Blackstone Wheel

[Thy Will Be Done]

I'm beginning to really think I need this stone to add with the standard that came with the T8.  I've used this for quite some time and really found that while I don't grind much if any High Speed Steel, the standard stone can be quite slow especially on tougher steels that have low grindability as the edge bevel width gets wider.  Anybody else here using this Blackstone have anything to report before I take the plunge.  It's costly enough that I don't want to regret getting it but I can't see myself being anything but delighted to work more efficiently to produce my work.

[RichColvin]

I have all 6 grindstones. What are you trying to sharpen?

[tgbto]

I'm beginning to really think I need this stone to add with the standard that came with the T8. 
<snip>
the standard stone can be quite slow especially on tougher steels that have low grindability as the edge bevel width gets wider.

The SB-250 does not offer faster steel removal on ordinary carbon steel. The Tormek Blackstone Silicon can also touch up tungsten carbide. The grit size is the same 220 as the original Tormek SG-250 stone. Thanks to its sharp and relatively small grains, the Blackstone removes hard steel efficiently even at low grinding pressure.

In their dedicated video, they demo it with what appear like standard carbon knives, a ceramic knife, ...

They even mention it is for "turning tools and machine planer blades" and it "leaves a really nice finish for knives sharpening" in this video, where they also mentioned it was kind of "before they had the diamond stones" the diamond stones. Although in another one they mention the pros being that you can round the corners, grade it to change the grit, and the cons being that you need to true it, and it is eventually more versatile than the diamonds.



So I guess it comes down to when an alloy is deemed "exotic" or "out of the ordinary". I personally keep the SB for HSS bits, as I found marginal improvement even with HRC 63 carbon or stainless steels, and I prefer the SG feedback. So ... the SB doesn't see much use, but drilling with DBS-sharpened bit is a delight.

[Thy Will Be Done]

I have all 6 grindstones. What are you trying to sharpen?

I don't believe it's so much the steels I am grinding being the problem but moreso the fact that the knives are heavily overbuilt outdoor knives that customers send me and the edges are very thick behind the edge from the factory.  This means that early on in the process of reprofiling to a lower edge angle the stone cuts freely but as the bevel width gets wider and closer to being finished the grinding stalls to the point of seeming to barely proceed without using excess pressure.  Therefore it does seem that the Blackstone would keep cutting when the standard stone has stalled, according to their literature on the website.

[RichColvin]

You should watch the YouTube videos from Tormek.  They address this. 

[tgbto]

I'd try using frequent regradings of the SG stone to a rough grit.

When I have some heavy lifting to do with the T-8, I usually put a second USB in the horizontal position, with a SE-77 mounted with a 160 diamond plate ready to slide on. I change the USB distance to stone to avoid using only a tiny part of the plate, or move the plate in the SE-77.

[Ken S]

I have always felt that the SB-250 has been the overlooked other child of the Tormek grinding wheels. The SB was introduced around 2009 at the the same time as the 4000 grit SJ Japanese wheel. The two shared only one paragraph in the handbook and had very limited product video coverage. Of the two, the SJ has always been the glamour choice. Beginners who had hardly mastered the SG clamored to purchase the SJ, even though it was the most expensive accessory in the Tormek lineup.

The SJ has been touted in the online classes as the wheel to give knives "that extra love" of a high polish finish. There is nothing wrong with this; however, while the extra love polishing stone grabbed the best of show headlines, the workhorse SB was overlooked.

As seen in forum posts years ago, the SB had problems with glazing. I'm not sure how much of this was due to design problems and how much was due to poor technique (using too much grinding pressure). Several posts mentioned poor performance in sharpening thickness planer blades, admittedly among the more challenging tools to sharpen. I believe many users, including me, put the SB back in the box on the shelf.

The SB has had a few notable advocates, perhaps the most notable being knife expert Steve Bottorff. Steve, who has worn out many grinding wheels over the years, switched to the SB because it lasted longer.

The SJ remains the extra love glamour wheel. The new glamour choices in the workhorse category seem to be the diamond wheels, with the SB being overlooked. Even hss woodturning tool sharpening and reshaping, a logical choice for the SB, has been overshadowed by the diamond wheels.

I was encouraged to see the late Wootz mention the SB very favorably in one of his last videos. He paired the SB with the new composite polishing wheel. I believe this combination has a lot of potential. I also like Wootz' idea of dressing the SB with a diamond stone. The coarse side of my stone grader became glazed by the SB. As I said, I believe the problem may actually be in the technique rather than the product. I would like to see the SB finally receive more extensive coverage in the videos and more than half a paragraph in the handbook.

Ken

[tgbto]

I also like Wootz' idea of dressing the SB with a diamond stone.

This is clearly one of the (many) excellent ideas in Wootz's videos. It works a treat for SB, SG and SJ alike, with the proper grit obviously

The coarse side of my stone grader became glazed by the SB.

I think Wolfgang now mostly demonstrates using the edge of the SP and not the flat for coarse grading. It increases the efficiency a lot (although at the expense of control, so probably a bit more frequent truing).

