2 stones 2 different sizes?

[SushiChef22]

Hello,

I own both the 1000 tormek stone and the 4000. Thing is I use the 1000 more alone but want to still use the 4000 sometimes after the 1000. Problem is they are not the same size anymore with the 1000 stone being smaller by a good 15mm. This causes the blade to not sharpen evenly when switching from 1000 to 4000 stones.

What do I do oh great sharpeing gods? Grind the 4000 stone down to match the 1000 stone?

Thanks!

[Stickan]

Hi,
To call things by they right name, I guess you have the SG-250 stone that is a 220 grid stone, but you can use the stonegrader to get about 1000 grid and you got the SJ-250 stone witch is 4000 grid.

Even when your SG-250 get´s smaller you can use the SJ-250, on a knife there will be very little difference on the edge, a tip is to use the marker method so you see that you are sharpening on the edge.

Stig

[Rob]

The way I read your problem is that you're saying if you switch from sharpening your knife (a rough sharpen on the 250-1000 grit stone) you then are expecting to simply replace that with the 4000 Japanese stone and without changing any jig settings, polish finish the same knife?  Is that correct?

In other words, the ideal is that you just leave the knife in the jig, change stones and complete the fine sharpening on the 4000 grit stone.  That's not possible because the size differential between the stones throws out the jig settings?  That's if I understand you correctly.

The answer is that that's bound to happen since one of the variables of the angle setting process is wheel diameter and that is dialled in on the angle master using the purpose built little pointer.  In order to finish any given knife that started being sharpened on the coarser grit stone, you would need to change stones and then reset the anglemaster to reflect the different diameter, then reset the knife in the jig.  As a belt and braces, as Stickan says, you should also test the edge with the marker pen method.

Or....just learn to do the 4000 grit session by hand, free of the jig altogether then you don't need to reset anything :-)

[Herman Trivilino]

What do I do oh great sharpeing gods? Grind the 4000 stone down to match the 1000 stone?

Welcome to the forum SushiChef. I can see the advantage of the 4000-grit (SJ, or Japanese) grindstone for a sushi chef. You are sharpening very hard steel on a daily basis, and you need a sharp, smooth edge. I've been led to believe that this is the ideal grindstone for this job. Never having used one myself, I won't qualify as a sharpening god. 

Grinding down the SJ to match is not a good idea. You'll be wasting a lot of that very expensive grindstone, and assuming you don't alter your sharpening habits, you'll soon be doing it again. And again, and again. In the end you will have wasted more than you've used.

The most economical option is to use the SJ stone more than you currently do. Don't wait for your knives to dull. Sharpen them on the SJ stone even if they're already sharp. If you build the homemade HK-50 jig you could just leave it mounted at all times, and quickly give all your knives a tune up on the SJ stone. The only thing you'd have to do is fill and then empty the water trough each session.

http://forum.tormek.com/index.php?topic=1592.msg6634#msg6634

But to answer your question, when you switch to a grindstone of a different diameter you will need to change the height of the universal support rod using the micro-adjuster, and also change the setting on the Angle Master for the different diameter grindstone. 

[Ken S]

Welcome.

If you sharpen your blade (presumably a kitchen knife) to your desired angle with the SG-250, and then, as Stig suggests, use a black marker on the bevel to set your SJ=250; Before you change the height of the universal support bar, note how many turns and fractions of the micro adjust are necessary to obtain the same angle with your SJ stone. Once you know how much height adjustment is required to match the bevel angle with your slightly different diameter SJ-250, this height adjustment should be a constant (unless the difference in diameter changes).

Once you know this, each time you switch wheels you just dial in the known difference.

If you really want to get efficient, I use a distance from the adjustable stop of the knife jig to the edge of the bevel of 139mm. I have this marked on a piece of plywood.This works with my eight inch chef's knife, my six and eight inch slicers, and my paring knife when mounted in the small knife jig. I have a wooden block with a notch (actually one with 80mm notch for fifteen degree bevel, thirty combined; and another with 86 mm notch for twenty degree bevel, combined bevel of forty degrees). With these very simple jigs, you should not need to use the angle master very much or move your universal support.

