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  1. #16
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    To confuse things a little, IME a good quality HSS ground on a diamond or CBN wheel gets more of a burnish straight off those wheels compared to Alox.

    Burnishing is just consolidating the edge with a harder material. A consolidated edge will last longer than a fragile ragged edge.

    Hand burnishing with a diamond plate both raises and consolidates the edge at the same time. I tend to do this several times before going back to the grinder.

    Sent from my ZTE T84 using Tapatalk
    Stay sharp and stay safe!

    Neil



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  3. #17
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    Quote Originally Posted by rtyuiop View Post
    Haven't spent much time in the shop lately (too hot!) but I finally got some experimental sheer scrapers made and had a quick play around with them - these are what I was mucking around with:





    My observations (all based on experience with an australian cedar bowl I was playing with):

    Tried a very 'blunt' grind first -my normal scraper angle, ~30 degrees but done on both sides, so maybe a 120 degree angle in the end - could barely get it to cut, so went to ~45 degrees on both sides for a ~90 degree point, which was much more satisfactory.

    Raising a burr with a burnisher (timberbits and their 15% off sale ended up being expensive!) was probably the single biggest factor I saw in how effectively they cut, outside of technique. Going to have to practice using the burnisher on a rounded tip tool though!

    The round blank with a rounded tip chisel (the middle one in the photos) was by far my favourite. The square tips made things very dependent on tool rest height being exactly right, and the square blank meant I couldn't alter the angle easily. The round tip and round blank also meant I could 'tune in' angles vertically, horizontally, and how the chisel was rotated. I could also cheat with my sharpening, and if the burr had gone on one part of the blade, just start cutting with another area.

    I do think the other shapes might be better suited to spindle work, but not sure if they would be superior in any way to my normal combination of a skew and some traditional scrapers.

    So - long story short, I really like the combo of a burnisher and a round chisel with a rounded, 90 degree tip. Bear in mind this was all of a couple of hours playing around, and all on one bit of wood, so my current opinion might be completely wrong in other circumstances!

    Cheers,

    Danny

    Well mate, all I can say is that they have to be the strangest looking scrapers I have ever seen.
    Do you use them with the flat side resting on the tool rest?.
    Blimey, the one on the right hand side,first pic, looks like a dovetail chisel.
    Also the angles people have mentioned are a bit ambiguous. 90 degrees is 90 degrees. However 80 degrees is also 10 degrees and 20 is 70 depending how you read it.
    Here is a picture of some of my scrapers.
    DSCF6673.jpg And hopefully a sort of side on pic of a few of em to show approx grind angles DSCF6676.jpg.
    I like to use the burr that the grinding wheel makes when you sharpen them. I know how to put a burr on a cabinet scraper with a file then a bit of tool steel but to sharpen my turning tools like that would drive me batty.
    When you have a heap of turning to do a quick sharpen is a must and the grinding wheel is where to go. I am sure you could manually put a burr on those turning tools as well but it comes down to time with me.
    My long departed step father could not believe that I ground a tool on the grinder each time it needed sharpening when I first got my lathe. He was a product of the depression where nothing was wasted and preferred to somehow hone the scrapers on a stone to prolong their life, until he did the woodturning course that I'd done. He was a grinder after that.
    Anyway, you may notice that all my scrapers have a flat bottom (that rests on the tool rest) and top surface. Not saying this is how you "must" do it, but it works well for me.

  4. #18
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    artful_bodger - yeah, these are specifically only for sheer scraping (with the edge at an angle to the tool rest), I have normal scrapers for non-sheer scraping.

    For sharpening - I just grind my normal scrapers (although I must admit I will be trying burnishing them for finishing cuts in the future after what I saw with playing with these!), but for I'd only ever sheer scrape for light finishing cuts, so raising a burr away from the grinder won't take an inordinate amount of time - won't be removing much timber so hopefully won't have to do it all that often...

    Danny

  5. #19
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    Quote Originally Posted by rtyuiop View Post
    artful_bodger - yeah, these are specifically only for sheer scraping (with the edge at an angle to the tool rest), I have normal scrapers for non-sheer scraping.

    For sharpening - I just grind my normal scrapers (although I must admit I will be trying burnishing them for finishing cuts in the future after what I saw with playing with these!), but for I'd only ever sheer scrape for light finishing cuts, so raising a burr away from the grinder won't take an inordinate amount of time - won't be removing much timber so hopefully won't have to do it all that often...

    Danny

    Well there you go, you learn something new every day. Once accidentally bought one of those round bottom sheer scrapers off ebay thinking it was flat both sides. Threw it out when it arrived, never seen anything like it before. Ha Ha.
    Do sheer scrapers work THAT much better than the regular ones which seem to work fine to me?. What are the advantages of them?.

  6. #20
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    Quote Originally Posted by artful bodger View Post
    When you have a heap of turning to do a quick sharpen is a must and the grinding wheel is where to go.
    Looking at your collection of scrapers there, Artful, I guess you could say you are 'scraping' out a living!

