Let's talk about sharpness and stones.

[AndrewLee]

The original tormek stone has 220 grit abrasiveness and and be graded to 1000 grit with the dressing g stone. You can further up the grit with the honing wheel and paste. 

Two questions

1. The black silicone stone is advertised as a good way to remove material faster than the original stone, just how much faster and why not use a bench grinder to do that? Cheaper and even tormek recommends doing this (at least for seriously damaged drill bits).

Also, the black silicone stone is graded at 220 grit, same as the original, does that mean it's the composition, not the grit that removes more material?

2. On the other end of the scale,  we have Japanese Waterstones. Its graded at an impressive 4000 grit. Why do we need it that sharp? The stone is not a cheap investment either. Is it really worth bringing your tools up to 4000 grit?

As a general hobbyist, the knives I sharpen are all at 1000 grit and it already "bites" me when I touch the edge. So to me, that's plenty sharp.. Apart from knowing you can make it sharper, why bother? Would a 4000 grit edge last long? I heard of people bring edges up to 10,000 grit and even they claim it goes down to like 6000 grit after a couple of strokes.

[stevebot]

NB. 1000 European is about 700 by American grit standards.
1. It is the harder Silicon Carbide that cuts faster. The binder is the same, and so is the ability to grade fine, which fills the valleys between particles with broken binder.
2. 4000 grit will not be any sharper than a stropped edge but will be less toothy, better for push cuts like shaving and woodworking but not slicing as well as a toothy edge.To obtain the best results you will need to sharpen into the edge (entrance burr) for minimal burr. Not worth it IMHO.
3. Edges go away faster when the angle is smaller or the metal is softer, not because of the grit used. A premium razor blade (BESS 50) will go to BESS 100 after a single cut.
I retract #3. Toothy edges do dull faster than smooth ones.

[Hatchcanyon]

The original tormek stone has 220 grit abrasiveness and and be graded to 1000 grit with the dressing g stone. You can further up the grit with the honing wheel and paste. 

Two questions

1. The black silicone stone is advertised as a good way to remove material faster than the original stone, just how much faster and why not use a bench grinder to do that? Cheaper and even tormek recommends doing this (at least for seriously damaged drill bits).

Also, the black silicone stone is graded at 220 grit, same as the original, does that mean it's the composition, not the grit that removes more material?

2. On the other end of the scale,  we have Japanese Waterstones. Its graded at an impressive 4000 grit. Why do we need it that sharp? The stone is not a cheap investment either. Is it really worth bringing your tools up to 4000 grit?

As a general hobbyist, the knives I sharpen are all at 1000 grit and it already "bites" me when I touch the edge. So to me, that's plenty sharp.. Apart from knowing you can make it sharper, why bother? Would a 4000 grit edge last long? I heard of people bring edges up to 10,000 grit and even they claim it goes down to like 6000 grit after a couple of strokes.

Andrew,

I started as a complete Tormek newbie nearly 3 month ago. The first stone was the standard stone. For plane irons and chisels it worked fine, for the turning tools my wife uses not. These are HSS steel. That was the reason to buy the SB stone too.

In a short time I discovered that the SB is dramatically faster with HSS. It is nearly impossible to grind an oval skew chisel within a reasonable time with the standard stone. The SB does the job 10 times faster (estimated). On the other hand on standard CV steel it is definitely not faster than the standard SG stone. The difference on different steel is coming from the stone composition, not the grit.

I have the SJ stone too but don't use it on all irons. Until now I have polished chisels and plane irons. The finish is fantastic, the sharpness of the iron too. How long the edge lasts is a question of cutting angle, force and most important wood.

No tool ca be too sharp at any time. The keener the edge the longer it will last if the other factors are set right. As far as my experience goes, an edge wotked on the SJ stone will last 2-3 times longer and more important the cuts need less force and they are much cleaner. With a Veritas plane iron polished I can get translucend shaves even from hard European Beech.

Using the SJ stone eliminates using the buffing wheel with the messy honing compound. Another good reason! Ont he downside: Changing the wheel setting the tool a second time.

An optical comparison of the scratches the stones leave on the iron tells me that 220 equals 1.000 on a bench stone, 4000 equals 8.000 or even better.

Some pictures:


Bevel from the standard SG stone, traces of grinding


Polished bevels on Kirschen chisels


Polished back side of a chisel

Conclusion:
Without HSS tools the SG alone is fine, with HSS the SB is a must. The SJ? Sometimes some sort of luxury. But what a result!

Rolf

[Ken S]

Good question, Andrew, and excellent answer, Steve.

Looking at my favorite sharpenng book by Leonard Lee, he recommends stopping at 4000 grit with Japanese water stones. He feels that is quite adequately sharp for the skill level and requirements of most woodworkers. I hold his opinions and experience in high regard. (He likes to keep his readers "out of the clutches of the tool mongers".)

I really believe the majority of Tormek users are very adequately served with just the standard grindstone. I have all three Tormek grindstones, although, in hindsight, my needs are very adequately served with just the SG-250.

I might rephrase your question about higher sharpness with the 4000 grit stone to higher polish. Higher grit stones are really for polishing rather than sharpening. As Steve noted, the "ideal" amount of polish depends on the task at hand.