Ken

[Herman Trivilino]

At first I was puzzled by what seems to me to be a preference by both Stig and Ken, in this situation and probably others, to use an alternative to the Angle Master. Such as the marker method, counting micro-adjuster turns, or improvising measurement jigs out of a piece of scrap lumber like a carpenter would do when cutting rafters.

But then I realized why perhaps I might find it so much easier to use the Angle Master. It's because of the HK-50! I can use one hand to hold the Angle Master and the other to turn the micro-adjuster. When I get the angle right I lock in the HK-50 platform and off I go.

With the Tormek knife jigs (SVM-45, SVM-00, and SVM-140) one hand is needed to hold the knife in place, one hand is needed to turn the micro-adjuster, and one hand is needed to hold the Angle Master. That leaves you in need of a hand!

[Ken S]

I have no objection to using the Anglemaster. In fact, I use it a lot. My point is that when a similar blade is sharpened, remeasuring seems redundant. When a dozen knives need to be sharpened with the same bevel angle, same projection from the universal support, and same distance from the universal support to the grinding wheel, only one initial measurement is necessary. Just set the distance from the universal support and the grinding wheel first and only once. Then set each knife to the same projection length.

Ken

[Rob]

I'll "yes and" the make it simpler method by suggesting Jeff's old trick and just go through a setup as documented by any of the guys above.  Don't change the knife position in the knife jig but do set the distance of the USB to the Japanese wheel such that it sharpens using the marker method and then make a wooden spacer block that when trapped exactly between wheel and USB allows you to tighten the USB to the exact setting required.

Future sharpenings just require you to change wheels and then use the spacer block to calibrate the position of the USB

[jeffs55]

I do not think that you will benefit from using the 4000 grit stone instead of just using the honing wheel. In use, the 4000 grit does not require the leather honing wheel as a finisher. Just use the honing wheel and see if that does not do it for you. The 1000 grit stone grade and the honing wheel are more than shaving sharp. They will cut any fish that you want in ultra thin slices.

[Ken S]

Jeff, are your thoughts on the SJ-250 4000 grit wheel based on actual first hand use?

Gordon, I hope that after you get your bevel angles matched you will share your results on the forum.

Ken

[jeffs55]

My 4000 grit stone is not made by Tormek as it was purchased before they made one. I have used it on my Tormek. I have two machines, one has the standard gradable stone on it and the other has the 4000 grit one. I have used it and cannot see any appreciable difference in using the 4000 grit stone and using the honing wheel. After all, what is the grit of the honing compound? It is finer than the 1000 grit that you can grade the stone to.

[Herman Trivilino]

I have used it and cannot see any appreciable difference in using the 4000 grit stone and using the honing wheel. After all, what is the grit of the honing compound? It is finer than the 1000 grit that you can grade the stone to.

Right, I think that's the issue. As I understand it, there is a gap between the 1000 grit SG grindstone and the honing compound. When I look at an edge with my 40X microscope I see scratches left by the 1000 grit grindstone. Between the scratches the surface is polished to a mirror finish by the honing wheel.

I haven't tried the SJ grindstone to see if it will remove those scratches, but my guess is that it would. Strange that all of the information available advertises the SJ as desirable but there is no mention of any shortcoming of the SG grindstone, leaving one to wonder just what it is that the SJ can do that the SG can't.

[Ken S]

Very good reply, Jeff. Your thoughts carry more weight being formed from your own experience.

I have been experimenting with using valve grinding compound on the leather honing wheel. I have a second wheel, so as not to contaminate the wheel used with the honing compound. i'm not ready to make any sweeping proclamations, however, initial results indicate promise.

Under ideal conditions, I still prefer the traditional combination of coarse, fine and leather honing wheel. However, if I ever find myself in need of sharpening many chisels quickly, I think I would start with the SG wheel graded coarse; followed by the leather honing wheel with valve grinding compound (hand held). When all were at this point, I would quickly switch leather honing wheels and remove the burr using the honing compound. The valve grinding compound cuts faster; the honing compound leaves a finer finish. This method allows both to work where most effective.

I really can't comment on the SJ-250 4000 grit wheel. I bought one several years ago thinking (correctly) that the price would increase.i have not used it yet.

Ken