[Ken S]

We are thinking along the same lines. Borrowing the idea from Wootz, I purchased a set of three DMT diamond file cards, one each of three different grits. At the time, I recall the set costing around $25 USD, not much more than Wootz' "cheapest available" and DMT quality. I purchased a piece of aluminum 2' x 2" x 1/16" and cut it into three equal 8" lengths. I epoxied one of the diamond cards to each length. This arrangement was considerably less expensive than using a plane blade and was easier to clamp. These will eventually wear out. I consider them medium term consumibles.

Through personal communication with Tormek, I have become aware that Tormek technique has evolved since the handbook was written. These advances have largely remained in Sweden. Tormek is not intentionally secretive; they just lacked an efficient way to share this information en masse. Culturally, videos have become the preferred method of learning. Covid forced Tormek to cancel attending shows and start the online video classes. They have been invaluable learning tools. Using the edges of the stone grader is an example of the subtle improvements shown in the online classes. I hope we can combine perhaps a dozen of these simple improvements into our daily work habits. I believe these simple changes would substantially diminish many of our difficulties.

As a retiree, my schedule generally permits me to participate in the live classes. I try to carefully prepare topic appropriate questions. Wolfgang, Sebastien, and the other presenters have been quite good about answering these questions. Included have been the T4 "thirty minute" myth; using water with the T1 composite honing wheel; and the effect of varying the amount of swing with the SVD-186R. They have even included questions I previously emailed to them. They have really done a fine job of interacting.

I encourage our members to do the same thing. If, quite understandably, work schedules conflict with participating in the live presentation, email support (support@tormek.se) and ask support to forward your questions to Sebastien or Wolfgang. Tormek makes these classes to benefit us Tormek users. Let's maximize their benefits.

Ken

[Thy Will Be Done]

I have always felt that the SB-250 has been the overlooked other child of the Tormek grinding wheels. The SB was introduced around 2009 at the the same time as the 4000 grit SJ Japanese wheel. The two shared only one paragraph in the handbook and had very limited product video coverage. Of the two, the SJ has always been the glamour choice. Beginners who had hardly mastered the SG clamored to purchase the SJ, even though it was the most expensive accessory in the Tormek lineup.

The SJ has been touted in the online classes as the wheel to give knives "that extra love" of a high polish finish. There is nothing wrong with this; however, while the extra love polishing stone grabbed the best of show headlines, the workhorse SB was overlooked.

As seen in forum posts years ago, the SB had problems with glazing. I'm not sure how much of this was due to design problems and how much was due to poor technique (using too much grinding pressure). Several posts mentioned poor performance in sharpening thickness planer blades, admittedly among the more challenging tools to sharpen. I believe many users, including me, put the SB back in the box on the shelf.

The SB has had a few notable advocates, perhaps the most notable being knife expert Steve Bottorff. Steve, who has worn out many grinding wheels over the years, switched to the SB because it lasted longer.

The SJ remains the extra love glamour wheel. The new glamour choices in the workhorse category seem to be the diamond wheels, with the SB being overlooked. Even hss woodturning tool sharpening and reshaping, a logical choice for the SB, has been overshadowed by the diamond wheels.

I was encouraged to see the late Wootz mention the SB very favorably in one of his last videos. He paired the SB with the new composite polishing wheel. I believe this combination has a lot of potential. I also like Wootz' idea of dressing the SB with a diamond stone. The coarse side of my stone grader became glazed by the SB. As I said, I believe the problem may actually be in the technique rather than the product. I would like to see the SB finally receive more extensive coverage in the videos and more than half a paragraph in the handbook.

Ken

I will likely get one and use it extensively.  I am torn between this and the Sun Tiger 800 at the moment which will be the next purchase as I cannot get both currently.  You have given me quite a bit of good info here to justify giving it a try.

[Thy Will Be Done]

I also like Wootz' idea of dressing the SB with a diamond stone.

This is clearly one of the (many) excellent ideas in Wootz's videos. It works a treat for SB, SG and SJ alike, with the proper grit obviously

The coarse side of my stone grader became glazed by the SB.

I think Wolfgang now mostly demonstrates using the edge of the SP and not the flat for coarse grading. It increases the efficiency a lot (although at the expense of control, so probably a bit more frequent truing).

I have heard Wolfgang say that the reason is if you use the flat of the grading stone then you will actually glaze over the grinding wheel surface.  This has been my experience as well and it wasn't until he said this that I was able to confirm my suspicions.  I now use the corner and get a much more aggressive cutting stone.  I actually feel the truing tool works best to resurface because, diamonds.  I don't know how much stone this wastes if you do a very light pass with it cutting very shallow. 

[Ken S]

"I will likely get one and use it extensively.  I am torn between this and the Sun Tiger 800 at the moment which will be the next purchase as I cannot get both currently.  You have given me quite a bit of good info here to justify giving it a try."

