Turning breakthrough

[Alan Weinberg]

You old guys will laugh at this since you already know what I’m about to write—when I started turning 2 years ago, I was told of the importance of sharp tools. Sharpening was hard to learn and I started out with cheap aluminum oxide wheels of 80 and 180 grit. And I sharpened my tools. I thought they were sharp. They weren’t.

Recently I upgraded and bought a CBN wheel from D-way, 220 grit. And I thought my tools were sharp when I switched to that. They weren’t.

I was still getting tear out and doing a lot of sanding, usually starting at 80 grit.

So in December Rockler had a sale on a 600 grit CBN wheel. I bought it. Delivery kept being delayed and it finally arrived a couple days ago. Took almost 3 months.

I used it today. And then turned 3 pieces—walnut, eucalyptus, olive—and no tear out! Started sanding at 180.

Blew my mind. I thought I had a technique issue hearing that others had little tear out and I had a lot. I had turned up my rpm, tried shear scraping, but still had tear out and I thought my tools were sharp. They weren’t. But they are now. Lesson learned. Finally.

 

[Gabriel Hoff]

You old guys will laugh at this since you already know what I’m about to write—when I started turning 2 years ago, I was told of the importance of sharp tools. Sharpening was hard to learn and I started out with cheap aluminum oxide wheels of 80 and 180 grit. And I sharpened my tools. I thought they were sharp. They weren’t.

Recently I upgraded and bought a CBN wheel from D-way, 220 grit. And I thought my tools were sharp when I switched to that. They weren’t.

I was still getting tear out and doing a lot of sanding, usually starting at 80 grit.

So in December Rockler had a sale on a 600 grit CBN wheel. I bought it. Delivery kept being delayed and it finally arrived a couple days ago. Took almost 3 months.

I used it today. And then turned 3 pieces—walnut, eucalyptus, olive—and no tear out! Started sanding at 180.

Blew my mind. I thought I had a technique issue hearing that others had little tear out and I had a lot. I had turned up my rpm, tried shear scraping, but still had tear out and I thought my tools were sharp. They weren’t. But they are now. Lesson learned. Finally.

Yup!! I have learned a lot of turning problems are due to poor equipment!

 

[Bill Alston]

It took me a while to appreciate this as well Alan. An acute angle doesn’t mean a sharp tool. A while ago I started finishing off the sharpening process with an 800g belt and noticed the difference straight away on spindle work.

 

[John K Jordan]

You old guys will laugh at this since you already know what I’m about to write…
…CBN wheel from D-way, 220 grit I was still getting tear out and doing a lot of sanding, usually starting at 80 grit.
… 600 grit CBN wheel. I bought it. Delivery kept being delayed and it finally arrived a couple days ago. —and no tear out! Started sanding at 180.

No laughing here, not even a chuckle! (Caveat - I am an old guy and have some experience but I’m in no way an “expert.”)

I teach what I call “sharp, sharp, sharp, shaving sharp” and demonstrate by shaving hair off my arm.
I think tear out can be a combination of things like:

• tool used
• turning technique
• the type of wood
• figure and grain orientation
• localized problem spots in the wood
• and tool control

IMO sharp, sharp, sharp tools can make a huge difference.
(There are things, such as surface treatment, that can be done to minimize tear out, but sharp sharp turmps sharp)

After experimenting for years with various sharpening methods (conventional grinding wheels, Tormek water wheel, various CBN grits, different grinds), I am quite happy with my current setup:

• 60 grit CBN on bench grinder for shaping/reshaping tools (I use the “1/2 speed” bench grinders).
• 600 grit CBN on bench grinder for sharpening almost everything.
• 1200 grit CBN on a Tormek (no water) for sharpening my spindle gouges.

I use the 600 grit for skews, parting tools, bedan, bowl gouges, scrapers, negative rake scrapers, hand scrapers, etc.
I remove any burrs by stropping on the Tormek flat and contoured leather wheels.
All scrapers have a burnished burr applied by hand.
When needed, I restore the “shaving sharp” edges on skews with my custom honing board.
Note: I did try a 600 grit CBN on the Tormek but like the 1200 grit better for my spindle gouges, put the 600 on the shelf. (I keep multiple identical spindle gouges and when one starts to get dull I set it aside and get out another one and keep turning. When all are dull, I sharpen them all.)

Besides the sharpness, I think tool control is the biggest issue. Unfortunately, starting and sticking primarily with bowl turning is not always the quickest way to go. Some experts suggest starting with spindle turning to learn fine tool control. I strongly agree.
They say perfecting spindle turning first teaches that tool control that will let you turn anything - unfortunately, they say it doesn’t work the other way.
(I have references and my own observations of students.)

Unfortunately, spindle turning is not glamorous the to the turner addicted to bowls, bowls, and bigger bowls. (I have other addictions.)
But when I observe some of the best woodturners I know, ALL of them are extremely good with spindles - even though they can turn anything.

