Japanese 800 grit wheel is now available from a German seller

[Ken S]

A useful product from a solid manufacturer, purchased through a highly reputable Canadian dealer, with free shipping. Four paws up from Rex!

Add some experience, and you're good to go.

Ken

[Rem]

But do I need it ??    Could this be money better spent on my motorcycle

Send money !!!    R

[Ken S]

You probably don't need it, but at least you can not need it fifty two weeks a year instead of needing something for your motor cycle during the week and a half of Yukon summer.

Ken

[WolfY]

I don't know the prices compared to Tormek and I have the privilege and obligation  to use Tormek original products . I'm just picking from the shelf 

You are right about the importance of sharpening in clean environment. No client or fun sharpening is worth destruction of our health or safety. So water or other arrangements are crucial.

I used the SB same way I did with the SG. As for pressure I think it depends on so many factors that I can't recommend except for starting with only your hand weight pressure and feel the steel reaction.

I believe after some more usage of the SB I will have more conclusions. Will post them of course. But as for now, I will leave it on the machine and use as much as possible. Loved it.

Rem, when saying " I had been trying to sharpen a basic, large kitchen knife all weekend and it just wouldn't do it.", what do you mean? How do you test and why aren't you satisfied with the results or lack of results?
SG stone will sharpen all kitchen knives with ease. Even VG10 and van/moly. I even sharpened D2 and CPM390 on it.

Maybe your sharpening or honing was not complete? Sometime the knife feels sharp and ppl stop sharpening although another pass will make the burr come up and knife will be ready for honing. Some time there is a tiny micro burr left and it makes the knife "dull". Check those situations.

P.S I would buy the SB and sharpen all the bikers D2 and a like knives in order to finance the SB

WolfY

[Ken S]

Go WolfY!

Very good advice.

Ken

[Rem]

Rem, when saying " I had been trying to sharpen a basic, large kitchen knife all weekend and it just wouldn't do it.", what do you mean? How do you test and why aren't you satisfied with the results or lack of results?

Maybe your sharpening or honing was not complete?

WolfY

I had several knives of similar shape and size.  Your basic fairly large kitchen knife.  The others came out just fine after I did my normal routine on them.   This one, after applying about the same amount of time and technique, was still dull.  Just by rubbing my thumb over the edge, I could tell.   I did this twice.  Then I did it a third time for about 3x the time, and it came out OK.   

Two questions at this point:  1. Will having to do this wear down the SG abnormally?   2.  Is there some way to tell if you're dealing with very hard steel, other than how it reacts to the stone?

REMember, I'm ignert, so be gentle.    RR

RR

[grepper]

1.   Will having to do this wear down the SG abnormally?
Basically, No.  It will not wear the stone abnormally.  That is what it is designed to do.

2.   Is there some way to tell if you're dealing with very hard steel, other than how it reacts to the stone?
Basically, No.  You could always get a hardness tester, but they are very expensive.

However, if you know the make/model of the knife a little research may provide the steel type and hardness.  Most kitchen knives seem to be between Rockwell Hardness C (HRC) 55-60.  Knives HRC 60+ such as Shun with SG2 and VG-10 steel are very hard and more difficult to sharpen.

http://forum.tormek.com/index.php?topic=1768.msg8926#msg8926

[Rem]

You're the man, g-man.   Thanks for the response.  Most helpful. 

Maybe I can devise a "RemTest" and calibrate the amount of pain caused when I whack myself in the head with various knife blades. 

I'll figure it out.   Thanks again.    Back to the grind.    R   

[grepper]

r-man,

Check out post #7 here:
http://www.practicalmachinist.com/vb/general-archive/simple-accurate-hardness-tester-80194/

With enough samples and calibration work you might be able to get a reasonably, or at least usefully accurate official Rem scale of hardness.  I'm guessing you don't have a lot of yard work to do these days to consume your time.

For under $100 you can get hardness testing files.  The downside with those things is that you must scratch the surface of your knife and use some sort of scale or weight to assure equal pressure when testing.  I've never tried those and I have my doubts if it would be worth the trouble.  I could of course be mistaken,  (That would be a first!) 

[Jan]

 
Two questions at this point:  1. Will having to do this wear down the SG abnormally?   2.  Is there some way to tell if you're dealing with very hard steel, other than how it reacts to the stone?

Rem, yes, there is a simple method for quick approximate estimation how hard a steel is. It is a set of test files for hardness detection. Usually it contains 6 files at 40, 45, 50, 55, 60, 65 HRC. It is of course not very precise, but you know immediately when you are going to sharpen very hard steel. 

