Chemical Tungsten Sharpener??

Is this a gimmick?

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It doesn't mention that it will sharpen Lanthanated tungstens, but if it actually works it sounds like it'd beat sharpening on a grinding wheel.

Reply to
Artemia Salina
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Ya know, I am a bit skeptical about all this stuff, I went and found a brand new CKTurbo-Sharp III tungsten grinder with all the goodies that sell for like $600.00+usc and frankly, I can do a better job on a bench grinder with a dedicated wheel and vacuum line, I thought this would be a magic wand and well, I guess the adage if you want it done right, do it the old tried and true way. This thing maked my tungsten's look like spear-heads and I'm pretty sure I'm using it right, I re-read the directions called CH for help and I was on the bubble.... In short the CK is in my tool chest awaiting someone to buy or trade it (It only sharpened five tungsten's) I would not sell it to a friend but someone who insisted on having one. I guess there is no shortcut for doing it right really. It looks cool but so does snake oil.. Heck, I still use "Pam kitchen spray on painted chassis parts so mig farts don't stick and burn, I learned that trick from an Ex-inmate who did a welding program in Statesville Penn. in Joliet, one of my favorite tricks... The tungsten's remain out nemesis, at least you can see the process on the grinder however.

All the best,

Rob

Fraser Competition Engines Chicago, IL.

Reply to
RDF

"RDF" wrote in news:j-2dnVAT5s-i snipped-for-privacy@speakeasy.net:

I bought a cheap 6" grinder from Harbor Freight, and use the wheels that came with it. I have an old Sears battery-powered, variable-speed, 1/4" drill that I chuck the tungstens in. The drill can turn really, really slow (maybe 1 rev/sec). I hold the tungensten in the fingers of my left hand, braced against the grinder rest, and adjust the position of the drill with my right, to get the desired angle. Watching the sparks tells me where I'm contacting the tungsten to the wheel. I can grind tungstens quickly and accurately with this setup. It does take a little practice to keep sweeping the tungsten across the face of the wheels, with the drill attached, to prevent grooving the wheels. But, that's true with any hand grind process. Anyway it works very well for me, and was cheap. I haven't had work this with really short tungstens yet.

Reply to
Ken Moffett

I agree 100%. Most tig grinders are crap, especially for 1/16 or .040 diameter electrodes that need very pointed included angles. As you described the geometry is off because they fail to support the electrode at the tip. The only grinder I tried so far that works well for these types of grinds is a the Sharpshooter.

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secret is the small rod that supports the tip just a few thousandths above the wheel. All the other ones I tried like the ones below fail miserably.
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Reply to
tomcas

The glassblower in my old chemistry dept. used to use sodium nitrite to clean and sharpen tungsten wires before sealing them into glass to make feedthroughs. I found a MSDS at

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which lists "diazotizing salts" as the active ingredient. Not sure what that is, but a search of the cas number they list turns up sodium nitrite so I assume that's what this is, just under an obscure name to stop people from getting it cheaper elsewhere (okay, no one cares but my old organic chemistry class is floating back to the top of the brain and you react sodium nitrite with aromatic compounds like toluene to form the diazo derivative which is useful to then convert into other things like dyes; you convert C-H to C-N2; so I guess you could call sodium nitrite a diazotizing reageant or salt). Anyway, if you heat the tungsten red hot and dip it into the powder it decomposes the sodium nitrite which then reacts with the tungsten to form an oxide which gets left in the powder, and a clean tungsten surface. If you use a fairly rapid dipping motion you get a point because the end of the wire spends more time submerged than the wire further back from the tip. How symmetrical and round the point becomes is a little bit of a crap shoot since any scratches or defects will lead to preferential etching, and I don't know how easy it is to control the taper angle. The 2% or less of other stuff like lanthanum won't bother the reaction. Anyway, chemically it will work, you just have to try it and see if you like the points you get. The glassblower heated the tungsten with his torch and a bit of a reducing flame; the instructions at dynaflux say to touch the tungsten to ground with about

1" sticking out of the torch to pass enough current through it to get it to glow red hot. That sounds to me like it's going to mess up the tip each time but I guess practice is the key.

Well, back to lurking. :-)

-- Regards, Carl Ijames carl.ijames at verizon.net

Reply to
Carl Ijames

Somehow, I just don't feel comfortable with anything that will dissolve Tungsten. It might decide to dissolve bits of me, too!

I d>> Ya know, I am a bit skeptical about all this stuff, I went and found a

Reply to
Potblak

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