First Post: follow-up stone from DF-250

[SimonJonas]

Hello,
this is my first post here, glad i found this forum.
I want to buy a T-8 and think about getting the black 50th anniversary edition with the df-250 diamond wheel. I do realize that the standard SG-250 is a more versatile stone, but I'm still tempted by the 50 year warranty, the composite honing wheel and the diamond stone in the black edition.
My question is:
if I want a really refined surface on my tools and knives, would i need to get a DE-250 as a follow up to the DF, or could i directly go from DF-250 to the SJ-250, which is around 4000grit?
Any input would be much appreciated.
Cheers-Simon

[Thy Will Be Done]

Hello,
this is my first post here, glad i found this forum.
I want to buy a T-8 and think about getting the black 50th anniversary edition with the df-250 diamond wheel. I do realize that the standard SG-250 is a more versatile stone, but I'm still tempted by the 50 year warranty, the composite honing wheel and the diamond stone in the black edition.
My question is:
if I want a really refined surface on my tools and knives, would i need to get a DE-250 as a follow up to the DF, or could i directly go from DF-250 to the SJ-250, which is around 4000grit?
Any input would be much appreciated.
Cheers-Simon

If you're new to the Tormek I would suggest starting on the SG-250 as it will be much more forgiving of mistakes which are inevitable and actually it's a great stone to work on for most common steels.  The downside is you'll have to a true it often to recut the surface to keep it cutting aggressively and flat/precise surface.

Follow up stone all depends on what you are sharpening and what you are using that tool for exactly.  Even just saying it will sharpen knives means little as you can do different types of cutting, etc.  Using a 4000 grit stone after the diamond stone could either increase or decrease actual performance.  If you're primarily push cutting (no slicing motion or draw but cut like a chisel) then you'll be best served with 4K.

[John Hancock Sr]

could i directly go from DF-250 to the SJ-250, which is around 4000grit?

Probably not. The DF-250 is 600 and the SJ-250 being 4k is too big a jump. You definitely needs something about 1200-2000 as an intermediate step. After the SJ-250 you will find grooves from the 600 that are difficult to remove. The whole point of the SJ is to polish from the extra fine grit. As Thy... says the SG is a far better starting position since you can go to 1000 which is a better transition. Yu will still find scratches but they will be far fewer and smaller.

Also, it depends on what you are sharpening and what you are trying to achieve.

[tgbto]

The DF-250 is not nearly fine enough that the SJ would be able to mirror polish it. You would get a smooth edge with nice scratch marks.

The SG has a much more homogeneous scratch pattern, especially when graded fine.

As a side note, the Tormek in general is not primarily a knife sharpening device. It does it quite well though, after a learning curve and the acceptance of a few pitfalls. The Black edition in my opinion is even more tilted towards (hard steel-/carbide-) tools sharpening,and much less forgiving. I think you'd be better off with a standard T-8, a USB-430 and a MB-102 if you intend to sharpen knives.

I ordered the SJ along with my T-8 because I loved to polish edges. Now I seldom use it because :
- The finish after SG+leather wheel honing at a controlled angle is quite polished already
- I found that knives finished with a SJ actually end up with lower edge retention when it comes to standard kitchen tasks.
- The claim that you don't have to hone a knife after a final pass with the SJ does not stand a reality check.

[SimonJonas]

Thanks to everyone for your answers! You helped me a great deal. I'll be sharpening mostly bushcraft knives for carving purposes (3 of the knives are Fällknivens, so they come with a convex edge).
I'll also sharpen my carving tools with the Tormek. They're all Svante Djärv knives made from carbon steel. Some carving knives, drawknife as well as a carving axe. Also some spoon carving knives, but i guess those can't be sharpened with the Tormek.

[tgbto]

Based on what you're saying, a DF wheel should be more of a burden than a blessing (mandatory use of ACC, at least a DE wheel in addition, and still the SJ if you want to polish.

Also some spoon carving knives, but i guess those can't be sharpened with the Tormek.

You might want to look at this video with Wolfgang. I have never sharpened such a tool, and it might require a lot of practice. Wolfgang has a tendency to make complex things look easy thanks to his level of mastery and feeling. The SVM-00 in itself requires quite a bit of experience and training, so ...

[SimonJonas]

Based on what you're saying, a DF wheel should be more of a burden than a blessing (mandatory use of ACC, at least a DE wheel in addition, and still the SJ if you want to polish.

Also some spoon carving knives, but i guess those can't be sharpened with the Tormek.

You might want to look at this video with Wolfgang. I have never sharpened such a tool, and it might require a lot of practice. Wolfgang has a tendency to make complex things look easy thanks to his level of mastery and feeling. The SVM-00 in itself requires quite a bit of experience and training, so ...

Thank you so much for posting this link, I've never seen it. Looks possible but certainly not easy to me!
As for the wheel, I'm almost certain I'll get the normal version of the T-8, just seems more suited to my needs.

[Ken S]

The T8 Black is an excellent machine. It gets its excellence because it is a T8 blue with a black finish. I am not knocking esthetics, collectibility, or a fifty year warranty. I am just saying that a solid machine is a solid machine regardless of color. On the plus side, I do believe the limited black edition will probably retain a slightly higher resale value because it is a "special edition".

