Opinions on Rocks/Stones for a Cats Claw Sharpener

[5quarter]

Ideally, you want that edge to "stand up". When a sharp knife gets dull, its because the edge has laid over to one side or the other. honing should not remove material, just bring the edge back in line with the blade body. since you can't really "hone" the tips of the teeth,  you have to grind your profile in such a way that the tip is ground straight across it's full width as Peter says, and that the leading edge of the tip has not rolled back. it is as much art as science to get your sharpener and technique dialed in to the point where you get razor sharp tips every time, but I think you're almost there. Peters right on the money when he says to grind the back to get the tip back to full thickness. the face grind should be just barely enough to remove the burr from grinding the back and establish that "invisible" edge. in your photo,  I can't tell whether the edge is standing up or not. if that burr doesn't come off easily with your fingernail, it's not a burr, but overheated edge material left over from grinding the face too heavy. sending it around once more very lightly should clean it up. your determination to get the sharpest possible blade will really pay off, not just in quality and production rate, but in the increased confidence in your ability to consistently cut great lumber.

[Peter Drouin]

Ideally, you want that edge to "stand up". When a sharp knife gets dull, its because the edge has laid over to one side or the other. honing should not remove material, just bring the edge back in line with the blade body. since you can't really "hone" the tips of the teeth,  you have to grind your profile in such a way that the tip is ground straight across it's full width as Peter says, and that the leading edge of the tip has not rolled back. it is as much art as science to get your sharpener and technique dialed in to the point where you get razor sharp tips every time, but I think you're almost there. Peters right on the money when he says to grind the back to get the tip back to full thickness. the face grind should be just barely enough to remove the burr from grinding the back and establish that "invisible" edge. in your photo,  I can't tell whether the edge is standing up or not. if that burr doesn't come off easily with your fingernail, it's not a burr, but overheated edge material left over from grinding the face too heavy. sending it around once more very lightly should clean it up. your determination to get the sharpest possible blade will really pay off, not just in quality and production rate, but in the increased confidence in your ability to consistently cut great lumber.

Thanks 5quarter for agreeing with me on this . I won't go into how important it is for Coolant.

[jclvsall]

Yeah Deepwoods that is the one.  You can take the specula off and use it like a mini lighted magnifying glass. 

Brian

[Chuck White]

Thanks 5quarter for agreeing with me on this . I won't go into how important it is for Coolant.

If you're using a sharpener with coolant, whether water or oil, you can make a heavier grind than with the Cat Claw without damaging your blade!

Which is why I mentioned take a light grind or you'll burn the blade if you're using the Cat Claw!

[CooksSaw]

I'm kind of getting the hang of my Cats Claw sharpener, and I've been using the blue rocks from Cooks.  I've been sharpening a lot, catching up on a stockpile of dulls, and am significantly wearing down my rock.  I've got a couple spares, but it got me thinking at what options were available, and started searching old posts for info. 
Is there a better choice than what I'm using?  Something that cuts faster or lasts longer?  What about the Ruby from suffolk?  I've read that some folks prefer that.  Or should I try a black rock from Cooks or WM?  What about a CBN on a dry grinder, how long does it last? 
I have found a lot of choices out there, all claim to have advantages, I just want to avoid having to buy one of all of them to try out.
Thanks,
YH

YH,

I'll send you a ruby rock so you can try one out.

The type of grind rock that is best for you comes down to a matter of personal preference. This is especially true with the blue and ruby rocks as they are very similar. However, keep in mind that both of these rocks only require a light 'dressing up' as they wear. The tendency is to treat them as a harder rock which is counter to what a ceramic rock requires.

Remember that the objective is only to remove the dull grit; not to entirely re-shape the rock. This can usually be accomplished with a light tapping of the rock with a shaping stone rather than continuous contact which can result in excess grit removal.
Ultimately, any of the dry grind rocks can produce a sharp edge; how hard you grind, and how aggressive you are with shaping them are two major factors that will determine rock life.

James

[5quarter]

Peter and Chuck...That's the nice thing about the CBN sharpener. It really takes the worry out of burning the tips of the teeth. I wonder why Cooks hasn't engineered a coolant option for the cats claw? you'd have the versatility of a drag type sharpener with the cooling ability of a full grind type sharpener.

[YellowHammer]

YH,
I'll send you a ruby rock so you can try one out.
James

That is service!  Thanks! I didn't even know you guys offered a ruby rock.  I'm looking forward to trying it out.

I've been taking advantage of the advice and latest cold spell to "hone" my sharpening technique : and was able to buy one if the little optiscopes at a local drugstore yesterday.  I also added some extra light and have a much better view of the corners of the teeth and can now better see the little glint indicating when its still just a little dull. 
I appreciate all the advice on the subject, and have to explain that one of the reasons I'm trying to get my sharpening technique dialed in is that as a business, when I turn the mill on, I need to be cranking out the wood full steam and even with the limited sharpening and setting I've been doing I'm seeing a substantial increase in sawing speed and quality. 
YH

[Peter Drouin]

Yes YH, get your sharpening down that is as important as selling the lumber.
Best of luck with your blades and selling wood.  8) 8) 8) 8) 8) 8) 8)

[bandmiller2]

To me the difference between the blue and ruby ceramic wheels is the color. If sharpening is done right on the cats theirs no need for coolant. Coolant is used when you want to hog off a lot of material to speed up a sharpening process. Frank C.

[CooksSaw]

That is service!  Thanks! I didn't even know you guys offered a ruby rock.  I'm looking forward to trying it out.

