I have been struggling to cut a seat in 22K tubing with a setting
bur. This was not a problem a few years ago and has more recently
become impossible. I have called the techs at both Stuller & Rio
Grande and they usually suggest another brand of bur.
What happens is the bur polishes the metal rather than cutting it.
The burs are so fine and they seem to get gummed up in the 22K gold.
I found an older bur that I used to use and counted nine cutting
edges with one cutting edge that seems to stick up a little from the
other cutting edges which forms something similar to a brad point
twist drill bit; these old burs work beautifully and remove a long,
fine ribbon of gold.
The newer burs seem to have 16 or more cutting edges, which in fact
do not cut 22K gold at all.
Has anyone else run into this problem, suggestions of where I could
find setting burs with fewer cutting edges (like 9)?
I have been struggling to cut a seat in 22K tubing with a setting
bur.
Oh thank you for writing this. I thought it was just me! Waiting for
someone to come up with something. I haven’t. Newer more technical
isn’t always better!
Lisa (Studio expansion still under construction. I hate contractors)
Topanga, CA USA
I have been struggling to cut a seat in 22K tubing with a setting
bur. This was not a problem a few years ago and has more recently
become impossible. I have called the techs at both Stuller & Rio
Grande and they usually suggest another brand of bur.
We just happen to have Phil Poirier here in the building this week
teachingsome Hydraulic Press classes. He works a lot in 22k and so
we asked him. He had this to offer.
He said that a bur with less teeth will not help, it will chatter
and you will still get the same burnished effect because the bur is
rotating too fast with a flexshaft. What he recommended is that you
cut the seat by hand only making a 1/4 turn at a time then clean the
bur on a file cleaning brush after each 1/4 turn.
I hope this is of some help.
Mark Nelson
Rio Grande Technical Support
1-800-545-6566
Microcopy a dental lab supply company makes a depth cuter that is
ideal for tubing seats- they come in a pack of 25 single use burs
(as for dental use) but their diamonds are deBeers sintered natural
diamonds and don’t clog. They have a spiral style and a non spiral
style, well brands, that have a variety of styles that are
appropriate for seat cutting. another brand I like is Piranha- they
too have non-clogging cutting heads and a variety of grits as well
as styles- some better than others for tubing of high karat gold. The
spiral burs emit a ribbon of metal that is easily collected rather
than particles flying all over. the depth cutters also serve as a
guage of sorts. I can make two tube settings using a single bur due
to where the cutting surfaces are located on the shanks.
Alternatively they (microcopy) makes a single cutting head on a
shank eliminating the potential for making two identical seats on a
length of tubing. rer
I was posted the original question. After years of dealing with this
problem, and days of laboring over what is different, I think I have
come up with a few thoughts.
First, the new burs are vertically cut, and very fine. My conclusion
is they are not design to remove very much metal. When I looked at my
older burs they are cut on an slant, which seems to help in removing
the metal, in addition, they do not have as many cutting edges.
So, yesterday, I started by pre-cutting seats with a smaller bur, so
I removed some of the metal with a smaller bur, then used the final
bur to cut the desired seat. Although the newer finer burs still
suck, this worked. Here I am taking two step for what should be a one
step process.
Yesterday I order yet another batch of burs based on the very
unenthusiastic advice of a tech at Stuller. I will let you know if
this style works any better. I also order more burs from Rio.
Brand new burs that haven’t worked are:
Lynx by Meisinger made in Germany
Dentsply Maillefer made in Switzerland
Panther
I am using a Foredom Micromotor to cut the seats.
I have a question for you, are you using 22K tubing? I only work in
22K, but I can no longer find a supplier for 22K tubing, if you are
working in 22K who are you getting your tubing from? I had to order
10ft of tubing, all the same size, that I had no say in wall
thickness or diameter in order to obtain said tubing. With 10 feet of
22K tubing on hand you can see why I am desperate to make the tube
setting work.
If you’re having trouble with 22k tube, and the suppliers aren’t
giving you any choice over any of the details that really matter,
you might want to draw your own.
Once upon a time, Bonny-Doon used to make a small deep draw kit that
was expressly designed for creating (smallish) seamless precious
metal tube that would later be drawn down into tubes of whatever
diameter. If you don’t already have a press, you’re looking at about
$3500 or so to get the tooling, but then you’re set. If you’re
ordering 22K tube by the ten foot stick, it won’t take long before
you’re money ahead.
