Truing Damaged SJ Stone (the one we thought was beyond hope)

[RickKrung]

Recall that last Fall, at the conclusion of my stints doing farmers markets, my SJ stone got dropped and soaked with acetone.  Massive cracks and chips.  We all thought it was toast.  I gave up on it and even gave up on using an SJ stone altogether.  I was thinking I might try painting the sides with MinWax Wood Hardener (acrylic dissolved in acetone) in an attempt to infuse the acrylic into the stone matrix well below the outer surface, hoping that would "glue" the cracks together enough to make the wheel useful again.  Never got around to trying that. 

I just received today nine knives from the high end steak house in my tiny community.  Nothing special as far as knives go.  But, I wanted to be able to finish them with the SJ stone, so I got out my motorized truing tool and went to work. 

I wasn't expecting much, but I am astounded.  It was VERY out of round and it took a while to get it down to touching around the entire circumference.  The outer surface cleaned up much betting than I expected in the areas where the cracks are.  I can barely see the cracks and barely feel them.  I haven't used it yet on any knives, but it cleaned up so nice, I could be tempted to use it in edge-leading mode from the vertical USB.

See the photos below and then watch these videos.

Cleaned up after fast passes, prior to chamfering the corners

After chamfering, finish slow pass. 

I need to true my SB and SJ stones, so will do them before tackling the restaurant knives.  The six Henckels that I did for the restaurant manager's knives were all done on the diamond wheels followed by controlled angle honing on the leather wheel. 

I am still in disbelief that this SJ stone appears to be in very good shape and very usable.  I will report back after using it with these restaurant knives. 

Rick

[Ken S]

Bravo, Rick! We should rename your stone the SPh-250 (the Phoenix stone, rising out of the ashes).

Keep us posted.

Ken

[RichColvin]

Rick,

Looks great!  What is the final diameter?

Kind regards,
Rich

[RickKrung]

...snip...
Looks great!  What is the final diameter?

Kind regards,
Rich

247.21mm   If this holds (together), plenty of life left. 

Rick

[RickKrung]

After truing the SB and SG stones, I did not use them for the restaurant knives.  I used: Norton 3x for shaping the bevel (12º), the diamonds DC, DF, DE and the SJ wheels followed by controlled-angle honing at 14º using the Tormek compound. 

I don't get it, but it is very difficult to find any of the cracks that were so evident before in the SJ stone.  After truing but before any use there was only one crack visible, from the left edge to bit of a deep cavity near the middle (see first photo below).

There was nothing perceptible different about the stone during use.  No clicks, no chips, nothing.  Just as if nothing ever happened.  It became very dirty from the black marking pen, as usual, but that cleaned up just like all the other times.  (see the other photos). 

I was very pleased with the sharpening results from today's session.  Six of the nine restaurant knives (1 3" paring, 1 - 6", 2 - 8" and 2 - 10").  I think these were the most consistent of any of the knives that I can recall, from the market stuff or any of my recent sharpening.  All below 200 BESS.  Average of the six was 167 BESS (149, 153, 169, 171, 173 and 183).  Three readings were taken on each, base, middle, tip and averaged.  Range of individual readings was from 137 to 200. 

I am glad I procrastinated about buying a new SJ stone, dropping $400 plus shipping unnecessarily.  I'm thrilled with the consistency I'm getting in the edges.  I'm a happy camper.

Rick

[Herman Trivilino]

I don't get it, but it is very difficult to find any of the cracks that were so evident before in the SJ stone.

Hmmm...  Could be the cracks were filled with the slurry created during the truing process. Then, as the stone dried, the slurry in the cracks melded with the rest of the stone. Sort of like the familiar caking process seen in so many granular materials.

The soil here is a mixture of clay and sand. When dry it can be ground up and sifted to create a powder, let it get wet and it will cake together when it dries out and form a clump.

[RickKrung]

I don't get it, but it is very difficult to find any of the cracks that were so evident before in the SJ stone.

Hmmm...  Could be the cracks were filled with the slurry created during the truing process. Then, as the stone dried, the slurry in the cracks melded with the rest of the stone. Sort of like the familiar caking process seen in so many granular materials.

The soil here is a mixture of clay and sand. When dry it can be ground up and sifted to create a powder, let it get wet and it will cake together when it dries out and form a clump.

