What's the optimum angle to sharpen a skew? I'm looking for the best balance between sharpest edge and holding the edge for a reasonable time.
[OP]
Member
What's the optimum angle to sharpen a skew? I'm looking for the best balance between sharpest edge and holding the edge for a reasonable time.
Member
Sorry, but you'll find the definition of optimum to be relative to how many people respond to your question. At some point, someone will simply tell you to experiment and you'll find an angle you're comfortable/happy with. THAT said...see the web link below, it has some good starting points. Good luck...
http://www.woodturningvideosplus.com/bevel-angles.html
Member
I use about 40* and I think that is fairly common.
If you go to about the 2:30 minute point in this video, Allan Batty describes why folks use different angles. (25*-55*)
https://www.youtube.com/watch?v=KfeLAHQSbqk#t=15
"I became insane, with long intervals of horrible sanity." - Edgar Allan Poe
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Optimum depends in large part on what kind of wood you are cutting. Alan Lacer teaches that the bevel length should be 1.5 times the thickness of the steel. Not sure what angle that works out to.
Retired - when every day is Saturday (unless it's Sunday).
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Originally Posted by Thom Sturgill
For other folks who are very very persnickety..( There must be one out there, there always is.)
The Triangle Calculator says........ 38.942*
"I became insane, with long intervals of horrible sanity." - Edgar Allan Poe
Member
Dang! Michael, my protractor just won't read that angle. Guess that I'll just have to stick with sharp enough.
Bill
On the other hand, I still have five fingers.
Member
I agree with John's definition of optimum. I have two sets of skews which are sharpened with two included angle & bevel angle preferences - one set approx 45 to 50 degree included angle with a 20 degree bevel angle; the second with 25 to 30 degree included angle with a 30 to 35 degree bevel angle.
The first preference will hold an edge longer with particular cuts on Aussie hardwoods but sacrifices cut quality & is a "more forgiving grind" ; the second performs better on softwoods, particularly planing cuts, and leaves a cleaner cut, but is more "grabby." They work for me on our timbers.
Contributor
I shoot for an included angle of about 40° (20° each side) and a skew angle of 30° slightly crowned in the middle. I find this to be perfect for getting the cow manure out of my lug soled work boots although I'll admit that the angle is a bit thin for prying open dried shut paint cans.
Bill
Member
I've just recently become a skew convert. Like what I am doing, but my skill with the skew is still novice, at best. I took a class with Alan Lacer, and he advocates the bevel angle to be 1.5 times the thickness of the steel.....I guess you could calculate the bevel angle from there. All I know is, I tried my method, then his.....had much better and easier cuts with his method.
Contributor
My favorite is one of those slightly rounded 1" skews (thicker in the middle) and I wonder if I should still sharpen it flat, or roll the bevel from side to side?
Right now, I am using it rounded (the way it came) and it works well.
Member
I am assuming you are referring to an "oval skew"
by "rolling the bevel" - do you mean putting a very slightly rounded edge on the leading cutting edge? If so - you could try it, but I don't think I've seen that done.
I hope you don't mean to roll the TOOL on it's rounded edge while trying to sharpen it - that will end up making it into some sort of strange "thing" that might not even cut.
with an oval skew the key to sharpening is to make sure you hold it flat against the tool rest the same way, every time. I would build some sort of jig to hold it as flat as possible while sharpening.
Contributor
Not really rolling it, just following the oval shape to create a slightly curved leading edge. That's the way I got it and I continued to sharpen it that way ever since (my other skew were the conventional flat ones, sharpened the usual way) and it works fine. Just hadn't seen it before and thought I'd through out the observation.
Perhaps I'd better snap a photo and post it.
Russell Neyman.
Writer - Woodworker - Historian
Instructor: The Woodturning Experience
Puget Sound, Washington State
"Outside of a dog, there's nothing better than a good book; inside of a dog it's too dark to read."
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Russell, I guess you are talking about the way Alan Lacer grinds a skew with a curved cutting edge but on an oval skew - http://www.popularwoodworking.com/pr...he-skew-chisel
Contributor
That's it, Geoff. Except with an oval skew.
Moderator
Like others said, there is no one optimum angle. I use a number of different angles. For example, a sharper (narrow) angle usually cuts cleaner and can get into tighter places but a larger angle is more forgiving. Some woods, such as osage orange, will break out splinters on long, thin spindles on planing cuts with an angle that's too small.
I never paid any attention to the actual angles I grind on my skews so your question got me curious. I got out the gauge and measured 12 of my skews tonight. (I used a Tormek gauge that can measure every 5 degrees.) A couple were between 30 and 35 degrees, most were close to 40 degrees, some were about 45, and a few were over 45. Two were 60 degrees! I had no idea.
I have one wide skew with a curved edge sharpened at 60 degrees. This is way too "blunt" to cut fine detail cleanly on small diameters but it is the most forgiving skew in the shop - it's hard to make it catch even if you want to! This is the skew I usually start beginners on. I always start beginners on spindles and with a skew after the 2x2 wood is rounded with a roughing gouge. (Experts say spindle turning will teach tool control better and quicker than face turning and I can believe it.)
The small angle skews are better for very narrow v-grooves, end grain, and getting into tight places.
I see that my favorite skews for medium and small spindles are sharpened around 40-45 degrees. My favorite skew width for this is 1/2". For larger diameters wider skews are better.
As for staying sharp the longest, I don't see a big difference in the wider or narrower angles, at least between 30 and 50 degrees. I think the type of steel and the quality of the edge makes more difference. I have a handful of Thompson Tool skews which seem to hold the edge the best. And if I take the time with the Tormek to put a polished edge on a skew (or gouge) the edge on any tool lasts much longer. (Compare the edges with a microscope and you can see why.)
Note that some of my skews are for special purposes and don't get used often. But for the skews I use the most are duplicates - I sharpen two or more very much the same. When one gets dull I just put it in the sharpening tray and grab another one. This way I can keep turning and don't have to stop to sharpen. When enough get dull I have a sharpening session. I turn wood for fun and I don't think it's fun to stop in the middle of a piece and go sharpen. (I do the same thing with my spindle and bowl gouges too - I keep four of my favorite Thompson spindle gouges sharp and ready to swap in the same handle.)
There is also another reason I've found to have an identical skew at hand. The dullness of any tool sneaks up on us so slowly that sometimes we don't realize it is getting dull until it is really dull! If I even THINK a skew might be getting dull I just try making a cut with a sharp one. If it doesn't cut any better then it's either just a chunk of problem wood OR my technique stinks and it's time for me to quit and go to bed!
JKJ
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