I've been taking advantage of the advice and latest cold spell to "hone" my sharpening technique : and was able to buy one if the little optiscopes at a local drugstore yesterday.  I also added some extra light and have a much better view of the corners of the teeth and can now better see the little glint indicating when its still just a little dull. 
I appreciate all the advice on the subject, and have to explain that one of the reasons I'm trying to get my sharpening technique dialed in is that as a business, when I turn the mill on, I need to be cranking out the wood full steam and even with the limited sharpening and setting I've been doing I'm seeing a substantial increase in sawing speed and quality. 
YH

You should receive your rock by Friday.

One other small bit of advice as you're learning to sharpen (especially for others); sharpen until all the dull points (rounded sides) become keen (squared), then very lightly sharpen one more time.  That last light grind puts a polished finish on the edge and will help that blade rip through some wood and have customers coming back for repeat business.

James

[bandmiller2]

James, is there a best speed to set the feed to get the sharpest edge with the cats claw.?? Frank C.

[LeeB]

I don't know if it's best or not, but I like to set my dial between 3 and 5 with a real light kiss on the blade.

[CooksSaw]

James, is there a best speed to set the feed to get the sharpest edge with the cats claw.?? Frank C.

Frank,

The best grind is almost always going to come from a slower grind as it hones the edge; the faster the grind the rougher the finish. Both are 'sharp' however the slower grind will produce a keener edge.

Having said that, we have found that sharpening a tooth every two seconds or 30 teeth per minute is a speed that will hone whereas moving up to 50,60 or higher produces a rougher finish.  Both will produce sharp blades. Determining whether the performance difference between the two is worth the extra time it takes to sharpen will be up to you.

Hope that helps.

James

[YellowHammer]

Very useful information.  I received my ruby rock, and I'm going to experiment a little with both rocks, and feed speeds during the rain tomorrow and try to take some decent pictures of the results.
If I can't be sawing, I can be sharpening.
YH   

[Chuck White]

James, is there a best speed to set the feed to get the sharpest edge with the cats claw.?? Frank C.

Frank,

The best grind is almost always going to come from a slower grind as it hones the edge; the faster the grind the rougher the finish. Both are 'sharp' however the slower grind will produce a keener edge.

Having said that, we have found that sharpening a tooth every two seconds or 30 teeth per minute is a speed that will hone whereas moving up to 50,60 or higher produces a rougher finish.  Both will produce sharp blades. Determining whether the performance difference between the two is worth the extra time it takes to sharpen will be up to you.

Hope that helps.

James

Just to add a note to James' post.

Good info indeed, but we all must remember that grinding  s l o w  we need to be less aggressive with our grind or we'll end up burning the band!

[YellowHammer]

I've been using the advice from everybody to do a little sharpening between rainstorms and sawing jobs.  Here are a few pictures I thought would be interesting.  I took these viewing through my optiscope.
The first picture is of a tooth showing the glint of an unsharpened end corner of the tooth. 


The second picture is of a tapered tooth, with a slightly tapered or rounded edge of tooth.


They finally, I got to this, a nice shaped chisel edge

YH

[5quarter]

much better results! are those first 2 pics of teeth that have already been around the sharpener? are you using the new wheel James sent? how's it working out?

[customsawyer]

When you start looking at the fine details your results will greatly improve.

[Peter Drouin]

Your on it now YH  8)

[bandmiller2]

Ayup, with any tooth or bit its the corners that are most important and dull first. Frank C.

[Peter Drouin]

Ayup, with any tooth or bit its the corners that are most important and dull first. Frank C.

[barbender]

I need to get me one of them thar magnifiers ;)

[YellowHammer]

are those first 2 pics of teeth that have already been around the sharpener? are you using the new wheel James sent? how's it working out?

Yes the first 2 pics are of teeth that had already gone around. 
The first picture was after the first pass, and if you look, it also shows a slightly burned tip. 
The second photo was after the second pass, and the third photo was after the third pass. 

I have been using the Ruby rock, and it does seem to have subtle differences, but I want to get a little more seat time with it before I say anything...but it certainly sharpens blades well, at least as well as the blue rocks.

The magnifiers work great, I think I paid 8 bucks at the local drugstore for,it.


YH

[36 coupe]

I'm thinking of getting one of the magnifying lenses on an arm to make it easier to see the details.  Here is a closup picture of a tooth that seems to be about as sharp as I can get it.  So I used the Cooks blue rock for this, and noticed that the grit of the rock leaves little grind marks in the tooth.  I assume these are normal and OK.  Also, I notice a little burr on the very tip of the tooth left over from the grind rock.  On a knife, this burr would be removed with a finer grit stone or by honing, but I'm thinking that a final, light polishing pass might remove it.  On the other hand, I don't even know if matters in a real sawing situation.
YH I would switch to a finer grit wheel if I saw marks like that on  saw teeth.Try Norton wheels 32a and 36a.These numbers refer to wheel type.
 

[36 coupe]

After looking at the photos I wonder if the face of the tooth is exactly 90 degrees from the body of the saw.Hard to see on a thin blade.When I sharpen large rip circular blades I find a 5 degree bevel on the tooth face makes a saw cut faster and stay sharp longer..The scratches I see say that the wheels have too coarse a grit.Band saw teeth are induction hardened.Hard steel calls for soft grinding wheels and light grinding.I think you should do a light grind AFTER setting.Also only the tip of the tooth should be set.Setting the whole tooth make a saw run hard.Takes more pressure to hand feed a table saw.