Stone activation with the grader

[Rob]

This is picking up on the thread on planar blade sharpening but is more generic so figured here is the appropriate place

Jeff you advised activating the SG using the corner of the grader because that's more aggressive. I entirely understand that and have always done it ever since watching your DVD for turners

One minor detail occurred to me as I was blasting into my SG during my planar sharpening.  My corners on the grader have all worn smooth some time ago. Is there any cutting tool you know of that can kind of reactivate the re activator? (If you know what I mean)

I'm thinking is there some way to get corners back in the 220 side of the grader or does that not matter? 

Many thanks in advance

R

[Jeff Farris]

Personally, I think a brand new grader is not very valuable. The corners on the coarse side are too sharp and the curve of the grindstone isn't cut into the smooth side. I like them broken in, where the corner of the coarse side is a bit rounded over and I've got a nice matching curve cut in the smooth side.

[Herman Trivilino]

I'm glad to hear that about the grader.  I was concerned that I had not broken mine in properly because of the curve on the smooth side.  And my grandson once used the coarse side to try and sharpen an axe!  He had done a good job of glazing it over by the time I caught him.

And while were on the subject there's something else I wanted to ask about.  I can't ever seem to get my grindstone dressed properly using the fine side of the grader.  You've mentioned several times that it should feel as smooth as glass.  Mine feels like it has warts on it!  What am I doing wrong?

[Jeff Farris]

Time and pressure, Herman. Keep on it with both.

[grepper]

I had issues with my stone surface.  The replacement wheel I received has zero problems.  Smoothly grades from 220 -> 1000...  grit.  No sticky spots, no warts or surface aberrations.  Well, there is one perfectly black, 3mm round spot, but it does not seem to effect performance at all.

Of course the wheel is new, with almost no use on it.  But I don't see why the wheel surface, other than needing truing, should change due to time/usage.

My experience with the Tormek is very short compared to many of you obviously way more experienced folks so I may be clueless.  But, that is what I have experienced so far.  One wheel gave me problems, this new one has not.

Mark

[Rob]

Glad to hear your problems are over Mark.

My SB250 Blackstone arrived today. Can't wait to give it a spin (pardon the pun)

I will heed Jeff's advice and not expect the planar blade metal to just "walk off" mind :-)

I think it's first tour might be on a bowl gouge I'm going to grind the wings off a bit further.

[grepper]

Warning:  The following is probably a stupid question!

The Blackstone sounds interesting, and I guess it can work on harder materials where the SB-250 is less effective. 

It's product description is a little confusing insofar as it says, "It does not offer faster steel removal on ordinary carbon steel than the Tormek Original Grindstone."  Then later says, "Its faster material removal is an advantage...".

Then is says it can be graded to a 1000 grit, and "also offers exceptional wear resistance".

Well, that sounds like the perfect wheel for knives etc. because of "exceptional wear resistance" and material removal = the standard SB-250. 

Does that mean it needs truing less often and lasts longer?  Why not just use that all of the time?

Uh, oh! Apologies.  Did not intend to go off topic here.  It was just my next thought.

Mark

[Rob]

No they're good questions which oddly enough I recently asked Jeff to address before I bought mine.  Here's my take from what I currently understand

The blackstone has been made in response to advances in the metallurgy of tool steels. It's particularly designed to help grind high speed steel (HSS) and some other what are called exotic alloys ie like HSS in that they're very hard

Many regular workshop edge tools are made from carbon steel which is relatively soft. The original Tormek grindstone can handle that steel ( might be a chisel or hand plane blade for example).

A newer breed of tools use HSS like electric planar blades and turning tools. They use HSS becuase apart from being very hard it's also more resistant to high temperature than carbon steel. When you're poking a diamond parting tool into a chunk of fast spinning English Oak, believe me you find out just how hot a turning tool can get!

Even more hard and temperature tolerant is tungsten carbide.  This is what they fix to the tips of table and chopsaw blades

The blackstone can handle carbon steel like the original stone. But it can also grind HSS. the original stone really struggles with HSS. Apparently the blackstone can also touch up carbide but not shape it.  Meaning it can re sharpen an already correctly shaped edge but don't expect to shift a lot of carbide.

The stone itself has more abrasive particles per unit measure so it's finer essentially. Also the abrasive is harder so its meant to wear less. (The particles retain their sharp edges for longer)

So I can understand how it outperforms the older type wheel in harder metals. What doesn't make sense to me is why should it not cut carbon steel faster than the original wheel.  However I have no reason to doubt that's the case so like you I can't see any reason why you wouldn't have it mounted all the time. It only offers advantage with no downside that I can see

[grepper]

Rob, "...oddly enough I recently asked Jeff to address before I bought mine."  Obviously you are a man of great intelligence! 

