Carbide Rotary Burnishers

Am I missing something? I bought a set of four, a hundred bucks, and
I couldn’t get them to do much in the flexshaft.

I wound up just sticking one in a pin vise and used it manually.
Nice finish but I was hoping for faster work in hard to reach spots.

Anyone have these down? Clue me in?

TY

I wound up just sticking one in a pin vise and used it manually.
Nice finish but I was hoping for faster work in hard to reach
spots. Anyone have these down? Clue me in? 

Now that the huge, eggshell-like trillion solitaire platinum
earrings are out of the way, life is a little more relaxed. I’ve
never used the rotary carbide burnishers, but assuming they are being
used for porosity removal, there’s a better way, anyway. Get an old
bur or anything that’s tool steel - not a mandrel because they’re
soft. Put it in a vise, heat it, and bend the end of it to a 30
degree or so angle. Re-heat treating it is optional. Then grind a
face on the bent end that has rounded edges, and polish it. In the
flex shaft it will rotate and go “whap, whap, whap”, and works
perfectly against porosity in gold and other metals, too. I have one
that’s the full shank size, and one that’s made from a small bur that
has about a 1.5 mm face, for tight spots.

I was told these needed to be used at about 30000rpm, so a flex
drive won’t do it. You will need a micromotor or similar, I could not
get the one I bought to do anything either, if it is any comfort.

regards Tim.

I’ve used these, if we’re talking about rotary carbide burrs, not
burnishers, for a very long time. I use them in a Foredom handpiece
that has collets, not the #30. The shafts are too thick to use in a
micromotor.

As for speed try different speeds to find the speed that cuts
efficiently. It’s definitely not 30000. As a general rule the smaller
the burr the faster the speed, and larger burrs run at slower speeds.

KPK

As for speed try different speeds to find the speed that cuts
efficiently. It's definitely not 30000. As a general rule the
smaller the burr the faster the speed, and larger burrs run at
slower speeds. 

I AM talking about rotary carbide burnishers,see link below

3/32" shank, best used at 25,000-35,000 rpm Cooksons have 4 shapes in
their cat

regards Tim Blades.

'Twas a set like Rio Grande item 347103 found on page 271 of their
tool catalog

there are four shapes. as you can see it’s a burnisher like we use
for plat. finishing but fits in the flexshaft. Made by Pfingst so I
thought it was ‘legitimate’. I didn’t find any advantage to the tool
spinning vs manual drawing. In fact manually came out nicer, I think
because you are actually plowing the surface.

If I don’t find the technique I may just reshape them to handy dandy
profiles and use them manually. The barrel shape particularly looks
adaptable.

Thanks for the input.

Tim,

Aha!, none of the catalogs I looked at mentioned running speed.
Would have been a nice thing to know before ordering.

Hmmm, I wonder if diamond flywheel overdrive handpieces will turn
that fast. Something to search at lunch!

Thanks much

3/32" shank, best used at 25,000-35,000 rpm Cooksons have 4 shapes
in their cat 

Are you running them at the stated 25,000 - 30,000 RPM ? In my
micromotor at 30,000-50,000 RPM they work fairly well to burnish
with a very light touch, at lower speeds however they are not very
useful in a hand-piece but work well in a pin vise as a manual
burnishing tool.

just my .02 cents

James Binnion
@James_Binnion
James Binnion Metal Arts

360-756-6550

Back when I was in dental school and learned how to cast and finish
gold, we learned about burnishing. I could never learn how to correct
a defect like porosity or a short margin with a slow speed burnisher.
I am not familiar with the high speed burnishers.

I did know about using a dull round bur knocked off center, but
again, it never worked for me. I had to do bad castings over again!

Charles Friedman DDS
Ventura by the Sea where it is finally raining!

Hi Neil,

you can get cheap dental drill micro motors or nail polishers on
E-bay, probably not built to last but I found one at about $60

regards Tim.