Turning Tool Steels

Discussion in 'Newbie' started by Ed Nygard, Oct 4, 2017.

  1. Zach LaPerriere

    Zach LaPerriere

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    Thanks for the report, John!

    My experience is that the M42 gives the sharpest edge, at least on the 800 grit CBN wheel. V10 just doesn't take as fine of an edge. I can usually feel the difference running my finger across it, and I can certainly tell in finish cuts. I'd say it's the difference of a whole grit for finish cuts for me and the softer torn-grain-prone woods I turn.

    I still keep my V10 tools in the mix, I just don't use them for finish cuts.
     
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  2. RichColvin

    RichColvin

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    This sounds like a golf discussion :

    "Did you ever take a lesson ?"
    "No, but if I only had that new club, I'd hit 3 strokes less ...". ​

    Rich
     
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  3. robo hippy

    robo hippy

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    I can not tell any cutting difference between the V10 and M42. Most of the time I am sharpening on 180 grit CBN. My finish cut is always a shear scrape, but I am using the NRS more across the bottom of a bowl. I mentioned to John earlier that I had honed one of my Big Ugly tools, and was very surprised at how clean and sharp it was, and it is considerably more coarse than any of the turning steels that we use (particle metal similar to carbide, but coarse, not line the micro grain carbides we have now, but sharpens fine on standard wheels as well). I just heard that Dave Schweitzer (D Way) has a new U flute gouge, and may have to try that. I don't care for his V flute that much, and generally use the Thompson V or U. I do prefer more open flutes.... The Big Ugly is my roughing tool, the V10 or M42 are my shear scrapers, though some times the tantung works fine. Funny, green myrtle doesn't shear scrape with tantung well, but it does excellently when dry....

    robo hippy
     
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  4. john lucas

    john lucas

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    Zach you may just have to sharpen the V10 longer. I found that on my V11 Thompson tools I had take several more strokes on the sandpaper to raise a burr than I did for the HSS tools. I also found that It tool longer to properly strop the V11 than HSS. Apparently the metal is tougher at least as far as abrasives are concerned. The difference in edqe quality was only detectable at extremely high magnification or with a sensitive tester like the BESS. Early on when the Particle metal tools came out people were complaining about them not getting sharp but then we learned that they were doing it the same was as their old HSS tools and you simply had to grind a little longer to get all the way to the tip. Are you seeing a little gray burr at the tip when you grind. I find on CBN wheels you can tell when you grind all the way to the tip by the very small gray line that appears on the tip. I think maybe it's piled up metal dust but I don't know for sure. I do know that when I see that I have ground all the way to the tip and it's time to flip the tool over (if it's a skew or parting tool). I also hone the inside of my flutes with a fish hook sharpener. Many of my tools don't have a polished inner flute so they don't get as sharp as they could. By honing the inside just a tiny bit I am polishing that portion of the flute and my edges are sharper.
     
  5. john lucas

    john lucas

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    Wow I had not heard of those charts. I looked. Very confusing. Would love to know the process they used to come up with those numbers. There must have been 30 different charts of things. Thanks for bringing up those charts.
     
  6. Zach LaPerriere

    Zach LaPerriere

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    That's interesting, Robo. I don't sheer scrape unless I absolutely have to. You'd scoff at the woods I turn! But that's what I have here in Alaska... My finish cuts on the outside are steep sheer cuts, and interior finish cuts are light and slow.
    For what it's worth, I love Dave's big U shaped 3/4 gouge. But I'm a gouge guy. I should try a Big Ugly tool for roughing. My experience so far with scraping has been that the tear-prone grains cut much better than scrape. I think (though I'm not certain) that this is also true for roughing softer tear-prone woods.

    John, thanks for the thought on not sharpening V10 long enough. I know it takes longer to sharpen—I started with V10 before switching to M42. Since the edges last about the same, and because I sharpen to 800, there's a clear time saving for me with M42. At 800 grit I don't see the gray line you're talking about, but I have seen it on courser grit wheels.

    You are right about the flute. This may be part of the reason for my bias against the V10...it's so hard that the milling marks are impractical to remove. I have removed them, beginning with course sandpaper and with CBN and ceramic slipstones. And the edge is definitely better.

    It is very possible that 800 grit is just a bit too fine for CBN sharpening to get a keen edge on V10. I should have a disclaimer that my results and use are very different than everyone else. For most people and most woods commonly turned, a courser sharpened edge is sufficient, and has little to no advantage over a finer sharpened edge.

    Another thing I've noticed is that a well honed sharper edge on both M42 and V10 is not superior to a 800 CBN edge in practical use. I can only surmise that Robo (I think it was you?) is right about the sawtooth edge standing up longer.
     