BTW, when I started turning I learned mostly from books, then took a class on bowl turning. There, I was taught what turned out to be several very bad techniques about turning and sanding, I’ve since learned better ways. I now turn bowls and platters with rarely a spot of tearout,, smooth with NRS and hand scrapers, and usually start sanding (by hand) with 320 grit, sometimes start at 400. I have one piece I show to students/at demos that was sanded only with 600 grit. (Don’t get me wrong, this is not for bragging rights - I’ll certainly go to coarser grits if needed.) Also, I now NEVER power sand with rotating disks. With other methods there is no need, and far less dust goes into the air. Most of my sanding is by hand with a small piece of sandpaper backed up with a soft eraser. And I’d be lost without my custom hand scrapers.

One big note: I almost always turn dry wood, small or large. (The biggest problem is GETTING dry wood without spending a fortune but that can be solved) Don’t misunderstand, I HAVE turned a lot of green over the years and it’s far easier to turn (almost too easy) but I don’t like the wet mess, the smoothing process and the natural warping. I know many do and that’s OK with me. There are enough green wood bowl turners, I’d rather do something else.

(There is a little trick John Lucas taught me to repair the occasional small speck of tear out, described earlier here at least once.)

Oh, and to really experience the difference, try chip carving (or any carving by hand) without razor sharp tools. Or better, don’t.

JKJ

 

[robo hippy]

When turning end grain, it is possible to get surfaces that are totally free of tear out, as long as you are cutting in the proper directions. With bowls/side grain, the bowl has side grain so you are cutting with and then against the grain. There is always tear out because when you cut against the grain/up hill, there are unsupported fibers. Depending on the wood, this can be minimal or a lot. A 600 grit wheel will make a big difference in punky woods, and also in softer woods that are prone to tear out. Even if you can't see it, you can feel it with your fingers. You can also see it with lighting that goes across the grain, and it will appear to be lighter in color than the rest of the wood around the bowl.

robo hippy

 

[John K Jordan]

When turning end grain, it is possible to get surfaces that are totally free of tear out, as long as you are cutting in the proper directions. With bowls/side grain, the bowl has side grain so you are cutting with and then against the grain. There is always tear out because when you cut against the grain/up hill, there are unsupported fibers. Depending on the wood, this can be minimal or a lot.

You’ve got the part about the type of wood right. But I seldom get tearout on the sides/insides of bowls in face grain with wood like dry cherry, walnut, maple, persimmon, mahogany, cedar, olive, etc, at least none I can see or feel after 400/600 sanding and finish. (Sharpening to 600 grit and stropping to razor sharp, or using a sharp Hunter Hercules.) I find punky wood more challenging. Don’t know about wet wood, not much experience with that.

BTW, on some pieces where I’m “cutting air” I cut uphill against the grain on purpose, for a necessary reason (explained in my Small Squarish platters demo). But sharp sharp sharp is needed with a delicate touch (a “whisper” cut). Heavy hand not allowed, or yes, it will rip the fibers out of the wood.

JKJ

 

[Sam Fleisher]

Just to play devils advocate- I only sharpen to 180 with a cbn wheel because that was the consensus I got from the hive mind here when I started.

But hive or herd intellect, call it what you will. Now I feel the need to go buy a higher grit wheel just because. Thanks... I'm still one tool away from greatness I guess.

 

[Kent Reisdorph]

Just to play devils advocate- I only sharpen to 180 with a cbn wheel because that was the consensus I got from the hive mind here when I started.

But hive or herd intellect, call it what you will. Now I feel the need to go buy a higher grit wheel just because. Thanks... I'm still one tool away from greatness I guess.

My Verigrind is set up on my 360 grit wheel. I don't like removing it for non-bowl gouge sharpening, so I just use the 80 grit wheel on my scrapers, spindle roughing gouge, etc. Works fine for me.

Someone did an extensive test here a year or so back. The summary (if I remember correctly) was that the edge on the 80 grit wheel was not noticeably different than the higher grit wheel.

 

[Alan Weinberg]

the edge on the 80 grit wheel was not noticeably different than the higher grit wheel.

Hard to believe.

 

[Kent Reisdorph]

Hard to believe.

It might have been this thread, but the one I remember had closeups: https://www.aawforum.org/community/threads/sharpening-grit-test.22178/

 

[robo hippy]

I have mostly 180 and 600 grit CBN wheels in my shop. There is a very noticeable difference between the edges from the 180 and the 600 grit. Mostly about getting a cleaner cut, especially on punky wood.

robo hippy

 

[John K Jordan]

I have mostly 180 and 600 grit CBN wheels in my shop. There is a very noticeable difference between the edges from the 180 and the 600 grit. Mostly about getting a cleaner cut, especially on punky wood.

robo hippy

For me there is a difference depending on- depending on the wood and what I’m cutting. For example, I found that if I’m careful I can sometimes turn a spindle that needs no sanding. I have an example I show of one from holly that has zero sanding. With a coarser grind on very fine-grained wood there are sometime tiny scratch marks on ebony that need to be hit with at least 600 grit paper. Or coarser, if I’m not having a good day (or good luck!)

