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BlackbuttWA
1st Aug 2016, 12:02 PM
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G'day ,

Would these be any good for HSS gouges etc. ?


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200mm 8 inch THK Diamond Lapidary Jewelry Grinding wheel 50mm 2" Width Grit 80
Cheers
Col

Pat
1st Aug 2016, 06:11 PM
Col, you mean these (http://www.ebay.com.au/itm/200mm-8-inch-THK-Diamond-Lapidary-Jewelry-Grinding-wheel-50mm-2-Width-Grit-80-/131848390079?hash=item1eb2c6c5bf:g:tVkAAOSwT~9Wlp7m)?

Phily
1st Aug 2016, 07:49 PM
I'm interested on folks thoughts on these as well!!

GeoffW1
1st Aug 2016, 08:31 PM
Hi,

In my experience they are good for final honing to a razor edge, but for roughing to shape or removing big nicks you are better off with a standard oxide wheel.

Cheers

jhovel
1st Aug 2016, 10:07 PM
Diamond wheels are only useful for tungsten carbide tools - apart from their use on other non-metal materials.
For steel (including HSS) tools you need CBN or ceramic wheels (like silicone oxide or carboundum or whatever).
Diamond wheels can only be used on steel at a speed that does NOT produce sparks runnding DRY. And only after establishing that, you should use water or kero or turps as a medium to flush the metal dust off the wheel.
Diamond is carbon - and steel absorbs carbon when heated to high enough temperature. So if the interface gets to a temperature to cause sparks, then the diamond is being absorbed into the sparking metal particles - quite quickly!

Nubsnstubs
1st Aug 2016, 11:35 PM
Diamond wheels are only useful for tungsten carbide tools - apart from their use on other non-metal materials.
For steel (including HSS) tools you need CBN or ceramic wheels (like silicone oxide or carboundum or whatever).
Diamond wheels can only be used on steel at a speed that does NOT produce sparks runnding DRY. And only after establishing that, you should use water or kero or turps as a medium to flush the metal dust off the wheel.
Diamond is carbon - and steel absorbs carbon when heated to high enough temperature. So if the interface gets to a temperature to cause sparks, then the diamond is being absorbed into the sparking metal particles - quite quickly!

Jhovel, that really makes sense to the issue I was having when I was using the lapidary diamond wheels I have. The Thompson bowl gouges I had were getting a sharp edge and excellent burr, but somewhere in the turning endeavor, I would all of a sudden just couldn't get it to cut. I noticed a section of the edge was gone, broken off. I probably lost about a quarter inch sharpening it 5-10 times on each small bowl I was turning. After I got CBN, the edges stopped breaking and would actually cut until dull, unlike when I was using diamond and getting ragged broken edges on the gouge. No one on this side of the pond could explain what the adverse reaction with diamond and HSS would be........ Thanks again for that educated answer.......... Jerry (in Tucson)

Phily
2nd Aug 2016, 06:52 PM
Diamond wheels are only useful for tungsten carbide tools - apart from their use on other non-metal materials.
For steel (including HSS) tools you need CBN or ceramic wheels (like silicone oxide or carboundum or whatever).
Diamond wheels can only be used on steel at a speed that does NOT produce sparks runnding DRY. And only after establishing that, you should use water or kero or turps as a medium to flush the metal dust off the wheel.
Diamond is carbon - and steel absorbs carbon when heated to high enough temperature. So if the interface gets to a temperature to cause sparks, then the diamond is being absorbed into the sparking metal particles - quite quickly!

Great info and advice, many thanks. Can I read into this that by default a diamond wheel could be used effectively on a Tormek?
Cheers
Phil

BlackbuttWA
3rd Aug 2016, 03:21 PM
Thank you all very much for the info. Great reading.
Looks like I will have to save up for some CBN wheels.
Just a tad late:):), but yes Pat they were the ones I was referring to.
Thanks again

Col

NeilS
6th Aug 2016, 12:03 PM
Diamond wheels are only useful for tungsten carbide tools - apart from their use on other non-metal materials.
For steel (including HSS) tools you need CBN or ceramic wheels (like silicone oxide or carboundum or whatever).
Diamond wheels can only be used on steel at a speed that does NOT produce sparks runnding DRY. And only after establishing that, you should use water or kero or turps as a medium to flush the metal dust off the wheel.
Diamond is carbon - and steel absorbs carbon when heated to high enough temperature. So if the interface gets to a temperature to cause sparks, then the diamond is being absorbed into the sparking metal particles - quite quickly!

Well, not in my experience. Perhaps in theory, but after 5 years of using both CBN and diamond wheels I cannot say that I have noticed any significant loss of diamond off the wheel I'm using (a Woodriver).

See a recent update on my thread about that here (http://www.woodworkforums.com/f8/diamond-cbn-grinding-wheels-147502#post1965552).

I rarely raise a spark while dry grinding on the diamond wheel and I prefer the finish I get off it.

Based on my experience, I would not hesitate to go with another diamond wheel as my preferred sharpening abrasive for my woodturning tools, although, as I have said in that other thread, "At the rate I'm using it, this diamond wheel is not about to wear out any time soon!.

Of course, I don't know about the quality of the diamond wheel you are looking at Col. From what I can see of the link provided by Pat, it appears that the diamond is sintered onto the wheel in the same way that most CBN wheels are constructed. My Woodriver has the diamond set in a bonded matrix, so may perform differently. It does seem very cheap, but price doesn't always indicate quality.

If I could only afford a CBN or diamond wheel, and had, or was likely to have, carbide tools (tips) to sharpen then diamond is the way I would go.

Col, should you decide to take a chance on the THK diamond wheel please let us know how it performs.

Yanis
7th Aug 2016, 12:17 PM
I have to side with NeilS here. I swapped to diamond for sharpening chain saws a few years ago and never looked back. I cut a LOT of wood using my 3 chain saws and they work a treat. And I get sparks whenever I sharpen with them.

John