I just have a couple new-person questions about forming rings. I am
trying to do a simple wide band with a flanged edge. I’m doing well
up until I try to make the ring very round. When I try to get a ring
into a very round shape on the mandrel, the ring itself is always
getting stuck on the mandrel. When I try to get it off, the pressure
makes the ring not round again
On the flanging part, one side inevitably gets more rounded than the
other. It’s not equally flanged all the way around. I could go with
this and just call my style “organic”
Sounds to me like perhaps you’re putting your flange on before
forming? That could be causing the distortion because the force of
rounding works primarily on the main body of the ring, the part in
contact with the mandrel, which is usually the innermost part of the
shank. You might try rounding in smaller bites. Flip the ring over
frequently.
But if you’ve got a distorted ring and want to save it try
this…use a large tapered bezel punch of correct size and tap the
punch into the finger hole. The ring should rest over a suitably
sized hole to allow for the point of the punch. The punch has a much
faster taper than a mandrel so it will contact just the edge of the
ring. I’ve got one here if you’d like to borrow it before investing
in one. They make the punches in two tapers, 17 and 28 degrees(I
think). Come to think of it a large dapping punch might work too.
To unstick a jammed ring there are two ways that work for me. Brace
the mandrel solidly on the bench or stump, preferably with the edge
of the ring resting on the edge of the bench, and pull the mandrel
slightly toward you then whack down hard with a rawhide mallet
straight on the ring. This will cause a slight expansion of the
ring. You can also tap sideways on the ring, like drawing the mallet
along the mandrel toward the small end, hitting the ring in midswing.
Some may frown on this though…I have a very large milling file
(10") with a safety edge that I use in that manner, for really stuck
rings. I suppose a brass mallet would work the same way, but I’m too
cheap to buy one.
Do you mean. Kim, by flanged that your rings have a rim at top and
bottom?
If they do, is it possible for you to do what I do, which is solder
the rims in place after the main ring has been rounded? really, this
is like soldering a ring on top of another ring, or two rings on one
in the case of a standard ring with rims.
I always use two mandrels. I use a regular mandrel to get the ring
close to the size, then a step mandrel (I have two, in half and full
sizes) to make sure the ring is not conical. Would that help?
If the flange is a result of forming then hammering within the
flanged rims with an appropriately sized hammer on a step mandrel
should work.
Could you make a tool of a block of wood, Delryn plastic or nylon?
Shape it so it fits the mandrel and gently nudges the ring off by
applying a small amount of pressure evenly round a good part of the
ring edge.
I’d propably start by taking a piece of 100x50mm pine and drill a
25mm or 30mm hole in it with a wood drill. Then saw the block in
half. You get a groove in each half. Try that as a nudging tool.
Sounds like you need to anneal the ring. Flip it on the mandrel as
you’re beating it into shape so it’s the same finger size on both
sides.
For the edge, (I think you mean tappered edge) you’ll probably need
to chuck up the ring in your handpiece and spin it against an
abraisive. Or, you can use one of those drum sander things and work
taht around the ring. They come in various grits, so you’ll have to
work your way up in grits to hide the file marks. If you’re doing it
this way, I’d use a divider to make a line around the ring so you
know how far to sand.
