"Romance to Natural Stones"
Isn't this a bad 80's movie?
"Romance to Natural Stones"
Isn't this a bad 80's movie?
Simon; appreciate your feedback on A2 steel.
regards Stewie;
L-N's A2 is pretty good stuff. It's cryo-treated and long-wearing even as A2 goes, though not quite up to the level of PM-V11 in that regard. I have L-N #8, #2, and #10-1/4 planes, and they worked OK grinding at 25 and honing at 30 back before I moved to higher edge angles on my common-pitch planes.
As noted in the other thread A2 prefers higher angles like any high-alloy, non-PM steel though IMO anything over 30 deg is acceptable for most uses.
It's like a "romance" with an abusive partner that takes all your money and won't let you hang around with any of your old high-alloy friends, but it feels so good when you "sharpen your blade" so it must be right...
So I have a curiosity question: What do Japanese woodworkers use to sharpen their Blue Steel tools? Based on composition that stuff has to have nontrivial Tungsten carbide content, and the Silicate abrasives in JNats aren't going to work so well on those.
Last edited by Patrick Chase; 06-13-2016 at 10:57 AM.
I sharpen blue steel 1 & 2 along with exotic alloys like Togo Kou (modern Togo Regiou) with natural stones. I'm getting clear edges. I also sharpen extremely hard white steel 1 and Assab K120 with the same stones.
A2 always appears to have an eroded look when worked with natural stones, that same issue in not the case with the steels mentioned above.
Often it is right on the edge of being able to cut those steels.
Bumbling forward into the unknown.
George,
I expect not many. A sure sigh it may be time to shuffle off stage, visit the Tijuana Farm and Ranch store, do a Thelma & Louise, is when you have to explain all your cultural references. I've been doing it for a few years now, sometimes my clients look at me with the "what is this old fool talking about now" look. Sometimes I tell 'em to suck it up, may you live so long.
ken
To be clear the problem here isn't average hardness, it's homogeneity or lack thereof. I'm not surprised that super-hard White 1 works because that stuff has almost no carbides and is therefore uniformly hard.
The problem with A2 is that it has ~5% Cr, and the resulting Chromium carbides have hardness well in excess of Rc70 even when the average hardness of the alloy is tempered to typical A2 values of Rc61 or so. Those carbides are large enough that you get noticeable edge dulling if the sharpening medium chips/erodes them out instead of honing them.
After thinking about it some more I think I understand why Blue Steel works: Tungsten tends to form finer grain structures than Chromium, and Blue only has ~2% W to begin with. The resulting carbides are Rc75+, but they're probably small enough that chipping/eroding them out during honing doesn't result in a detectably dull edge. It would be interesting to see what's going on with an SEM though.
"Small carbides" are also why PM-V11 hones acceptably on natural stones. It appears to have wicked high Cr content (more than D2) but PM processing shrinks the individual carbides to the point where it isn't a practical issue.
Last edited by Patrick Chase; 06-13-2016 at 12:44 PM.
Hi Ken
I read sharpening threads with a mix of curiosity and bewilderment. Perhaps I am being over-simplistic here, but the aim of sharpening is to create two intersecting, polished edges. The only issue is that some media are better or less suited to certain steels. Everything gets abraded with diamond, but diamond does not polish well. Choose the poison you prefer. Just ensure that it abrades the steel you use, and that you can polish to the level of smoothness you prefer.
This way, A2 will certainly get as sharp as anything else. That is not to say that the edge is the equal of O1 or PM-V11. In theory, the larger carbides in A2 can leave a serration. In practice, I obtain excellent surfaces in hard woods. The woods in Australia are hard, interlocked and abrasive (high in silica). Edge holding is a high priority for me since a dull blade will more readily lead to tearout. For this reason, O1 is risky to use. I have replaced many of my blades with PM-V11. This has greater durability than A2 and a similar (better?) smooth edge than O1.
Your softer and straighter-grained woods are not demanding at all. You can use O1 happily all day long. The only issue for you is that softer woods will show up any shortcomings in sharpness. Fortunately, O1 can be sharpened by just about anything.
Regards from Perth
Derek
Ken, if you have not yet moved on the new plane Iron I'd second Tony's tip on the Ray Iles. I only have one of their irons, it lives in a Stanley 78 Knockoff where the original iron supplied was super soft. Honed up very nicely on an oil stone and works very well.
I think the reason for the disconnect is because there's a second issue that you're consistently ignoring even though it's been repeatedly explained:
Every steel has a critical angle below which it can't be honed without unacceptable wear during use, due to edge-chipping. D2 is infamous for requiring high honing angles to avoid chipping, and A2 is problematic as well. Note that the sharpening medium does not matter as much in this context - even if you hone the edge perfectly, the carbides in the edge will still be vulnerable to chipping due to their weak attachment to the surrounding metal. This is why the straight-razor crowd don't use A2 or any other high-alloy steels.
I can buy that in your specific case you may not see this as a significant issue. If you're bashing away on "impossible woods" all day then low-alloy steels will probably be so vulnerable to conventional dulling and edge-folding when honed to low angles (<30 deg) that the chipping issue with A2 might not look like much of a problem. That doesn't in any way invalidate what other people are saying about what happens in *their* use cases as you seem to suggest above, though.
Last edited by Patrick Chase; 06-13-2016 at 11:56 AM.
Cool, would be good to hear your thoughts, you don't find much user feedback on them.