No threat taken, I just want to make sure no one ends up hurt because of a misunderstanding in a post.
I would have to agree with you that having sparks inside of the drum could be very unsafe!
But the method I used allows no sparks to get to the inside of the drum at all. I think my definition may have been unclear and I'm not sure if I can explain it proper with out a picture during the grind process. Again I am not sure all drums are built this way, but the ones I have, are constructed in a manner that the lid starts out several inchs larger then the diameter of the drum. Unsure how they do this exact process but the lid is recessed down inside the drum about 1/2" then its rolled up and over the drum edge and down the outside so that the lid piece ends up with a hidden edge right near the drum side under the rim.
Where I grind is on the outside of the rolled portion of the lid material at a point where it in on the outside most point of the drum.
The reason I suggested this method was so that a person could reuse the lid as a lid for the smoker, I happened to use mine for an ash pan so I used the grinder to remove the rest of the rolled edge leaving a 1/2 lip.
I am curious about the pipe wrench method, sometimes I miss the obvious. Doesn't this method remove about 1" of material around the edge of the lid?
I in NO way want anyone to take my methods as a proper method or (the right way) to safely cut open any kind of pressure vessel or tank that has or does contain flammable product.
If any person that may read this is not 100% confident in there methods of cutting a tank, I suggest they take said tank to a qualified shop for the cut to be made.