  7. robo hippy

    robo hippy

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    Scrapers for a finish cut work great in end grain, but on bowl grain orientation, usually not. I have been playing with a 70 degree HSS scraper with the burr totally honed off. I can get an excellent surface on hard maple. The key here is most likely the specific wood. Harder woods will take scrapers better than softer woods. Yes, the scraper is an excellent tool for removing a lot of bulk in a hurry. I started into the shear scraping after seeing Jimmy Clewes who uses the shear scrape as his final cut. According to him, the bevel rub leaves a burnished surface, which I think is valid, though how burnished depends a lot on how heavy or light your bevel rub is. His comment about sanding a burnished surface was some thing like when he starts to sand, the first thing you have to do is cut through the burnishing before the abrasives really start to cut. That seems to make some sense, but as near as I can tell, it is highly variable. I generally don't turn alder, which is too soft for my taste, and it does not cut well. That may be a wood where the 800 grit edge is preferable. I have found with my shear scraping, and NRS (negative rake scrapers), they both work better on harder woods. I do prefer a really fine burr for the shear scraping, which to me means 600 grit wheel or burnished burr. I don't think there is any possible to use a burnished burr on a gouge... I need to go back and compare the scraper burrs where I go straight to the grinder, then burnish that burr down and up a time or three. The idea being that when you burnish it down, it kind of breaks off so you have a fresh face to burnish on, and compare that to a scraper where I hone it off, and then burnish a burr.... More experimenting ahead....

    As to the 'more teeth/less teeth', I have no real idea. Some like the more coarse edge because the saw teeth work better/less teeth to wear down. Some like the more refined edge because more teeth take longer to wear down...... I have never had a 60 grit wheel to experiment with. I can't really tell any difference with my 80 and 180 grit CBN wheels, but a big difference when I step up to the 600 and 1000. Cuts more cleanly, but lousy for heavy roughing....

    robo hippy
     
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  8. john lucas

    john lucas

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    Zach When I did my sharpening test I sharpened to 2000 grit so the particle metal steels will take that fine of a sharpening. Glen Lucas uses a Tormek grinder to sharpen which is supposed to be 1000 grit. I don't know what tools he is sharpening however.
     
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  9. Zach LaPerriere

    Zach LaPerriere

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    Thanks for the comment. I'll have to try the Big Ugly Tool for roughing once I start rough turning again in the spring.

    I prefer the 60 grit CBN wheel for roughing, though the difference isn't huge. I bought the 60 grit just because the vast majority of the grinding I do is hogging off the secondary and tertiary bevels—I'm a Michaelsen grind fan.

    Even for roughing I much prefer the M42. I roughed with V10 3/4" gouges for a couple years before trying Dave's 3/4" U gouge. It's a fine machine, that gouge. The more vertical flute makes a fairly clean inside cut for such a large gouge, and the flute is wider than anything else I've seen.

    That is interesting, John. I'll have to buy that issue or a subscription. I'm curious what you sharpened to 2000 with.

    I ran a 1000 grit CBN from Ken Rizza for a year or so, but ended up preferring the edge from Dave Schweitzer's 800 grit wheel for both the V10 and the M42. I could speculate why, but at best, it's a wild guess. The grit does seem thicker on Dave's wheels—perhaps there is a difference in CBN grit cutting, just as there clearly is with sandpaper. On the other hand, maybe 1000 is just too fine...I really don't know anything more than my results.
     
  10. john lucas

    john lucas

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    Zack I used the scary sharp system with sandpaper glued to glass. I sharpened these tools to look more like a hand chisel but with a bevel on both sides like a skew. My goal was simply to test if the metal would take a keen edge. Would have been really hard to do with a bowl gouge. I ground the whole edge up through 600 grit and then increased the angle by 2 degrees and ground a micro bevel up to 2000 grit and then stropped the edge. I have found that stropping an edge really improves it. The yellow bars the carvers use works better on the particle metal steel than the green bars. The tool doesn't get any sharper with the yellow bar it just removes metal faster so stropping the particle metal took less time to get the same edge. For the final test I used the green bars on all steels so the comparison would be as accurate as I could get it.
    More Woodturning is a good magazine. They cover a lot of topics. Well worth the subscription in my opinion but then I'm biased because I write for them a lot.
     
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  11. Zach LaPerriere

    Zach LaPerriere

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    Thank you for the thoughtful answer, John. I will check out the article and the magazine. I'll do some playing around with and honing and stropping.

    I'm thinking you need to start calling your technique The Scary Sharp System™. That's a great name!
     