What do we know about the Sun Tiger 800? 800 grit. The SG is made of aluminum oxide; the SB is made of silicon carbide, designed to cut harder alloys and cut more quickly. I did a quick Internet search on the Sun Tiger, and could not find the material. You should know the material of a grinding wheel as well as the grit.

I am not saying anything negative about the Sun Tiger wheel, only suggesting that you might want to learn more before investing that much.

Ken

[Thy Will Be Done]

"I will likely get one and use it extensively.  I am torn between this and the Sun Tiger 800 at the moment which will be the next purchase as I cannot get both currently.  You have given me quite a bit of good info here to justify giving it a try."

What do we know about the Sun Tiger 800? 800 grit. The SG is made of aluminum oxide; the SB is made of silicon carbide, designed to cut harder alloys and cut more quickly. I did a quick Internet search on the Sun Tiger, and could not find the material. You should know the material of a grinding wheel as well as the grit.

I am not saying anything negative about the Sun Tiger wheel, only suggesting that you might want to learn more before investing that much.

Ken

Vadim said the Sun Tiger worked up to a certain point which makes me believe it's Aluminum Oxide.  I don't do a lot of high vanadium steels so it should work well enough.  I really struggle to believe Tormek has not pulled their heads from the sand to realize that they really need an ACTUAL 1000 grit stone and not the glazed over version of a worn 220 that more burnishes than cuts.  I actually would and prefer to finish grind the apex by raising one degree and using the standard 220 than fatigue the steel at the apex by burnishing. 

Here's the link where I found it, can't find any dealers in America selling this stone.  It's the top stone, the brown color almost guarantees my guess is correct.

https://www.fine-tools.com/Tormek.html

[Ken S]

TWBD,

Your observation that the Sun Tiger is probably aluminum oxide is very astute. I agree. I wish you could have been with me during the weekend woodworking show when Stig Reitan was demonstrating for Tormek. Stig is a master with the Tormek. He has always sung the praises of the SG and the stone grader. He does not have glazed stone grader problems. Using the traditional Tormek technique, SG graded coarse, SG graded fine, and leather honing wheel with PA-70 honing compound, Stig consistently gets very sharp edges.

I remember when Vadim started using the Sun Tiger wheel. I believe he may have been influenced by Ionut, one of our most innovative former members. Being also influenced, I also purchased one. I used it for a while, but decided that I preferred my SG.

I think the stone grader is a good tool with the SG. I am less convinced with the SB. One of Vadim's last videos shared his thoughts about the composite honing wheel. He liked the combination of the SB graded coarse with the TT-50 and the composite honing wheel. I think that combination would give you faster cutting.

Keep us posted.

Ken

Here is a link to of my favorite Vadim videos which fits into this conversation.

https://youtu.be/tVTg0HVgoKo

[Thy Will Be Done]

TWBD,

Your observation that the Sun Tiger is probably aluminum oxide is very astute. I agree. I wish you could have been with me during the weekend woodworking show when Stig Reitan was demonstrating for Tormek. Stig is a master with the Tormek. He has always sung the praises of the SG and the stone grader. He does not have glazed stone grader problems. Using the traditional Tormek technique, SG graded coarse, SG graded fine, and leather honing wheel with PA-70 honing compound, Stig consistently gets very sharp edges.

I remember when Vadim started using the Sun Tiger wheel. I believe he may have been influenced by Ionut, one of our most innovative former members. Being also influenced, I also purchased one. I used it for a while, but decided that I preferred my SG.

I think the stone grader is a good tool with the SG. I am less convinced with the SB. One of Vadim's last videos shared his thoughts about the composite honing wheel. He liked the combination of the SB graded coarse with the TT-50 and the composite honing wheel. I think that combination would give you faster cutting.

Keep us posted.

Ken

Here is a link to of my favorite Vadim videos which fits into this conversation.

https://youtu.be/tVTg0HVgoKo

The problem is not a matter of getting consistently sharp edges but ones that remain undamaged in a way that they retain sharpness quite well.  I can get consistently sharp edges straight off the 220 that will shave arm have and are burr free by simply raising the angle 1 degree and turning the wheel by hand alternating sides with very light passes for a couple minutes.  It does not take a very fine abrasive to get a sharp edge that is burr free but it helps. 

What the 1000 grit waterstone does allow for is less damage at the apex than the 220 grit creates while still allowing acceptable removal rate to be a serious stone for just sharpening a dull edge.  In my view, 220 is a shaping stone or possibly finishing if you need a good aggressive slicing edge that retains it's edge a long time.  1000 would be ideal for something that will get finished at 3000 or up or just to get the edge thin enough to where it's ready for a final ape.

So what I've worked out to date is that the SG stone works fine with most of the steels I've ground up until the bevel gets very wide after reprofiling a knife from say 25 DPS down to 12-15 DPS.  This is where it stalls in the finishing stages of shaping and the SB would be ideal for me.  Once I've finished or gotten close to finished I'd like to switch to the 1000 for cleaning up the apex damage prior to setting an apex.