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Thread: Plane blade expectations

  1. #31
    Join Date
    Feb 2004
    Location
    Perth, Australia
    Posts
    9,467
    Kees, I suggest you re-read the earlier post I made.

    Regards from Perth

    Derek

  2. #32
    Join Date
    Jun 2018
    Location
    Moscow, Russia
    Posts
    49
    IMG_20181027_185506.jpg
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    That's some frustration exercise, I'v just got two honed blades chipped in 5 minutes. All PM-V11 in the same BU jack.

    Overall I have 3 blades, honed to 25*. First one that I have no questions to was in the plane for long time and I prepared almost all stock for saw bench. Then I got to a board with large knot and realized I need sharper blade. So I dropped in fresh blade and flattened one side. That happened to be the blade I was talking about in the start of the thread. After one side it got chipped all over the edge! I'm super suspicious about that blade.

    Ok, I dropped in another fresh blade and flipped the board. After flattening I got edge chipped in one place. Frustrating.
    Well, chipping in one place I might understand. I even found some wood filler later on that board face. Probably that's the filler or some sand got into it.

    Third blade is magnetic, by the way. Why is it magnetic, is it common or not? I thought it is expected to de-magnetize during hardening and also magnetic properties might be nasty during sharpening...

  3. #33
    Join Date
    Sep 2007
    Location
    Longview WA
    Posts
    27,347
    Blog Entries
    1
    Knots do nasty things to any blade. Some pine knots are harder than lignum vitae.

    jtk
    "A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
    - Sir Winston Churchill (1874-1965)

  4. #34
    Join Date
    Jul 2017
    Location
    Calgary AB
    Posts
    179
    Firstly, the non magnetic state during hardening is at temperatures literally 1400 degrees (Fahrenheit) higher than your normal day to day house temperature. It is temporary since the steel returns to "normal" temperatures. All normal steel will stick to a magnet. Things get magnetized. Also normal. Not too hard to live with. People used magnetic racks to keep their tools, knives etc up on the wall. All of these items have been through heat treatment. Still sticking just fine.

    What sort of bevel situation are you at? actual micro bevel at 25*? Or attempting to polish the whole bevel at 25*? The latter is hard to pull off considering the hardness and wear resistance of PMV-11, and the width of the bevel at 25*.

    Why are you trying to prep boards like that with a 25* blade anyways. Some of my edges for end grain don't even need to be that low. Only creating more effort for yourself in terms of sharpening. 25 for stock prep is fine if you're okay with the inevitable quick edge damage that will come and especially when you run into a knot. Jim state that his irons show similar chipping when running into knots. All this and wood filler or even sand; it's like you're actually trying to kill the edge.

    The first plane I bought was a BU jack. It's first task was to prep many many pine boards like yours. More knots, no varnish or sand though. I was running to the stones more frequently then I liked, but I wanted to keep that 25*. Eventually I had to give in. Raised the bevel to a more appropriate angle and things started clicking. Years later the bevel is now slightly higher as I usually plane very interlocked grain often but I keep low angle 25* blades for the appropriate tasks. Derek mentioned that at 25* the blades are fine; this is absolutely true, and true of any bevel in the normal sphere of accepted bevel angles. Yet every bevel has its own performance and life balance, A 25* bevel is very nice for effortless end grain work or face grain planing, until it wears beyond it's capabilities. A 50* bevel is very nice for smoothing some hellishly interlocked grain, yet not as effortless as a 25* bevel when you try to shoot some end grain with it. There is a relative balance one must be aware of.

    On Derek's site, there is a comprehensive writeup of shooting planes and their blades. Probably one of the few objective ones of its kind; at least with this level of depth. A test with a 25* PMV-11 blade is included. You can see how after 60 strokes there is a little amount of visible wear, the blade is still quite capable of going through more end grain but the wear is now noticeable, with a few faint lines apparent on the end grain of the board used as the test piece; a sign of this little bit of wear. Now note that this was 60 strokes through a 6 inch width board 21mm thick. Now look at your situation. 60 "strokes" on a board where the strokes are cutting through much more material; face grain and knots; this is a lot more wear. The knot on your board by itself is a similarly sized area to the end grain of the board in Derek's test. There's more than one knot and a whole lot more face grain. So we've established this one pass on your much larger board is much more wear on the blade, and you are probably trying to take thicker shavings. Now in 5 minutes I can take many more passes then 60, Im sure you can too. Go to Derek's site and take a look at the wear from 60 strokes on a piece that small and then look at the size of your board and the amount of passes you take in comparison. I'm sure things will click. You should be able to visualize how much wear will quickly form on your blades especially with every pass that hits a knot. I haven't even included the sand or wood filler as a factor yet, these are incredibly damaging to the steel. I have Stanley plane blades lying around which are ruined from some truly heinous tasks that include planing materials containing these sort of things. Lots of grinding and rehab needed to remove the steel where the abrasives have left deep scratches into the back of the blade. If you hone and strop often that will certainly help.

    I think there have been at least four separate posts to this thread specifically stating the importance of good sharpening practices and or frequent sharpening. I will echo these here again. Also, all damage must be removed 100% or you will just get accelerated wear again. This level of damage on your blades would take some effort on stones, and a 25 degree bevel grows big rapidly. Which means even more time needed honing. Which means if you are stopping prematurely on the lower grits you are allowing the remnants of wear to just accelerate rapidly once you start planing again.

    Please take the time to read this post and have a look at Derek's writeup http://www.inthewoodshop.com/ToolRev...tingPlane.html
    And take the few seconds to compare his pictures and their content and the board/situation you're in.

    If you make actual changes this time and then significantly short edge life is still a problem then you can take a look at the possibility that the blade itself is the problem. However this is very unlucky, LV is not an unskilled worker staring into a roaring coke fire guessing a range of temperature and time and pulling the blade out and quenching in some carcinogenic automative fluid. The steps/temps/soak time required to harden the more highly alloyed steels serve almost as an increased QC measure. But sometimes a couple slip out, miss tempering, who knows. Highly doubtful though. Contacting LV is the quick way to rectify this, but do take a look and change some of your practices and/or expectations before leaping to this conclusion. I have no idea why you would expect a blade to survive repeated encounters through knots like that and with a 25* bevel no less.

    Best of luck,

    Vincent

  5. #35
    Join Date
    Jun 2018
    Location
    Moscow, Russia
    Posts
    49
    Ok, seems asking questions at sawmillcreek might be frustrating as well

    Although I like Veritas and using their tools is mostly pure joy, pitfalls might happen. I had bad experience with one blade that was replaced by axminster. Since it was international delivery, axminster didn't request return for the blade. I contacted LV directly and sent them that blade upon my expense. Later I got confirmation that there was some problem with metal.

    To whom it may concern, I'm going to contact axminster regarding that blade as well. This blade is way below expectations and cannot be compared to its twins. Now I have all blades marked so I can track their performance.

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