Karen, They make emery in the form of thread ( Name escapes me). This
works well to get in a pierced area and for polish some laundry cord
(soft cotton) with compound applied works quite well… Karel
about bending rings with a wood block and mandrel: tell us more
about the wood block. do you make several depressions to fit
different sized rings? how big do you make the depression/s? what
do you make the depression with? my partner suggested a router. as
you can see, i have no experience with wood working either.
oh, i have another question about forming rings: i have just
recently made rings with 8mm bands in my jewelry making class. the
bands were wide to accommodate a design that i had roller printed. i
noticed after i had soldered and formed the rings on a tapered ring
mandrel that the edges of the band were flared upward. i am
imagining that i inadvertently did this when i was malleting the
rings on the mandrel-- that i hadn’t allowed enough room for the
metal to move on the wider part of the mandrel. i wasn’t
successful correcting the discrepancy, even though i re-annealed and
focused the mallet on the side of the ring with more space to move.
what caused this problem? what could i have done to correct it?
thanks,
jean adkins
about bending rings with a wood block and mandrel: tell us more about the wood block.
Jean, don’t turn it into rocket science. the wood block can be
almost anything you like. If you prefer half round grooves which
will conform to the mandrel and band, then fine. Occasionally this
will be useful, though more often for forming short bits of metal to
the desired curve, than for just bending around ring blanks. I have
a block made from maple, and another from phenolic that are exactly
this way, made by using a large set of forstener wood bits (these
bits drill flat bottomed holes, and can be had quite large, up to
several inches in diameter) drilling a line of graduated holes, then
sawing the blocks in half along the line of holes. gives you two
matching blocks. These are useful when actually forming the needed
curves in various, often smaller, pieces of metal that don’t bridge
the gap across the depression.
But for just bending ring blanks around the mandrel, it’s the
mandrel, not the wood block, that actually determines the shape, as
the metal bends up and around the mandrel. for this, one can just as
easily use a block that has a V shaped groove in it, rather than a
half round groove. With that, the mandrel simply presses down into
the groove till it meets the mating width of the groove, so the one V
groove works with any ring size. All that’s needed is that the two
sides of the block contact the metal before the metal that’s under
the center of the mandrel bottoms out. If the metal under the
mandrel is over a gap, supported on each side of the mandrel, then
hitting the mandrel down into the gap will bend the metal. You can
get this effect in any number of ways. it doesn’t even have to be a
groove in one piece of wood. Can even be two pieces of wood just
placed near to each other, with a gap between, though if the metal
is already bent and you do this, it will just drive the wood blocks
apart… The reason it’s wood, or similar, is just so it’s softer
than the metal, and won’t mark it.
...t the edges of the band were flared upward. ... ... what caused this problem? what could i have done to correct it?
One of the things about bending sheet metal (any shape, actually) is
that in bending, the inner curve of the bend is metal that’s being
compressed in on itself, while the outer curve is being stretched,
and only the centerline of the stock stays the same length. But at
the edges, some of the metal that’s being “upset”, a term for
compressing in itself, which makes it thicker, by the way, instead
takes the easier route of squeezing out towards the side a little.
What that does is to require the outer surface to stretch less as
well, and it slightly flares the outer edges of the strip. Now,
added to that, if you forced the ring up on the mandrel and malletted
it hard, then yes, you also flared the edges a bit this way too.
You CAN correct it as you describe, but annealing the band, and
holding it over a mandrel at a position where the mandrel is slightly
smaller than the inner surface. this lets the band sit flat down on
the surface of the mandrel without being forced out at the ends.
malleting just along the center of the ring can slightly stretch the
center, making the band flatter. Easier to do with a steel hammer if
you can afford the hammer marks.
If you’ve got a steel forming block in the shop, these are steel
blocks with half circle grooves cut (much like the wood ones we
discussed above). If you put a mandrel slightly loosely into the ring
and mallet on the mandrel (not the ring) to force the ring down into
th groove, this can also planish that surface flat again.
and a final, somewhat more drastic means is to support the mandrel
in a vise or something, so you can hold the ring right at the end,
with about a third of it off the end of the mandrel. Gently hammer
the edge of the ring over air like this, and it will bend down a
little bit. Try not to let the inner edge of the mandrel scar up the
inside of the ring too much. You might want to round over that edge.
once you’ve gone all around a couple times and reduced that outer
edges average diameter, then hold the ring fully over the mandrel,
but in a not quite tight position, and mallet the whole width to even
out the kinks.
