I always giggle at the names of the tinsmith and coppersmith machines, which were designed in the very early years of the 1800s. They just simply did not get very creative with names, and let each machine keep it’s very literal name. Hence a burring machine will create a burr. A wiring machine will wire. A turning machine turns metal. You get the picture.
And, like it’s name, a setting down machine sets down seams.
However, before that can happen at all, there’s a few steps that must be done first. You first must create a crimp seam by using the burring machine. On the bottom of a body, you’ll create a 90-degree burr, which hopefully you’ve accounted for in your pattern cutting (usually this burr is 1/8” or, at most 3/16”).
Then, you’ll take your bottom piece, which is circular, and once again a burr is accounted for in the measurements and raise another 90-degree burr that’s also usually 1/8” or 3/16” to match the body’s burr.
After this, you now need to fit the body burr inside the bottom burr. They should fit together very well, almost too tightly, but never loose. If the body is too big to fit, you can carefully shave off some material with a snips. If the bottom is too big, you’ll want to hammer out the burr with a rawhide hammer, and re-set the burring machine to create a bigger burr and then try fitting again.
Once you have the body and base fit, you’ll take a setting down hammer and lightly tap down the crimp seam while pressing down on the body from the top to make sure the piece is sitting flat – essentially wrapping the base burr on top of the body burr. Be careful not to damage the body with errant hammer strokes.
When the seam is mostly set, now you finally can use that setting down machine. It will create a uniform and smooth looking crimp seam (and pave the way for a double seam if that’s your desire) and you can solder it – voila! A waterproof, set seam!