The key to success in eliminating the need for aggressive sanding....

[robo hippy]

Thanks John, I am always curious....

Totally off topic, but MM, if I remember you are Polish and I ran across this young woman from Poland who is an incredible bass player, more jazz type but stunning.....

View: https://www.youtube.com/watch?v=S2QmtENFh2Y

Hey Michael Mouse, I am guessing you didn't see this because I didn't tag you and used MM, and you didn't respond...

robo hippy

 

[Bill Boehme]

I suspect that MM was talking about the type of circular cutters with a raised lip used on the Rolly Munro guarded hollowing tool and the cutters used on Hunter tools. If you haven't tried to raise a bur on a piece of tungsten carbide yet, don't bother because it can't be done. You would have as much success doing that as you would trying to raise a bur on a diamond.

Think of tungsten carbide (chemical symbol, WC) being comparable to a concrete slab where the aggregate is microscopic particles of tungsten carbide and the cement is cobalt or sometimes nickel. It's more like a ceramic than a metal and it is extremely hard ... nearly as hard as diamond or CBN and far more brittle. You might manage to chip the edges of WC, but you won't deform it into a bur.

 

[john lucas]

Thanks Reed that is cool. I watch a lot of fingerpicking guitar videos but haven't seen a bass player do it.

 

[Douglas Ladendorf]

Nice take on Eric Clapton.

 

[Steve Worcester]

Well, I may have to try to find a flat carbide insert to see if I can burnish a burr on it. I can do it with the tangung, which is a cast particle metal similar to carbide, but not as fine grained as the 'micro' or 'nano' grained carbide that is used on the modern carbide tipped turning tools. I can turn the old one down and bring it up again which does 'refresh' the edge. Tantung is very brittle similar to carbide so that if you drop it, it will chip or shatter. I have sharpened some carbide tips on my CBN wheels, and it does leave a tiny burr, though I haven't done much of that. No idea how long the burr lasts...

MM, what is a simulated burr? Like a tiny burr from the grinding wheel, but not the burnished burr??

robo hippy

The flat inserts, like used on planers and easy wood, I don't think is a micrograin carbide.
Hunter type inserts are and can't be sharpened the same way, and I think micrograin would shatter if you tried to burnish a burr on it

 

[robo hippy]

Well, I know there are carbide cutters that are shaped into a cup type shape as in concave. Not sure about the Munro hollowers. The tantung I use is very similar to carbide, a particle metal and very brittle. I can burnish a burr on it. For sure, if I really bear down on it, I would expect it to chip. Not sure about the carbide, but I would expect to be able to raise a small burr. It doesn't have to move much to form one.

There was a young man in our club for a while who was on crutches. I commented to him that he had a bit of a hitch in his giddy up. He said, 'Yea, I got blown through a wall. The doctors told me I would never walk again. But, you know how you get an Army Ranger to do some thing? You tell him he can't." Kind of made me think that in one sense, hippies and Army Rangers may have some thing in common. I was told I could not raise a burr on HSS with a hand burnisher. No problem. Now, to find a cutter and try it out....

robo hippy

 

[john lucas]

I took my EZ wood flat tool and sharpened it this morning. Diamond hones work very well. I just took the cutter out and put it in a small vise that will tilt. I tilted it so I could file more or less straight across. Tool just a few seconds to put a new edge on it. then I tried to raise a burr using the diamond hone. Could not feel one. It just rounded over the edge. I put a fresh new edge on it and then tried to use a steel to raise a burr. All it did was chip the edge.
On another note a few years ago I tried to sharpen Hunter cutters. Could not do it. The edge just chipped. I tried a whole bunch of different sharpening mediums to see if there was a way to clean up the edge. Nothing worked. On the plus side they hold an edge much longer than The other carbide cutters I have tried.

 

[Bill Boehme]

Tungsten carbide for all practical purposes is a ceramic material although it doesn't exactly fit into either category of being a metal or a ceramic. Cutting tools made with it use a high pressure molding and sintering process where sub-micron carbon particles are are actually embedded inside the lattice structure of tungsten particles and then are bonded together with cobalt metal particles as the "glue". The amount of cobalt ranges from 2% to 20% depending on the desired hardness ... Less cobalt is harder. The WC grain size effects impact resistance and sharpness. Fine grain sub-micron carbides can be molded to the most acute angle sharper cutters, but are the least impact resistant. Larger grain carbides on the order of one micron are more wear resistant and have greater impact resistance. Larger grain size and greater percentage of cobalt binder go hand-in-hand as you might suspect.