The damage of the blade surface by the test scratch is quite negligible. Just 2 mm long thin scratch.

I have this set but do not use it frequently. Once I was not able to flatten a back of a planer blade, so I tested the steel hardness and found it was more than 60 HRC. It calmed me down and I continued resignedly for another ten minutes of grinding the blade's back on the side of the grindstone.

Jan

[Rem]

Jan and g-man ..... great information.    Thanks so much.   I'm gonna look for one of them there file sets.   I've never heard of such, but then I hadn't heard of poutine until just a little while ago.  I've had a sheltered life.   

Seems a reasonable and (hopefully) inexpensive solution.    Thanks again.   R (-man)

[wootz]

...
CBN wheels are expensive, and a pair of quality whees sized for the Tormek will probably cost more than a new T8. When used with dry grinders, they are typically used in pairs. 80 and 180 grit is a common combination for turning tools. 600 grit, with a back up of 325 is what Tormek uses with its diamond wheels for the T4. I suspect we will soon be wanting 1000 grit and finer. At that point, some of us will lust after multiple Tormeks so we don't have to change wheels.

Suppose we forgot monetary considerations for a moment and are talking of pure perfection.
The most accurate result will be obtained using the same Tormek machine and changing CBN wheels of successive grits.
While the quickest result within good tolerances is obtained using severals Tormeks dedicated to each CBN wheel.
Ideally, one should have a full set of grits from the same CBN wheel maker, so that he won't have to adjust Universal Support as wheels are changed; from the available from the WoodTurners Wonders I would pick #200, #600 and #1200.

I took advantage of the Make Offer button at the WoodTurnersWonders eBay store, and ordered #600 CBN wheel for $225. Allegedly it is purposely made for Tormek T7/8.
Should be close to a finely graded Tormek SG-250 (ANSI #600 corresponds to European 1000 and JIS 800).

If these CBN wheels stand by their claims, switching to them would eliminate the main consumable and in the long run pay back through saving on stones and graders.

Will share impressions in a month or two.

[Rem]

If these CBN wheels stand by their claims, switching to them would eliminate the main consumable and in the long run pay back through saving on stones and graders.

[/quote]

Are the CBN wheels purported to last longer than the equivalent Tormek wheel ??  R

[WolfY]

Will share impressions in a month or two.

Looking forward to it.

[grepper]

First, I don't have, and have never used a CBN wheel.

This topic comes up here every so often.  They sound promising and I have read many reviews, but I have not purchased one simply due to their cost.  There are many reviews and a LOT of information out there, so hop on the 'Net and start researching. 

Search Google for things like:

tormek CNB grinding wheel
how long do CBN wheels last
types of CBN grinding wheels
CBN grinding wheel reviews
CNB grinding wheel durability

Here's what I can summarize from what I have read:

Be sure to get the electroplated version.  You can also use the side of the wheel.  Get the square edged version unless you have a specific need for a rounded edge.

Buy from a reputable dealer in case there are any problems with the manufacturing of the wheel.

Looking FW to wootz's CBN performance review in a month or two.

Pros:

They last a long, long time.   Many reviews saying they many never need to replace it. "Why did I wait so long", that type of thing.  One review spoke of 20%-50% savings over regular grinding wheels in constant duty, high speed grinding operation. Not sure if this was the electroplated version or not.  I would guess the MTBF would be greatly increased in an ultra slow speed application like the Tormek.  Occasional reports of the wheel getting dished in the center.  Not sure if this was the electroplated version or not. Dished wheel replaced under warranty.

Even with high speed grinding they don't get hot.  No need for water.

They are perfectly balanced and flat, and will remain so forever.  No need to ever true the wheel.

Grit remains constant.  No need to dress the wheel.

The diameter of the wheel will never change.  One Kenjig will last forever!

They don't load up, and are non-reactive with steel.

Can be switched for use with both the Tormek and a bench grinder.

Lots of folks use them with the BGM-100.

Cons:

If the wheel is not perfectly in alignment with the control bar of the Tormek, the orientation of the control bar must be changed as the wheel perfectly square and flat and cannot be changed.  While there is no need to ever true the wheel, it is at the same time not possible to do so to match the orientation of the control bar.

In the unlikely event of the wheel surface being damaged to the point of unacceptable performance it cannot be trued.

Unlike the Tormek, multiple wheels must be purchased to vary the grit.

When used with a regular bench grinder, there is the usual environmental air born particulate issue.

Cost.  They are not inexpensive.