I’m making bangle bracelets from copper, and didn’t care for the solder seam from just cutting a strip, bending it round and soldering the ends. So I decided to try to form them from sheet using a hammer & mandrel. I cut a piece of sheet that looks roughly like a 45-rpm record (anybody here old enough to remember those?), slip it over my tapered mandrel and hammer/anneal/hammer/anneal/hammer until I get a mostly-straight-sided bracelet-sized cylinder.
Here’s my problem: I’m having trouble figuring out how to get that last bit of the edge – the one that was formerly the outside edge of the disk – hammered down to match the size of the edge that started out as the inside circle. Does that make sense? That last bit of flare. I can’t figure out how to get rid of it. Hammering against the mandrel doesn’t work. It just shifts the metal around.
I think I need something to confine the metal while I hammer. I’m thinking something like an inverse mandrel. Like a big, really stout funnel I can hammer the wide side of the bracelet down into.
Does anyone have any ideas? My tools are limited. No stakes, no hydraulic press. I’m willing to acquire the right tools, if they fit in my budget, or make them if possible.
It sounds like you are just about there since you have hammered the metal over to resemble the bangle already. Hopefully you are hammering the blank onto your mandrel as one would with a stake in raising just keep going…with a little more intent and don’t ‘pinch’ the metal between the hammer and mandrel. If all else fails…cut off the offending portion LOL!!
Thanks for the feedback. Cutting off the ragged, ruffled edge is certainly an option.
I kept working on it today, and I’m getting better! I’m doing OK making bangles that are about 5/8" wide. I’d like to be able to go wider – maybe my skills will catch up with my imagination with practice.
I think what would help would be a swaging block (sp?) that conforms to my tapered mandrel. Does anyone have any ideas about where to buy or how to make such a thing?
A DIY hardwood swaging block is certainly possible. Use oak or another suitable hardwood. Get a block of the require size and use a bandsaw or jigsaw to cut out a rough outline of your mandrel. Get some sandpaper in various grades and wrap the mandrel with the coarsest grade. Rub the swage block across the mandrel to make the cutout in the black fit the mandrel exactly. Run through the grits until the block is suitably smooth. A labor intensive, but easy way to make a block.
royjohn
Only slightly off topic it is also possible to make swage blocks for tubing of various sizes if you have the required sizes of drills. Just take two thick planks and fasten them together (you can screw them together and later remove the screws). Then drill the holes through both planks (the holes are centered on the line between them) and you will have two swage blocks with half hemisphere cross section holes in them. This works in any size if you can keep the holes drilled straight. A drill press helps.
royjohn
What you want to do in forming cuffs is hammer your end sides first to mandrel On both side. Then you hammer the middle section to your mandrel…hope this helps…
Thanks, Johnny - I’m going for bangles not cuffs. The advice about doing
the ends first for cuffs is good, though. I’m sure I’ll be making those,
too, at some point.
Thanks, Philip! I had seen this demo’d a few years back. The demo guy
then took the ring and turned it back into a washer. He had effectively
turned the washer inside-out. Very cool! That’s where I got the idea to
try it on bracelets.
If you think of a bangle as a large ring, it will be easier to visualize. When sizing a ring on a mandrel, you hammer the ring until it fits, and then reverse the ring and hammer until it fits. That regulates the size and takes the mandrel’s taper into account. With your bangles being as wide as they are, I’d cut the circles with the outside diameter slightly smaller than the intended final size. That would give some room for adjustment on the mandrel.
Still plan on making a swaging block.