck in towards the smoke chamber.
When you open your smoke chamber door, the smoke should draw out from the firebox see pic below.
This pic is a bit extreme, a bunch of splits were added but it shows the smoke/heat getting through no problem. this tells me the draw is good to the point of the smoke chamber.
Now when I close the door I should see smoke exit the exhaust, if it comes out of the door, something is wrong (a little is fine), if it comes out of the inlets, something is definitely wrong.
Its usually more subtle like the pic below.
Hope this helps.
after rereading this thread then checking out your build thread, you can disregard a lot of this post but I will leave it as is, to potentially help others who may stumble upon this..
With that said I think the problem could be your inlet opening from the firebox to the cooking chamber.
It may be undersized. I hope I'm wrong
I'm judging this based on how low your firebox appears to be, maybe the other guys can corroborate this.
From your build thread everything looks good and it looked like everything was working fine?
Awesome build by the way
I think stack is a little short calculator says 36" it came out 30" above cc because of where I put my plenum.I can close the stack cover and watch smoke billow out intake holes but watch it suck back in as soon as I open stack back up.
Pretty sure that's normal, mine backs up out of the firebox and chokes the fire if I close my stack.