[Ken S]

While becoming familiar with my DBS-22 (drill bit jig), I used both stones.  My unscientific opinion is that the Tormek is essentially designed for the original SG general purpose wheel.  I did not notice a difference between the SG and SB on a 3/8" drill bit.  Both did fine.  I might feel differently with larger bits or more of them.

Since I have both, I would use the SB stone for high speed steel drill bits, planer/ jointer blades and turning tools.  If I only had the SG, I would use it for everything and not worry about it.  While it may not be specifically designed or harder steels, it does a very adequate job. 

Ken

[Rob]

Rob, "...oddly enough I recently asked Jeff to address before I bought mine."  Obviously you are a man of great intelligence! 

Great minds think alike :-)

[Rob]

While becoming familiar with my DBS-22 (drill bit jig), I used both stones.  My unscientific opinion is that the Tormek is essentially designed for the original SG general purpose wheel.  I did not notice a difference between the SG and SB on a 3/8" drill bit.  Both did fine.  I might feel differently with larger bits or more of them.

Since I have both, I would use the SB stone for high speed steel drill bits, planer/ jointer blades and turning tools.  If I only had the SG, I would use it for everything and not worry about it.  While it may not be specifically designed or harder steels, it does a very adequate job. 

Ken

Hi Ken
That's exactly what I did for the first five years of my Tormekking (just invented a new verb, note to self, inform Oxford English Dictionary). And I was happy as the proverbial pig in the poke. Then, mad impetuous fool that I am, I buy the planar jig and well......you know the story

So that's what facilitated the blackstone buy for me personally. I now realise that for bits of steel that are:

a) very long
b) very hard
c) very made of HSS

you could indeed use the SG but life's too short to spend 8 hours grinding planar knives. So I'm with you, if you have the choice, "whack the black" when HSS comes along and "free the SG" otherwise.

I couldnt yet forsee any circumstance where I would use the Japanese soft stone. Because I wouldn't want to be switching stones to hone when I have a perfectly good strop right in front of me

On the other hand......never say never!

[Justin]

And while were on the subject there's something else I wanted to ask about.  I can't ever seem to get my grindstone dressed properly using the fine side of the grader.  You've mentioned several times that it should feel as smooth as glass.  Mine feels like it has warts on it!  What am I doing wrong?

I often use a strip of wet and dry (220 i think) and it does get the stone to have a glass like feel. I have never got the stone to feel quite like that using the grader, it doesn't break down the paper as fast as you might think.

[grepper]

Herman,

When I was having wheel surface problems, Jeff said I probably was not doing enough grading.  Now he as replied to your post with simply, "Time and pressure, Herman. Keep on it with both." 

Hmmm...   I wonder if Jeff might actually know what he's talking about??? 

Could these wheels, in some circumstances, get into a, well, funky state, where they require possibly a resurfacing, and/or a good 15 - 30 minutes of hard pressure with the coarse side of the grader to beat them back into shape, (submission)?

99% of my grinder experience has been with bench grinders, like where you need to grind some stuck bolt head off or some other equally crude procedure.  You know..., walk up, grind away, turn the thing off and walk away.  Since the Tormek, I  realize that I had never really even thought much about the surface of the wheel, unless it was obviously damaged, or ground down to a stub.

I guess that my point is that when it comes to maintaining a fine surface on these water wheels, it's all new an wonderful to me, and I'm just taking pot shots with the 15-30 minutes of restorative grading.

Mark

[Herman Trivilino]

The grindstone does get glazed with pieces of ground steel after it's been used a lot.  This issue had been addressed here in this forum.  As I recall it's important to keep the water in the trough clean.  The magnets help with this, too, as they trap bits of steel and keep them from recirculating and ending up back on the surface of the grindstone again.

I bought a new grindstone a few years ago and the last time I went to use it it way out of round.  So the other day it saw the truing tool for the first time in its life.  I figured that immediately following the truing I'd have my best chance at getting a smooth-as-glass surface.  I wanted to sharpen the kitchen knives and see if I could them as sharp as the new Victorinox 40520 Fibrox 8-Inch Chef's Knife I had recently purchased after seeing it win the best crossover knife test on an episode of County Kitchen.

I failed.  I have never been able to get a knife as sharp as this one was out of the box.  The blade is thin and the grind angle steep.  I think they said on the TV show that these crossover knives have edge angles of about 30 degrees.  The blade is so thin it's impossible to measure the angle with the Tormek jig.

I shall keep trying.