2013-11-12

Small but tall bronze pots

I have spent the past few weeks making various bronze pots with between four and six sides each, out of silicon bronze except one of the two square ones which is phosphor bronze (7% tin). All are in thick metal, 16 gauge (about 1.63mm) supplied by Columbia Metals Ltd. In all cases I milled the required number of parallel grooves for the fold lines of the initial rectangular sheet of metal; this was fairly straightforward for the square-footprint pots since I have a 90° Proxxon milling cutter. I found by accident that this works pretty well for the two five-sided pots although the grooves do not close up as much as one would like when the metal is folded. However for the six-sided pots I had to mill each groove somewhat more than half-way down using the 90° cutter, then manually cut the remaining groove using a 60° grooving chisel down to the required depth (i.e. until the metal showed a plain line on the reverse). I calculated the depth required using simple geometry. All pots were soldered using hard silver solder for the grooves, and usually medium or soft for the base / top.
The first picture shows an array of the pots in various stages of finishing, fitting of lid bezels etc.
The second picture shows one of the square pots before the faces had been sanded to remove surplus solder.
The third picture shows one of the square boxes, wired up, horizontal on fireproof bricks, just after soldering one of the grooves. I would then rotate the pot while red hot with stainless steel tongs and solder the next groove.
The fourth picture shows one of the square pots wired up ready for soldering of the grooves.

Six bronze boxes Pentagonal bronze box Square tall bronze box Square tall bronze box

The last picture is of a rectangular sheet of bronze, scored for folding into a square 4-sided pot, showing that in fact it could easily make a pentagon.

Bronze with 3 scored grooves

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