  12. Bill Boehme

    Bill Boehme Administrator Staff Member

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    I have seen the name scary sharp used for at least twenty years since woodworkers have been using sandpaper and belt sanders to sharpen tools ... mainly hand chisels and plane irons, although in some instances the word scary without the word sharp would have been a better description when a coarse belt sander was used. I first noticed the term used on the Wood magazine forum in the late 1990's when belt sander sharpening became popular.

    Too much stropping can actually decrease sharpness. The main objective is to remove any wire edge that exists and to slightly polish the bevel, but it's easy to slightly round over the cutting edge especially with a leather strop.
     
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  13. john lucas

    john lucas

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    Scary sharp is also kind of like saying razor sharp. I found out when doing these tests that there are definitly different razor sharps. Even the razors were different. For example I took a single edge razor which would easily shave hair and stropped it. It jumped 35 points sharper on the BESS machine. Still wasn't as sharp as the double edge razors that I have. I have a friend who has some scalpels. I may borrow one of those and test it. The name Scary Sharp started somewhere in the 70's I think when they started promoting using sandpaper on glass. This gave you a known abrasive and dead flat surface. Up to that point to get a really sharp plane iron you had to use water stones or oil stones and they had to be flattened occasionally and of course were messy.
    And Bill is right. Stropping and even honing can actually dull an edge of not done properly. One thing I'm learning with all of this is how important the sharpening angle is to the cutting action. Bear in mind this is purely cutting hair, paper, string etc. Not turning wood. A more acute angle cuts easier and therefore appears sharpers in these tests. When you hone or strop it's very easy to slightly round the edge which make the angle less acute and there fore doesn't cut as easily. That's why I use a concave grind so I can place the hone on the nose and heel of the grind and maintain an accurate angle so that I'm not rounding. However it's still easy to do so after I hone a bunch of times it's actually better to go back to the grinder and establish the original angle. How many times can you hone? depends on your skill.
     
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  14. Fadi Zeidan

    Fadi Zeidan

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    What grit do you guys hone with?
     
  15. Mike Johnson

    Mike Johnson

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    I have made a few straight razors over the years and use one to shave with on a daily basis.
    Using lapping paper / lapping film and a plate of thick flat glass you can get a "Scary Sharp"
    cutting edge on these blades. There are several YouTube video's that detail the proper process
    and the different grades of lapping film used to attain these edges.
     
  16. john lucas

    john lucas

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    I hone with a 600 grit diamond hone from Trendlines. It has 300 on one side and 600 on the other.
     
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  17. Zach LaPerriere

    Zach LaPerriere

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    Bill, you are absolutely right. I've been sharpening planes and chisels for much longer than I've been turning.

    A good friend who has been carving for 55 years is emphatic that you only sharpen at each grit for the bare minimum number of strokes necessary. Any more, according to Mike, is just an opportunity to dull the edge. The problem with this equation is that it takes a lot of experience to know just when enough is enough. But the remedy is easy: practice and time.
     
  18. Jamie Straw

    Jamie Straw

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    The advantage to the steel in the D-Way tools is not simply in the hardness (M42) but in the way they are processed. The tempering goes throughout the steel, and the tool is hung, not laid down on a surface. Sorry I can't give a more technical description than that, but my experience has been that they hold an edge longer and sharpen more consistently as the tool wears down, than the M2 steels I've used (Sorby, BB, etc.). Dave sharpens each tool by hand before shipping, if there's anything wrong with the tool, it doesn't ship, and when it's received by the customer it is s.h.a.r.p. :cool:
     
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  19. Bill Boehme

    Bill Boehme Administrator Staff Member

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    Since I usually use the Tormek to sharpen tools, I use 1000 grit to renew a cutting edge that is just slightly dull. Sometimes I stop there, but if I use the "honing wheel" which is really a stropping wheel, I use a white polishing paste which might be aluminum oxide ... Tormek doesn't say the grit, but it can be used to put a mirror shine on steel. The grit might be about 4000 if I compare it to the surface shine from Micromesh. When I first got the Tormek I didn't know any better so I thought that polishing the bevel of chisels and plane irons to a mirror shine was the thing to do and a sign of a very sharp edge. I finally figured it out ... a polished bevel might look nice, but the edge was gone. Just remove the wire edge and then stop. With really long bevels on skews and bedans you can polish the bevels a bit more for a slightly sharper edge.
     
  20. Bill Boehme

    Bill Boehme Administrator Staff Member

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    You've just about talked me into calling Dave and ordering a bowl gouge. He owes me a favor and promised me a good buddy deal a while back so maybe I can collect on it.
     

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