Cutting murini

[Anne_Londez]

Does anyone have a magic trick for cutting thick (10-15 mm) cane into murini without having to fire polish them ?

[Vince]

I think that a diamond saw followed by a flat lap polish would be the only alternative for murrini that thick. I'd suggest sending a note off to Loren Stump with the same question. He probably has as much experience with that sort of thing as anyone and knows the subject so well that whatever he says can be taken as pretty much the right answer. I always get ragged edges on murrini in the 5-8 mm range using cutters so for larger ones I think there needs to be a saw and flat lap in the equation someplace.

Vince

[Kuehlmorgen_D]

Hi Anne

Vince has the answer. I would like to know what type of glass you are using (opaque only or with larger parts in transparent or clear). The polishing is not so fuzzy for the opaque glass but the clear shows everything. Clear goated slices should be mechanically polished with cerium oxide for inclusions in paperweights. Opaque slices should be OK if they are grond with fine grit.

It depends on the way of use how exactly the glass has to be ground and polished.



Dietmar

[Anne_Londez]

That's what I am tryingto avoid Dieter. I want to use larger slices but it's not a complicated time-consuming murini, only I want at least 50 slices on the same bead... so polishing by hand by whatever method is out ! No clear but some transparents.

[Kuehlmorgen_D]

Hi Anne

Can you cut the slices you want from a fresh rod of Effetre glass? This is a "just for practice" question. If it works well from a regular rod you might have a chance with annealing the cane before using the nippers. An other idea is to cut double thickness first and cutting them in Half in the second step. This might reduce the jagged edges.


Dietmar

[Anne_Londez]

The thing is my nippers are too small for that, the cane won't fit in there. I was wondering if someone had ever tried making a cutting machine of some kind, maybe along the lines of those used in the factories to cut the rods. I've experimented with nails and hammers but without any success so far !

[Vince]

Anne,

here is something you can try. Obtain a small tubing cutter, such as plumbers use for cuttting copper tubing. The small ones will take sizes up to at least 25mm if not larger. Note that the cutting wheels on these cutters are usually NOT tungsten carbide, but a good grade of hardened tool steel, usually termed "High Speed Steel" or HSS. The device has a screw mechanism for slowly tightening the cutter against the tubing or pipe while turning it to cut. I would make a small nick with a file in the murrini stock where you want to make the cut and then place the stock in the cutter with the cutting wheel in the nick. Slowly tighten the screw mechanism and the murrini should split at the nick. The wheel will eventually become damaged and unable to cut, but these tools don't cost very much (they can be had here in nearly any hardware store for about $5 or $10) and you can throw it away when it no longer functions. If you can find one with a carbide wheel, then it should last indefinitely.

I'm not certain this will work as well as you would like, but it is an inexpensive way to try to solve the problem.

Vince

[Kuehlmorgen_D]

Hi Vince

Your idea sounds interesting. There must be a chance to replace the original wheel by a spare wheel for a disc nipper. If I get that tubbing cutter for a decent price I'll try the trick with replacing the wheel.


Dietmar

[Vince]

Dietmar,

That would work. The only likely problem would be to ensure that the axle of the wheel was the same diameter as the hole in the wheel as you are not going to be able to easily enlarge the one in the carbide wheel. On the other hand the tubing cutter will be easy to machine as the body is usually something like cast aluminum or in the better models cast iron, both easily machinable. I am certain that would work well. That might also eliminate the need to first nick the murrini stock with a file. You can cut all sorts of roundish things with one of those tubing cutters. I even use one to ensure a perfect match of coaxial cable braid with large size coaxial cable connectors.

However, even with the best of these tools that cut things, you are still going to be dependent on the nature of glass and it may or may not shear in the manner you would prefer. Still, it is worth a try.

Vince

[Debby_Weaver]

Sounds like a tool for Craig to come up with!
Debby