I would recommend new Tormek users not purchaser either the SB or SJ grinding wheels. Your time and money are better spent in learning the craft. If, after a year of serious sharpening, you feel the need for another grinding wheel, they will still be available and you will be a more experienced shopper.

I am not the person to ask about using Tormek jigs with a dry grinder. It is only "cheaper" if you already have a dry grinder with proper grinding wheels. Comparing a cheap grinder with smaller, narrower wheels is not the same as a Tormek. Besides, I think going through the learning process of reshaping a tool or sharpening a badly damaged drill bit is valuable. Be patient and consider doing it in stages.

If you bevome fluent and consistent sharpening your tools with the SG, stone grader, and leather honing wheel, you will be skilled.

Ken

[RichColvin]

Gentlemen,

I think people look too often at costs in the wrong way.  You can certainly compare the up-front cost of the Tormek vs. stones or even grinding wheels.

But what I would also encourage you to compare are the costs for :

• replacing tools far more often as they get shorter sooner
• the time to get a repeated cutting surface
• having to re-do your work by not using tools that were not sharpened as well as they would have been by the Tormek (i.e., by shortcutting the time req'd to do it using other systems)

Kind regards,
Rich

[Hatchcanyon]

Rich,

I fully agree with you and may only add that using the wrong tool (stone) costs time and time is a valuable thing.

Rolf

[Ken S]

Rob made an interesting remark (in the skew topic of Tormek General) about restoring a skew chisel to full sharpness with one pass. Steve has made a similar comment about knives. Both were using the blackstone. I am not certain about Rob, but I know Steve was using the horizontal position.

Getting beyond the individual tool involved, if we begin with very sharp tools, say 100-175 BESS, and sharpen them before they require more than one pass, say 350-400 BESS, we will always have tools which cut very well. We will need to sharpen more often, but will remove less metal with each sharpening. More importantly, our work will be done with consistently sharper tools.

I realize in the real world this is not always possible. Customers with knives barely off sharp might be reluctant to pay for resharpening. In our heart of hearts, we know we are rarely that diligent. However, it is not a bad ideal to aim for.

In Andrew's world, sharpening drill bits would be much more pleasant that way. Sadly, too many of us remember drill bits abused to the point where the shank end is almost as sharp as the "cutting" end.

More frequent light sharpening has other benefits. It helps us remain fluent with the Tormek and tunes our muscle to very sharp edges.

Ken

[AndrewLee]

When it's for myself I think I'll try to keep my tools are sharp as possible. Tried a bit of woodturning yesterday and have to admit, sharp tools make it so much fun!

Sorry ken, I know Ive been rabbiting on about saving money but I've dipped into my funds meant for buying nice things for the missus and ordered myself the SJ250!

Since I committed myself to getting professionally trained as a tool sharpener, one big question I would ask is whether we should be sharpening customers tools up to 4000 grit. I can't imagine changing the wheels around all the time as being very fun.


Hatchcanyon mentioned that a 4000 grit stone is more like 8000 grit if it's on a wheel. Can anyone care to expand on that? That sound very interesting to me. 

[Ken S]

Andrew,

You must have a VERY understanding wife.

I suggest you write down your questions and ask Robin when you attend his class.

Ken

[AndrewLee]

Firstly she's not my wife, she's a long term live together girlfriend which pretty much means the same thing minus the ring I'm supposed to spend money on (is it just me but I find it hard to justify spending hundreds on a little bit of circular metal?)

Plus I work on two adages

- what she doesn't know won't hurt her.

Failing that:

- it's easier to ask for forgiveness than for permission.

Either way I'm totally dead if she comes into the garage and decides to Google the words tormek plastered all over these machines. I'm even going as far as avoiding the word altogether and saying "a water grinding tool" when I discuss woodworking with her lol


I'm writing down plenty of questions to ask but don't want to completely inundate Robin with a list either.

Besides it's interesting getting responses off the guys here, everyone seems to know alot of indepth stuff when it comes to even the smallest thing sharpening related lol

[Hatchcanyon]

Hatchcanyon mentioned that a 4000 grit stone is more like 8000 grit if it's on a wheel. Can anyone care to expand on that? That sound very interesting to me.

My judgement comes from comparing a bevel polished with a Japanese Bench Waterstone - Cerax 8000 - and bevels worked on the SJ stone.

The second and third picture in the posting above  show a bevel and a backside reflecting a Starrett Combination Square. The irons were polished with the SJ.

Another picture from a plane iron:


I know it is not necessary to hone (Polish) the whole bevel but it is done quite fast and I like the look.

By the way, my irons sharpened on 300 - 1000 - 8000 Waterstones looked never that nice.

Rolf

[Ken S]

Nice work, Rolf.

I suspect the quality of the sharpness and polish of an SJ edge is directly related to the skill of the user with the SG and leather honing wheel.

Ken

[Hatchcanyon]

Ken,

with the SJ stone the leather honing wheel is not used anyway. Polishing the iron is a snap if you use the coloring method for the bevel and modify the polishing angle with the micro adjust accordingly.

Rolf