I suspect our opinions are influenced by marketing or how we interpret it. "mandatory use of ACC". Use of ACC is not mandated by Tormek. It is recommended with good reason. It helps keep the surface of the grinding wheel clean and helps prevent clogging. The marketers who bemoan "messy water" and "expensive ACC" seem to forget the hassle of dust. They also ignore the reason for using ACC to protect a thousand dollar investment in a set of super abrasive wheels.

All six of Tormek's grinding wheels have both pros and cons. For many years the SG served us well as the only wheel. As steels got harder, we thought we had to have a faster cutting silicon carbide wheel. And, we wanted a 4000 grit wheel for polish. (I remember when one member wanted an 8000 grit wheel, another example of bench stone thinking/marketing.)

We have been marketed to dread the change in wheel diameter due to use, as well as the occasional need for wheel truing. Progress? Probably, but well seasoned with marketing hype. Is the stone grader a perfect concept? I doubt it, but are really that much better off to pay four hundred dollars more to add two more wheels of different grits?

A DF wheel is a balance between fast cutting and smooth finish. Ideally, we should have the full set of three diamond wheels. Would the added benefits equal the added cost?

I agree with the Tormek instructors that most beginners are best served with the SG grinding wheel. For many of us, it is the only grinding wheel we will ever need. I can also see the allure of the limited edition for those who like to collect things.

Ken

[tgbto]

I suspect our opinions are influenced by marketing or how we interpret it. "mandatory use of ACC". Use of ACC is not mandated by Tormek. It is recommended with good reason. It helps keep the surface of the grinding wheel clean and helps prevent clogging.

I don't know if that's marketing influence, but the way I read the following excerpt from Tormek website, the use of ACC is mandatory to prevent rust formation when using water and using water is recommended but not mandatory :

Rust protection for increased service life

All diamond grinding wheels are supplied with 150 ml of ACC-150 Anti-Corrosion Concentrate. Always add the concentrate to the water when sharpening with water to prevent rust on the grinding wheel. Add 10 ml (0.02 pints) of concentrate to 250 ml (0.4 pints) of water (~4%). We recommend always using water when sharpening with diamond grinding wheels if possible, as it both prolongs the service life of the wheel and provides a smoother sharpening surface. You can also sharpen without water.

or on another page of the website :

When the diamond layer is touched by the swarf from your tool, pores will be created in the nickel coating, exposing the steel core. Therefore, always use the ACC-150 Anti-Corrosion Concentrate in the water when sharpening with water to prevent rust on the grinding wheel.

You cannot view this attachment.

As the OP wanted to sharpen to a polished edge, I don't see it happening without water - dust notwithstanding - so ACC is to be added.

As you pointed out, Ken, one of Tormeks' key advantage is water cooled sharpening. So...

[Ken S]

TGB,

I agree. They are not always totally firm in recommending ACC, but they should be. I have never seen a Tormek person sharpen without ACC, nor have I seen any Tormek videos about scrubbing the wheels. I have seen two videos about scrubbing CBN wheels, one by a vendor.

Ken

[tgbto]

Might be yet another lapse in english on my part, but "always use ACC" on every webpage and in the sharpening handbook seems pretty firm a recommendation to me. Kinda what I'd call mandating it.

[Ken S]

Might be yet another lapse in english on my part, but "always use ACC" on every webpage and in the sharpening handbook seems pretty firm a recommendation to me. Kinda what I'd call mandating it.

Your post reminds me of a line from "My Fair Lady". "Her English is too good, he said, that clearly indicates that she is foreign!"

Ken

[tgbto]

Ahahah. Thanks ... I guess

[cbwx34]

Might be yet another lapse in english on my part, but "always use ACC" on every webpage and in the sharpening handbook seems pretty firm a recommendation to me. Kinda what I'd call mandating it.

Yup...

[Thy Will Be Done]

If you are really set on getting a refined edge along the lines of the 4000 wheel, then adding a stone like the Sun Tiger 800 after the SG-250 would be highly recommended as an intermediate step.  The 4000 cuts very slowly and loads very quickly so does not grind quickly.  As others have mentioned you can simply grade the SG-250 on the fine side of the stone grader to get a similar finish on the edge to help make the jump to 4000 wheel. 

Otherwise you'll be at it a long time trying to remove deep scratches from the SG-250.  If you don't mind having scratches mixed in the surface with the polish then you don't technically need any stone between but this would serve to remove the scratches only prior to 4000.  If you are only interested in actually polishing the apex and do not care about looks, then jumping to the 4000 wheel using micro-bevel is best.

Also, Sun Tiger does offer 4000 grit stone as well but it's not a direct replacement for the Tormek 4000 from what I can tell.  It is in fact much cheaper but that may or may not mean it is of lower quality as it does come from a well respected Japanese stone manufacturer (Matsunaga) which produces the King Deluxe line of stones which are just about the industry standard for Japanese waterstones.

One thing that hasn't been mentioned which is worth noting is the difference in how plated abrasives like the Diamond wheels cut compared to bonded abrasives in the stone wheels.  There is a single layer of diamond plating which means they will cut far more coarse than a wheel of the same grit that is produced as a traditional stone that is bonded like the SG-250.  They are also MUCH easier to damage with errors of too much pressure, angle, etc.