To cut the firebox, you can see in the 2nd picture in post #16 at the bottom of the tank where I marked the firebox with a black sharpie. I only cut the back of the firebox. The top of the firebox remains intact and becomes part of the reverse flow plate/water pan. You can also see in picture #1 of post #16 that the back of the firebox is not welded to the top of the firebox. (Only 2 little tack welds) This is because I knew I would be cutting the back off and didn't want to have to cut the weld seam there.Boomhower, I have a question.... the firebox to tank cutout...... It looks like the cutout fits perfect inside the radius of the tank end..... How did you know where to cut the firebox to match the two different radii in the end of the tank ??? I'm going to assume a compass scribe technique was used.... Anyway, it looks perfect to me.....
I need to learn something today and you are my "go-to-guy" at the moment.... Dave
The hard part was actually before that. Laying out the lines on the curved end of the tank (smoke chamber). That was tricky.
For that,I first used a framing square (too get the horizontal line of the cut when looking at the end of the tank (smoke chamber). With the tank sitting flat on its casters on the (somewhat) level concrete floor,I marked the height of the cut and then used the framing square sitting on the concrete and marked the line around the curve of the tank in several places. Then I connected the dots.
For the vertical portion of the cut, I simply measured from the weld seam (the welded seam of the main cylindrical shell of the tank to the formed "domes" on the end) to a point 2" (I think) up on the radius and marked it in several locations around the tank. Then connect the dots for that line.
It wasn't perfect with the first cut, but once I had the main cut, I test fitted the firebox and marked where it needed more material removed on the tank. Then grind the high areas down until you have a good fit.
I'm sure there's easier ways to do it, but that's what I did.
I also "cheated" and had drawn it up in CAD so that I got the area for the firebox to smoke chamber connection correct (according the the smoker calculator I found on this site somewhere).
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