mp4 wrote:Heat is one factor - the other is the process of rolling the original barrel. It may have had to be squeezed together to weld it up from the factory and then springs open as soon as it is cut open.
This is what sprung my door out. While making the first cut along the top of the CC, there was a loud pop and the seam opened up a bit. I welded hinges across the cut (while the other 3 sides remain uncut) but the door still sprung out of round. That is, the curvature of the door did not match the curvature of the pipe. The pipe was made in Korea.
A 20 ton bottle jack and strategic blows with an 8 lb. sledge got it back into shape. The 2.5 ton jack curved the door some but just did not have enough muscle to bend the door all the way needed.
If you already have inside flanges installed, make sure that they are not interfering when you are re-fitting the door. A hammer works well on adjusting the inside flanges. Inside flanges are great for holding up the door while you are re-fitting it. Would have been extremely difficult to re-work the door without them.
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