I don’t know if BD is still making the mini deep draw kit or not,
but it’s certainly something I’d look into.
I’m mostly unaffiliated with BD, except that both Lee and Phil are
friends.
I don’t work in gold nor do i set stones but I do know that when i
asked my dentist for discarded tools a few years ago he gave me a
treasure trove of burrs and cutters - mostly smaller than i had ever
used before and a grand variety of useful shapes. I had tried some
crude direct carving in metals many years ago with burrs in my
flexshaft. Those were burrs ostensibly designed for cutting in metals
but I had a poor rate of success. For one thing I had no teacher to
guide my floundering experimentation and I didn’t do any research -
just went at it with my ignorant enthusiasm - made a few pieces
barely good enough for my low standards and acquired a few scars on
my left hand fingers and figured i had no talent and no luck in this
department. But I tried the dental burrs. I have not made an art of
using them - but I played with them a bit and the difference in
experience was as night and day. I used them on copper, brass, and
silver. They were palpably much easier to use - conspicuously more
controllable, mostly non-clogging too. I haven’t had time to do
extensive work with these as i’ve been busy building a new house,
studio for my wife and workshop for me these last two years - but i
look forward to trying them again. I’d look into using dental tools
if I were you.
The burs you are referring to with the slanted cutting edge and
coarser tooth pattern sound like high speed steel burs. Try looking
for high speed steel burs.
Julie- We make our own platinum tubing. Sometimes high karat gold
when we need to. It’s all very doable, but requires a draw bench. We
fuse our seams so that there is no solder in the tubing.
Haven’t been on this much so. but if you are cutting seats in
prongs, first mark with dividers for height then I would use a saw
blade cut in 25 percent of the way and then open it up with tri
square needle file for the seat. Clean up with 40 or 41 flat graver.
Errrr. automotive “H” frame presses aren’t exactly the same thing as
metalsmithing presses. Yes, they’re both 20 tons, but that’s about
the limit of the similarity.
The auto presses are for knocking bearings on and off of axle
shafts. They don’t really care about alignment of the head, and the
platens (such as they are) are small and pretty wobbly. If that’s
what he’s got, you’re going to have trouble with it, and I guarantee
you’ll destroy a deep draw kit if you try to run it in one of those
presses.
(It probably won’t even mount without some serious frankensteining.)
You can probably do some light doming with it, but that’s about as
much as I’d be willing to try.
Fwiw,
Brian.
PS–> I’m sure the differences between auto/harbor-freight presses
and BD or Potter presses has been covered exhaustively in the
archives. Well worth your time to go hunt it up.
.... automotive "H" frame presses aren't exactly the same thing
as metalsmithing presses. [snip] You can probably do some light
doming with it, but that's about as much as I'd be willing to try.
Securely attaching the tools may take some work, but Bonny Doon
mushroom formers work really well with a shop press, and without
pushing things. (Sorry…) Same thing for the Bonny Doon synclastic
bracelet forming kits. I apply more power with those, but I can’t say
what portion of the 20 tons.
Yes, you can do some things with “H” presses, but this all swerved
onto the topic of presses when I mentioned a deep draw kit for
tubing. The big dapping tools don’t care about alignment very much,
while the deep draw punches care very much indeed. So what works for
one technique doesn’t guarantee that another will work. (The issue is
getting the punch centered in the hole of the die, and keeping it
there, as well as keeping the punch perpendicular to the die.)
It also depends on the press. I’ve seen some professional auto
presses (Dake) that were a bit wobbly for metalwork, but generally
OK, and then some of the ‘same’ press from our friends in the
dockyard freight business that were just marginally better than
nothing.
Having taught hydraulic press workshops all over the country, I have
encountered all kinds of presses. I think that a basic press will
usually work for the most basic processes, such as dapping and
cutting dies, but for more specialized tools, such as deep draw
tubing formers, a better press will not only work better, but also,
protect your investment in the special tools.
I DO understand the desire to not spend more than necessary for a
press. Personally, I started with a cheapie, and then upgraded to
Bonny Doon when I could see for myself the advantages of a better
press.
Safety Plug: Whenever you use ANY press, please remember that it is
POWERFUL. I like to say that using a hydraulic press is sort of like
driving a car. Pretty safe if you’ve been trained, but there is
always risk of an accident----be focused on what you are doing
whenever you use a press.