Peter
about bending rings with a wood block and mandrel: tell us more about the wood block.
Take a piece of 4" x 4" hardwood and drill a series of holes. Saw it
in half, and you have 2 groove blocks. Drill sizes (suggested) 32 27
24 21 15 12 millimeters.
Brian
B r i a n A d a m
B u s h J e w e l l e r y W o r k s h o p s
Auckland NEW ZEALAND
www.adam.co.nz/workshops/
His solution was to limit what we allow the students so that they don't damage our tools.
This is somewhat like the very common, almost prevalent practice is
the U.S. art school programs, and perhaps elsewhere, of teaching
students to lift a file off the metal on the backwards, return
stroke. While the teeth of the files do last a bit longer this way,
an important consideration perhaps when students are all using studio
supplied files, it also slows things down and somewhat reduces your
control over the process. Most commercial/professional jewelers
quickly learn that’s this isn’t needed, and seldom suggest it, much
less insist on it. But some students can be slow to learn that the
reason they were taught this had to do with the economics of art
department budgets, not proper technique.
While it’s true that some students will find almost any possible way
to damage tools unless you manage to second guess them first and
forestall it, I frankly believe that this too, is an essential part
of the learning process.
and besides. most quality mandrels these days are heat treated to
sufficient hardness that they’re not all THAT easy to damage (though
i’ve managed it a few times myself)
Peter
They make emery in the form of thread ( Name escapes me).
I don’t know the name of the thread, but the activity of using it is
called thruming.
Elaine Luther
Hi Brian, I am sure as you said it was more about “personality
politicks” than anything else. Over the years I have looked on with
curiosity on the divide between contemporary and traditional
jewellers. Coming from an art/design background and traditional
training I have always felt a well made piece of jewellery makes
little difference how or who made it, it still remains a good piece
of jewellery. Some people just get stuck in a groove (excuse the
pun). By the way I am in Auckland next week are there any exhibitions
worth seeing? Chris
They make emery in the form of thread ( Name escapes me). I don't know the name of the thread, but the activity of using it is called thruming.
Hi All A cord abrasive is manufactured by a company called
Mitchell’s… It comes in a number of grits and sizes, and some
industrial supply houses carry it. If not, Mcmaster-Carr the catalog
house has it, as well as the thin tape form.
An alternative is to get a ball of kite string and rub a length of
it see-saw against a block of rouge or tripoli or whatever to charge
it up.
Let the polish set up, and bingo.
Gary W. Bourbonais
Jean, don't turn it into rocket science. the wood block can be almost anything you like.
Rocket Science is easy compared to this little discussion! Could
someone please draw me a picture of exactly what you mean by these
wooden blocks and mandrels as I for one am totally lost by the whole
descriptive thing going on here. You know what they say…‘A picture
tells a …’ I am really interested in this discussion as I have yet
to try such a project and am seriously considering one in the near
future. Regards Mark Vardy (www.silvar.co.uk)
about bending rings with a wood block and mandrel: tell us more about the wood block. do you make several depressions to fit different sized rings? how big do you make the depression/s? what do you make the depression with?
I would get a hardwood block 2 X 4 and drill holes cross grain in
whatever size you need.
Then cut the block in two pieces where the hole is.
Wood drill bits are available in 1 / 16 of an inch size.
The blocks should be 4 to 6 in. long .
If you want the depressions to be very hard and very smooth, head a
iron rod the diameter you need the depression to be and hold the
blocks together until the wood smokes.
You will have 2 of each size.
Make friends with a woodworker .