    Sent from my ZTE T84 using Tapatalk
    Stay sharp and stay safe!

    Neil



  7. #21
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    Quote Originally Posted by artful bodger View Post
    Do sheer scrapers work THAT much better than the regular ones which seem to work fine to me?. What are the advantages of them?.
    Yes, particularly, when coming up the inside of a bowl through the end grain.

    You don't have to use a round bar to shear scrape. Just roll any scraper onto its side and you are shear scraping.

    You may need to add a chamfer to the edge that sits on the tool test (the way good skews have that) to avoid it digging into and dinging your tool test.

    If you don't have a round bar scraper, a bowl gouge rolled over with the second edge close to but not touching is also good for shear scraping, particularly on the outside of bowls, but also works for some areas on the inside like the end grain.

    Start with a 45deg angle to the horizontal and use very light cuts.

    Sent from my ZTE T84 using Tapatalk
    Stay sharp and stay safe!

    Neil



  8. #22
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    Yeah, it really does make a difference on timber that’s prone to tear out!

    I find myself sheer scraping (before these dedicated tools I’d use either a normal scraper on edge or a bowl gouge, as NeilS mentions) for finishing cuts on things like aust cedar or even US walnut.

    Cheers,

    Danny

  9. #23
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    Quote Originally Posted by rtyuiop View Post
    Yeah, it really does make a difference on timber that’s prone to tear out!

    I find myself sheer scraping (before these dedicated tools I’d use either a normal scraper on edge or a bowl gouge, as NeilS mentions) for finishing cuts on things like aust cedar or even US walnut.

    Cheers,

    Danny


    Well, best I go an peruse youtube to find out more about these "sheer scraper" things.

  10. #24
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    AB. You might like to have a look at thus clip by Reed Gray. Its the one that got me interested in shear scraping.
    https://www.youtube.com/watch?v=xeOh...2tkj0hw03c010c

    Like a lot of other techniques related to wood turning its never quite as easy as a pro makes it appear.
    Funny how I have been turning for nearly a year now and had never heard of shear scraping until I saw this vid then hear that a whole heap of other turners are using it. Make me wonder how many other tricks that the more experienced turners have up their sleeves that they aren't telling me about.

    Tony
    You can't use up creativity. The more you use, the more you have. ~Oscar Wilde

  11. #25
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    Minor update on this topic...

    Out of the tools pictured earlier in the thread, I don't often use either the round shaft with a straight grind, or the one with a square shaft - I think they'll be reshaped to something else when I need the something else.

    The round shaft with a rounded tip has become one of my go-to tools (always hitting it with the burnisher after sharpening), so much so I added something similar to the tool set recently - wanted something bigger, so got a 5/8 spindle gouge blank with a shallow flute, and reground it so the flute is irrelevant (if I could have gotten a plain round 5/8 blank I would have!):





    Gave it it's first run this week, working very nicely - the bigger blank gives more edge to use before it needs resharpening. Still haven't decided if I'll leave the top ground flat or will round it like the bottom...

    Cheers,

    Danny

  12. #26
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    I tend to grind mine so that the plane the cutting edge lies in is parallel to the tool axis. (ie. the same as a profile on a bit of flat steel stock) This usually means a curved grind on both top and bottom.

    That way, no matter which part of the cutting edge I'm using (I like to "use all the sharp bits" before heading back to grinder ) it's still cutting at around the same angle so long as I don't make a major changer to the tool presentation.

    Looking at the side pic of your tool, this plane is angled nose down, so there'd be quite a difference between cutting in the centre and cutting on either wing..

    Not so important when you can keep eyes on the job, but when you're working blind in hollow forms or undercuts this sort of thing makes life sooo much easier.
    I may be weird, but I'm saving up to become eccentric.

    - Andy Mc

  13. #27
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    Yeah, I think I am going to regrind to that shape - was using it yesterday and having to track the angle of the cutting edge as you change the section you're using is a pain!

  14. #28
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    Discovered another great use for the sheer scraper above - finishing cuts in corners of boxes. Because of the shape you can get really deep into a corner... Being super careful to cut with the tip, so that the upper edge of the tool doesn't touch the 'other' surface (the one you're not cutting) and catch!

  15. #29
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    Quote Originally Posted by rtyuiop View Post
    Discovered another great use for the sheer scraper above - finishing cuts in corners of boxes. Because of the shape you can get really deep into a corner... Being super careful to cut with the tip, so that the upper edge of the tool doesn't touch the 'other' surface (the one you're not cutting) and catch!
    That is how Richard Raffan and Benoit Averly do the inside of their boxes. First they do the inside out hollowing cut that Richard perfected with the gouge, viz.


    They are cutting in both in and out directions. That video clip is not sped up! Then they clean up the bottom corners with a scraper. The outside is completed with a skew. They complete the whole box and lid with a perfect suck fit in less than 10 mins. Benoir is faster than Richard now, but he learnt the technique from Richard.
    Stay sharp and stay safe!

    Neil



  16. #30
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    If only I were that good with a gouge!

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