I sharpen scrapers, skews, and most gouges on 600 grit cbn on a bench grinder, spindle gouges with 1200 grit cbn on a Tormek. I always touch up tools with the leather wheels on the Tormek with a little of their stropping/honing compound and touch up some tools with the little Extra Fine EzeLap diamond hones. I think the edges last a little longer but have’t done any careful comparison tests.

JKJ

 

[William Rogers]

I won’t get a 600 grit. 90% time you are just getting wood out of the way and a 180 grit IMO is more effective. For final cuts I hone and feel I get equal to or better than 600 grit. I’m sure a 600 grit is great for the final cuts, but just not worth it to me. For skews, scrapers, parting tools and etc I use the Sorby ProEdge belt sander. Normally 220, but have belts up to 1200. I prefer non hollow ground, but that could be personal preference as much as anything.

 

[Odie]

For final cuts I hone and feel I get equal to or better than 600 grit.

Hi Bill....

The reason honing by hand with 600gt creates a better, sharper edge.......is because that edge can be created from multiple directions.

Any edge created by a fast spinning wheel is limited to the fineness of the edge that can be created from a single direction.

And THAT..........is the difference!

=o=

 

[Bill Boehme]

As Alan Lacer tells his students, "if you can see the edge then you don’t have an edge."

 

[hughie]

I think we have all been there at some stage. Due to my engineering background I started out with 80/120 on a dual wheel grinder many years ago slowly graduated to diamond hones and CBN 140/600 and finally 1000 for my carbide gouge tips. A bit slow out of the gate due the high cost of CBN in the beginning, but the difference between a 80 grit edge versus 1000grit is bordering on night and day for me, theres no going back.

 

[John K Jordan]

As Alan Lacer tells his students, "if you can see the edge then you don’t have an edge."

That's old knife sharpener wisdom too - see any light from an edge, dull knife.
Look at a tool fresh off a CBN wheel or grinder with a microscope. An eye-opener.
I use a low power stereo microscope for wood ID, examining bugs, feathers, pond water, splinters, turning tools, knives and scalpels. (BTW, a #11 scalpel, a stereo micro scope, and a deeply embedded splinter in my finger - quick fix. Although a simple splinter extraction almost makes my Lovely Bride pass out.)

JKJ

 

[Bill Alston]

Digging splinters out with a scalpel blade happens more often than I’d like when doing metalwork. Some are too small to see with the naked eye so I use a linen tester (type of open magnifier) to help see what I’m doing.

 

[John K Jordan]

Digging splinters out with a scalpel blade happens more often than I’d like when doing metalwork. Some are too small to see with the naked eye so I use a linen tester (type of open magnifier) to help see what I’m doing.

I have a variety of lighted and passive magnifiers, but some things I really like about the stereo microscope: it’s true stereo so what you see is 3-dimensional which makes self surgery easier, has a good light built in, excellent focus control. (For those who haven’t done this, I use a #11 pointed blade in a scalpel handle, slit the skin starting the splinter entry point, then cut upwards as I go deeper until I locate the end of the splinter. Cut along the splinter to expose the length. Pry it up and out with the point of the scalpel, look for and remove any remaining bits (especialy deeper points), add a bit of disinfectant, and a bandaid if I’ve feeling wimpy.

The microscope leaves with the operating subject and the operating fingers free, but I suspect a good magnifier on a stand would work ok.

One thing a metal worker taught me was to keep a strong magnet hand in the event of a steel sliver in the eye. I wear good eye protection an have never had to use it. I did get a small, thin wood fragment in my eye once and had to visit a professional to remove it. No lacerations or embedded splinter, just a tiny flake from handling lots of wood in a warehouse, but the piece got stuck under the eyeball where no amount of irrigation on my part would remove it.

I was 30 minutes away when I called my eye dr. They were closing but one eye doctor waited until I came. He found and removed it in about 10 seconds. Bless him! Saved a trip to the er.

JKJ

 

[robo hippy]

Hi Bill....

The reason honing by hand with 600gt creates a better, sharper edge.......is because that edge can be created from multiple directions.

Any edge created by a fast spinning wheel is limited to the fineness of the edge that can be created from a single direction.

And THAT..........is the difference!

=o=

Odie, color me puzzled.... I am not sure how coming at the edge from different directions makes a difference. For sure, there is a huge difference between "grinding" and "sharpening" which is how much pressure you are putting on the tool into the grinding wheel as you sharpen.

robo hippy

 

[Odie]

Odie, color me puzzled.... I am not sure how coming at the edge from different directions makes a difference. For sure, there is a huge difference between "grinding" and "sharpening" which is how much pressure you are putting on the tool into the grinding wheel as you sharpen.

robo hippy

Howdy robo.....

As someone who was a fanatical hunter at one time, I learned how to sharpen a knife to a keen edge. It was way back then when I realized that keen edge can be improved by using alternating directional honing techniques. .......and, Yes.......you are absolutely correct, robo.......the pressure one uses to create a keen edge is likewise important to the results possible.

=o=