ROBB
Rocket Science is easy compared to this little discussion! Could someone please draw me a picture of exactly what you mean by these wooden blocks and mandrels as I for one am totally lost by the whole descriptive thing going on here. You know what they say..'A picture tells a ..' I am really interested in this discussion as I have yet to try such a project and am seriously considering one in the near future. Regards Mark Vardy (www.silvar.co.uk)
the mandrel is the tapered steel rod, often marked with ring sizes,
which we use to form rings on. I seem to recall some in the UK call
them triblets, or some such. Not a specially made tool just for the
wood blocks. Could also be ANY steel rod tapered or not, of a
diameter to fit insde the proposed ring size.
the wood block is simply any piece of wood, though hardwood is
common, on one surface of which one has cut either a V shaped
groove, or a half round groove across the top. If, instead of wood,
you could imagine a lump of clay. Flat surface on top. Now take your
mandrel, or a steel rod, and press it down halfway into the surface,
and lift it up again. You’ve got a groove running across the top of
the flat surface. In the wood, it’s the same idea. this example
would give you a half round groove. It could also be a V shaped
groove if you like.
the groove need not be any particular length, so long as it’s longer
than the width of the metal stock being bent into a ring.
Peter
mark asked about a picture or diagram of the wooden form used to
bend the ring shank.
brian adam was one of the people who responded to my question.
there is a description of how he does it along with diagrams on his
website. here is the address for the diagrams:
http://www.adam.co.nz/workshops/techniques/5_1hr_ring.htm .
he also gave guidelines for the overall size and drill sizes:
Take a piece of 4" x 4" hardwood and drill a series of holes. Saw it
in half, and you have 2 groove blocks. Drill sizes (suggested) 32 27
24 21 15 12 millimeters.
jean adkins
All, I made a ring bending wood block from an old dog wood tree limb
2.5 inches in diameter and 4 inches long that had dried for a couple
of years. First I drilled a one inch hole in the center about an
inch deep. This was followed by 4 other wood drills centered on the
drill hole before it, each of different diameters and each about an
inch in depth ending with a 1/2 inch hole. I cut the limb in half
giving me two blocks with half round impressions in very hard wood.
I’ve been using one of these for nearly 10 years and its still good.
I also flattened the other side of the block from the impressions for
use as a wooden anvil. Makes a very useful tool.
Cheers from Don at The Charles Belle Studio in SOFL where simple
elegance IS fine jewelry! @coralnut2
Ring bending tools are a staple in trade shops all over the US and
Europe, perhaps elsewhere , as well. If one has the difficulties
described, in a past post, with the tool you are either using it
improperly or there is something wrong with the tool. This method of
using a wood block is the slowest of three methods that come to
mind.
-
The fastest would be two pairs of chrome plated half round
pliers, I’ve made bands this way.both as a manufacturer and as a
custom Goldsmith. I know it is possible to bend up to 10 X 2.5
Platinum 90% Iridium 10% this way, at least, if properly annealed. -
Some major reasons that ring bending tools are used is if the
ring needs to be brought up without twisting , as would be the case
in meeting an underbezel or similar project. another would be
particularly cumbersome pieces, that need to meet flush.
The wood method may be good for a low volume shop or someone just
starting out who’s working on a tight budget. I find it not all that
durable and loses it shape quickly. I do like wood for dapping down,
and use it for dropping down simple forms or applique that lacks
fine detail, at least those that cannot be handled in a dapping
block.
My aim may be different form the other person posting so; my aim is
to boost productivity while maintaining quality craftsmanship.
DMA
There was mention of a stylus for transfer, in a past post, as well.
When I draw, with a drafting pen into tracing paper, a slight
depression is formed. When the depression is covered with graphite,
using my finger works fine, in transferring the design to metal,
that has transfer wax 1st and a coating of talc on that. Using a
stylus over this would be a disaster if the design were fine. When
choosing a pen to draw the fine line of a design, it is positive to
use a pen thickness as close as possible to the thickness of the
sawblade, to be used to pierce it and / or the width of the line to
be cut with a graver. Using a scribe or a stylus to do this, could
very easily, move the line or create a variation in the thickness of
the line, leaving a bad track for the tool to follow. If one needs
to darken the line, it would be prudent to use a drafting pencil the
same thickness as the line or draw with the same pen through the
paper after the graphite has been applied to the reverse side. If
I’m using a # 8 saw blade, or a fine lozenge graver, I use a
drafting pen; finest pinpoint available, and a mechanical drafting
pen in the same size range.
DMA