Possibly.  Hadn't thought of that.  How strong are those clumps?  Likely not very, unless the clay acts as a strong binder, which it can do, take adobe bricks for example.  The cracks were largely no longer visible prior to the truing, albeit, less visible after.  No worries.  I'm not going to rely on the cracks having self healed by such a process and am just glad the stone is servicable again. 

Rick

[Ken S]

Rick,

Your farmers market experience has certainly benefitted all of us. I am pleased that your cautionary tale with your SJ finally had a happy ending. Nice job sharpening those restaurant knives.

I am glad your Norton 3X wheel has served you well. The 3X is the best working coarse wheel I know of for the Tormek.

Keep up the good work!

Ken

[RickKrung]

Following some gracious offline advice from Wootz, I used the leather wheel with compound very sparingly after the SJ stone, and then at the same angle, not 2º greater.  The Tormek compound is coarser than the SJ wheel so doing as I did at the greater angle likely rounded the apexes a bit.  He felt doing only a single pass per side at the same angle would clean up the small burr left by the SJ wheel and result in sharper edges. 

Two of the remaining knives were similar to the others sharpened yesterday - stainless and probably a bit harder than mainstream knives.  One was a 14" filet knife the other a small paring knife.  The third knife was large, 11.5" long, wide and made of carbon steel.  Following Wootz's advice, the two stainless knives turned out sharper than or the same as the sharpest of those from yesterday, filet = 151 BESS, paring = 135 BESS.  The carbon steel knife was the least sharp of all, at 197 BESS. 

I could work with this process a bit more, but I'm now thinking maybe its time to get the paper and felt wheels set up so I can use the finer diamond grits.  After the close of the farmers market seasons, I was burned out on sharpening and put it all away and didn't touch it until about a week ago.  I also got hugely drawn into woodworking and have added a router and table and a table saw to my collection of woodworking tools.  I've also finally used the planer I bought last spring and have noticed a small raised line of wood on some pieces that I planed.  So maybe it is time to put in a new set of blades and look into sharpening the ones that come out.  The Tormek planer blade jig is still in the box, sitting on my shelves. 

Rick

[Ken S]

Rick,

You have been busy! If you have some study time, look up the late Pat Warner. Pat wrote four books and numerous articles. He was head and shoulders the best router man going. If you happen to find a copy of one of his first three books at your library, be sure to notice the credits. I did the darkroom work for Pat and learned a lot from him. Pat was the Wootz of the router!

I am eagerly anticipating season two of the farmers market chronicles!

Keep up the good work!

Ken

[RickKrung]

Rick,

You have been busy! If you have some study time, look up the late Pat Warner. Pat wrote four books and numerous articles. He was head and shoulders the best router man going. If you happen to find a copy of one of his first three books at your library, be sure to notice the credits. I did the darkroom work for Pat and learned a lot from him. Pat was the Wootz of the router!

I am eagerly anticipating season two of the farmers market chronicles!

Keep up the good work!

Ken

Thanks for the tip about Pat Warner.  I'll look for his work. 

I hope that I disappoint you regarding the farmers market chronicles.  I do not want to do that again.  If I do it, it will be on an occasional basis only.  While I learned a lot and it advanced my sharpening skills, etc., I really did not enjoy it.  Particularly the every week thing.  "Having" to be somewhere.  Not for me. 

Sorry,

Rick

[Ken S]

Rick,

No need to apologize. You did the farmers market to help your daughter. You learned and shared a lot from the experience. You also decided it was not something you wished to repeat. I understand that. I spent one weekend demonstrating the Tormek for Affinity Tool, the US importer. It was an interesting experience. I learned a lot and enjoyed it. One unexpected pleasure was meeting Jeff Farris, the founder of this forum and for many years a Tormek rep. Meeting Jeff was like an Old Testament scholar having lunch with Moses. Jeff was demonstrating for Sorby at the time. I asked him how much traveling he did with his job. He told me about thirty four weeks a year. My wife and I are very full time grandparents for our two grandchildren. As much as I like the Tormek, I would not want to give up that precious time to be demonstrating. (I confess that if Tormek ever offers me a week long class in Sweden, I would go....)

I am grateful for the farmers market sharpeners, especially my friend and mentor, Steve Bottorff. I have learned a lot from them and wish them only the best.

Ken