After truing the SJ stone

[Grizz]

I have a question for some of you... what is the "wear rate" of the SJ stone, compared to your SG stone?

I've had good success maintaining the stone solely with a fine rust eraser... and the stone shows very little wear as a result.  I think of this stone like any other fine waterstone... it should last a very long time.  I know some of you sharpen a lot more than me... but your "wear rate" just seems high to me.  (My opinion... and why I'm asking.)... 

Tormek says about this stone... "Its unique composition gives this stone an extremely long life".  I wish Tormek would publish some "actual use" numbers... but doubt we'll see that.

Anyway, am curious what the comparison might be.

I find that the SJ gets out of round somehow and I cant figure out why. I always use light pressure and always a side to side motion. it seems as tho I have to true it after about 7-8 knives. mostly Wustoff and Henckels. But, when I re-true it, it is out by less than 2mm. it would only get worse from there on, so I go ahead and true it when I notice it. I have been using the new SJ since march and I am at 241 wheel diameter, so I have used 9 mm so far. I did hone up a few drill bits, but I don't do that anymore. maybe that's where I got the most wear. overall I am happy with the SJ and it does an excellent job. no complaints.

[Sharpco]

I have a question for some of you... what is the "wear rate" of the SJ stone, compared to your SG stone?

I've had good success maintaining the stone solely with a fine rust eraser... and the stone shows very little wear as a result.  I think of this stone like any other fine waterstone... it should last a very long time.  I know some of you sharpen a lot more than me... but your "wear rate" just seems high to me.  (My opinion... and why I'm asking.)... 

Tormek says about this stone... "Its unique composition gives this stone an extremely long life".  I wish Tormek would publish some "actual use" numbers... but doubt we'll see that.

Anyway, am curious what the comparison might be.

I agree.

I feel that the life of SJ is much longer than SG.

[cbwx34]

I find that the SJ gets out of round somehow and I cant figure out why. I always use light pressure and always a side to side motion. it seems as tho I have to true it after about 7-8 knives. mostly Wustoff and Henckels. But, when I re-true it, it is out by less than 2mm. it would only get worse from there on, so I go ahead and true it when I notice it. I have been using the new SJ since march and I am at 241 wheel diameter, so I have used 9 mm so far. I did hone up a few drill bits, but I don't do that anymore. maybe that's where I got the most wear. overall I am happy with the SJ and it does an excellent job. no complaints.

Thanks for the reply.

I'm trying to get a little perspective here... in relation to a fine waterstone (sharpening by hand).  Here's my train of thought... maybe I'm off base.

A waterstone is around 8"x3"(x3/4")  or 24sq.in of surface.

A 250mm wheel is about 31" circumference... so around 62sq.in. of surface... essentially 2 1/2 times a waterstone?

I've had some finer waterstones for years... that I've only taken a few mm off... and they've seen a lot of use.

In 3 months... you've used 9mm of wheel... essentially, if I done the math right... you've used an entire waterstone in 3 months?

For a grinding stone, I could see the possibility... for a finishing stone... that just seems high... unless I'm not thinking about this correctly?

Even from a practical standpoint, (no math haha)... 9mm of stone seems a lot.  That's why I'm wondering how it relates to other stones you use?

(I guess, based on my waterstone experience... I would have expected the SJ wheel to outlive me).

My one thought, somewhat related, is maybe it's too big a "leap" from the SG wheel to the SJ... requiring it to be used more than normal... especially if trying to "polish out" all the scratches?  I usually use it enough to refine the edge... but not really striving for a "mirror" type finish.

Other thoughts/ideas?

[Grizz]

CB, I do recall sharpening a double edge home made knife for a customer and spending a lot of extra time on it trying to remove a lot of his scratches during his manufacture process. I remember thinking to myself, boy, i'll never do another one of them !. so that probably used up a lot of my stone !

[wootz]

Wow Wootz, I just learned a lot from that paragraph. I have chipped the inside edge before. I will try the 1000 diamond to clean the SJ. I am assuming the plate in the jig goes over the top of the 1000 to give it support.

Yes Grizz, the plane iron is to support the diamond plate - these diamond plates are 1mm thick, the cheapest, and they must be that.
Never use your expensive DMT diamond plate to grade the wheel, as the wheel does wear the diamond layer.

I've tried a range of diamond grits on Tormek wheels, and the best are:
- to grade the regular SG from coarse to fine I use #400 diamond plate, sometimes followed by #1000;
- for the Japanese SJ use #1000 (not finer). With the Japanese it is important not to press the diamond plate edge to the wheel or you will chip its edges - you can see in my video how to position it properly https://youtu.be/UckPmizllk0 - skip to the minute 5-6 - the plate contacts the wheel with its surface and not the end.

Using them in the square jig ensures your wheel stays square after grading/declogging. In comparison, when I had been using the grading stone on SG and Nagura on SJ, they would go out of square pretty soon.


PS finishing your FVB today, will email when ready

[Sharpco]

Wow Wootz, I just learned a lot from that paragraph. I have chipped the inside edge before. I will try the 1000 diamond to clean the SJ. I am assuming the plate in the jig goes over the top of the 1000 to give it support.

Yes Grizz, the plane iron is to support the diamond plate - these diamond plates are 1mm thick, the cheapest, and they must be that.
Never use your expensive DMT diamond plate to grade the wheel.

I've tried a range of diamond grits on Tormek wheels, and the best are:
- to grade the regular SG from coarse to fine I use #400 diamond plate, sometimes followed by #1000;
- for the Japanese SJ #1000. With the Japanese it is important not to press the diamond plate edge to the wheel or you will chip its edges - you can see in my video how to position it properly https://youtu.be/UckPmizllk0 - skip to the minute 5-6

Using them in the square jig ensures your wheel stays square after grading/declogging.

Can Diamond Plate be used on SB-250?

[wootz]

Yes SHARPCO, but only the diamond plate #400 and not any finer - I mean I tried finer grits in the past to no good.

[Ken S]

Wow Wootz, I just learned a lot from that paragraph. I have chipped the inside edge before. I will try the 1000 diamond to clean the SJ. I am assuming the plate in the jig goes over the top of the 1000 to give it support.

Yes Grizz, the plane iron is to support the diamond plate - these diamond plates are 1mm thick, the cheapest, and they must be that.
Never use your expensive DMT diamond plate to grade the wheel, as the wheel does wear the diamond layer.

I've tried a range of diamond grits on Tormek wheels, and the best are:
- to grade the regular SG from coarse to fine I use #400 diamond plate, sometimes followed by #1000;
- for the Japanese SJ use #1000 (not finer). With the Japanese it is important not to press the diamond plate edge to the wheel or you will chip its edges - you can see in my video how to position it properly https://youtu.be/UckPmizllk0 - skip to the minute 5-6 - the plate contacts the wheel with its surface and not the end.

Using them in the square jig ensures your wheel stays square after grading/declogging. In comparison, when I had been using the grading stone on SG and Nagura on SJ, they would go out of square pretty soon.


PS finishing your FVB today, will email when ready

Wootz,

I have been watching every online Tormek and sharpening related video I can find for several years. Yours is among a very small number I would call outstanding. You show the true potential of what the Tormek can do in skilled hands. Your video is my favorite kind, no cutesy background music or video tricks; plenty of solid and accurate information; and a presenter who does not fumble with the EZYlock. You show what can be done with essentially an all Tormek set up and support it with a very impressive BESS reading.

Keep up the good work!

Ken

[Grizz]

yes Ken, Wootz definitely has a slow soft touch for his technique ! Great job Wootz.