I'm almost certain that normal turning tool will rip the cork to bits.

You need something very sharp, set to cut with a slicing action.

… a Stanley knife blade might do the trick

For the holes; use a Cork Borer [sharp tube], which is/was standard School Chemistry Lab equipment.

MichaelG.

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Edit: Ian beat me to it.

Edited By Michael Gilligan on 29/01/2014 16:38:47

You might be able to do something similar using a larger diameter tube on the outside.

Russell.

Hello Allen.

I'm Portuguese and, as you may know, Portugal is the main producer of cork. Long ago I saw a movie showing a machine cutting bottle corks and as far as I can recall the tube like knife was rotating. In the movie **HERE** you'll see a working machine cutting bottle corks. The rotating movement is not clear. However you can see in the specifications table of a cutting bottle corks machine **HERE** there is a r.p.m. of " Velocidade das facas 1400 r.p.m." meaning knifes speed of 1400rpm. As I remember the knifes look very much like hollow punches.

Best regards
Dias Costa

Hi Allen,

Most chemistry labs. used to be equipped with a 'cork softener', I have not seen one for years, but as far as I know chemistry labs no longer use corks.

The softener comprised of two serrated wheels the centre of the small being offset from that of the larger.

By putting the cork into the largest opening and turning with quite some force the cork was squeezed. On removing the cork it was surprising how small a hole it would fit.

Jerry

From what has been described above, it sounds as if cork would be very difficult for most of us to machine using single point tools or blades.

I've recently been "machining" some vulcanised natural rubber strips. These are actually snooker table cushions and are very elastic (they need to have a very high coefficient of restitution) and pretty soft. I had to taper them at each end where they merge into the centre and corner pocket areas.

My first thoughts were to try some form of sharp blade (ouch!) but this was clearly not going to work. Even with a very sharp wood chisel and a smart blow, it's impossible to place the cuts anywhere near you need them and blend the surface acceptably. I also tried some very sharp tin snips and the result was pretty awful.

The solution in the end was to hack off the bulk of the material with scissors or snips and then use a belt sander to remove the rest. As you can see from the test piece, you can get a very reasonable result indeed. Believe me, this is a miraculous improvement compared to the first attempts with the cutting tools. Just keep yourself to one side unless you want rubber crumbs everywhere! Of course, this is what the professional snooker table restorers do.

I imagine something similar would work very nicely for cork. If I was planning to "turn" cork, I would probably mount a Dremel tool in the tool post and use a fairly coarse one of those sanding wheels.

Muzzer

Paul is spot on

when I started out in engineering we used to make pinch wheels for tape recorders. the rubber was bonded on to the shaft left in a freezer. Then ground down to the correct size finish was perfect May work with cork!

hugh

Hi Allen why not use rubber bands ?

Little OT, back in my aviation engineering days we used to fit a rubber seal with a hole though it in the fair leads for the tail wheel control wires, the bits of rubber were about an inch long by an inch wide and D cross section, the corners of the D were first cut with a knife, then finished on a wire wheel. When fitted a split pin was passed through the fair lead, and rubber block. Used to prevent the fertiliser etc., getting in and damaging the control cable.

The wire wheel maybe a bit harsh on cork, I'd try the bench grinder. Ian S C

I recently found myself needing to cut some cork into a cone shape, and after attempting to cut it down with a razor sharp knife, I discovered the best way was simply to chuck it in the lathe and, using a normal right-hand knife carbide tipped tool, machine it down with the speed set at the highest. In my case this was around 2650 rpm, this provided quite satisfactory results with all types of cork, reconstituted ones included.

For boring this also works, however as the bit gets smaller the speed needs to increase (obviously) so as to maintain high speeds at the cutting edge, and beyond some diameters this becomes hard to achieve. As a suggestion if this is the case, perhaps a power drill mounted in some fashion on the tailstock could spin in the opposite direction to the lathe chuck so as to increase the relative speeds between the bit and the work?

Anyone who's read L.S sparey's "amateurs lathe" book will know he actually devotes a section to the machining of rubber and cork and how to make razor thin cutting tools for it.

I believe the example he used was the machining of rubber feet he made for a friend/client once. I'm now at risk of one of the bookworms tripping me up. I don't know why i bother. 

Michael W

Edited By Michael Walters on 02/04/2016 21:08:01

I am surprised nobody has mentioned cutting fluids, unless I missed it. I've found that water makes a big difference in cutting both cork and rubber.