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  1. #121
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    Rob,

    I think we are in some danger here of "outrunning your coverage"... Regression data is generally not particularly good out past your data... Especially way way way out past the end of the data as we have here with the amount of wood cut to reach 500g dullness...

    The thing is - this interesting effect you found in your data is very cool and stands beautifully by itself... It illustrates that certain chisels have a really beautiful "feel" as they cut wood... But as a prediction model towards some level of performance above this - is probably way off.....

    Based on my own use of similar tools - the force goes down for a few cuts, stabilizes very slightly increasing for some number of cuts, and then starts going up after even more... At that point - those tools are miserably dull and require a huge amount of work to get them going again......

    But I do still commend you - as you are the first one who has published any data on tool performance in a long time... And in the end - it's your data and your study.

    But at this point - since you are talking about making your own chisels.... You need to figure out what drives successful performance. An interesting analysis at this point would be the classic Best of the Best vs Worst of the Worst to figure out what the main determining factors really are that you care about.

    So for example - do they cluster around Carbon content? Grain size? Alloy type? Etc....

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  3. #122
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    As to extrapolations, yes I agree. I've used a linear fit for simplicity, not accuracy. In the cases where I achieved 500 gm. of cutting force (interpolations) the figures reported are more or less reasonable. Where I didn't (extrapolations), especially where I observed the 'self sharpening effect' they reported values are reasonable only in that they tell me that these particular chisels hold their edges much better than do the chisels that dulled to my arbitrary 500 gm cutting force point after removing a gram or two of wood. Thus they serve only as very rough indications of the tendencies of the particular chisels tested to retain their keenness. My purpose is to guide my investigations. Those chisels that fail to hold their edges can quickly be excluded from further studies, greatly simplifying and lightening my burden. The data or extrapolations should not be interpreted as a buyers guide, except, maybe, in comparing the extremes. I also don't hold the measurements out as being representative of any particular manufacturer as I've only tested one 1" (or 24 or 26 mm as the case may be) chisel from each.

    Also it's important to keep in mind that I'm testing against pine. Not chopping but paring. The data I have allows me to sort the acceptable from the unacceptable. I doubt that many woodworkers are looking for a bespoke pine paring chisel.

    Marples, Sorby Bench, Narex and all of the other chisels that quickly dulled are going to be dropped from the next series of tests on harder species of timber. In the case of these chisels the fitted lines don't matter, they all dulled quickly under the least demanding woodworking conditions aside from resting in the hands of a collector.

    I'll attempt to remediate some of the losers to see if it's possible.

    My central purpose in doing this work, as originally stated, is to try to use these sets of chisels and the data I can gather to gain some insights into the characteristics that make for a good chisel. I really don't care of the ranking of other commercially available chisels because I will never make or try to reproduce any other brand of chisel, they are test articles (tax deductions too) to me.

    I'm not equipped at this point to examine metallurgical characteristics of these chisels beyond hardness. I can however take known, assayed alloys, process them, and determine their performance and pick the best practical chisel - my real goal.


    At this point I've made the following more or less firm observations:


    • Hardness isn't necessarily the primary determinant of chisel performance, much as I've observed in my studies of saws.
    • Included angle makes, maybe, a little difference.
    • Price is no guide as to quality in commercially available chisels, of this point I'm certain.
    • In sharpening jigs, ultimate sharpness is proportional to wheelbase and or mechanical stability.
    • Most commercially available sharpening jigs can't make use of the sharpening potential of stones > 10,000 grit or so, their wheelbases are too short , they're too unstable, or both.
    • The fishing line cutting method, despite it's obvious limitations, works well enough and can be (and has been) improved significantly. More details later .


    The data I've acquired suggest that the makers of Lie Nielsen, Craftsman, the three Japanese marks and potentially Lee Valley chisels know what they're doing.

    Next step is to take the winners from this series and test them against harder wood. That effort begins tomorrow.
    Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.

  4. #123
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    Quote Originally Posted by Bushmiller View Post
    Bob

    Does that sound the death knell for face to face lectures in the future?
    Paul and Bob,

    If I may be permitted to butt in, I think that Kapital has finally achieved the position in Western society that it is the sole arbiter of worth. As such, individuals who do not serve the needs of Kapital are, by definition, surplus to it's needs and of no interest. (Anybody have a Karl Marx emoticon?)
    Why pay a professor if you have a recording of a professor? Why have lectures and lecture halls and a campus if you can offload the cost onto the students via making them buy the course, the computer to watch the lecture on and the internet service? Youtube U anyone?


    Quote Originally Posted by Bushmiller View Post
    Rob

    Sorry. I promise no more digressions.
    I don't want to give lectures or monologues, I want to have conversations so digressions are welcome .

    Quote Originally Posted by Bushmiller View Post
    Back on topic. Are you at a stage where you are going to embark on chisel making but if not, how much further will you need to test and investigate existing brands? I am rather interested in seeing a new chisel maker emerge.

    Regards
    Paul
    Soft wood leg of these studies is now done.

    I know some of what I need to know and have significantly narrowed the field. Poor performers in pine paring are not going to be good performers in harder timbers and thus the field of chisels is narrowed by almost half.

    Narex, Marples, Sorby bench and Berg are out. The Blue Spruce paring chisel will be carried forward as a standard comparator. The other Blue Spruces will be ground down some to probe the decarburization question. If they don't get appreciably better I'm going to try cryo-treating them.
    Lie Nielsen, Craftsman, Sorby firmer, Pfiel butt, and Lee Valley PM-V11 and the three Japanese chisels are in for the next round.

    I'm thinking about either oak or hard maple as the next test species, any thoughts?

    Rome wasn't built in a day. Once I have what I think is the best recipe I then need to tool up to make them in commercial quantities with boutique tool level fit and finish, could take a bit.

    Regards,
    Rob
    Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.

  5. #124
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    Quote Originally Posted by rob streeper View Post
    I'm thinking about either oak or hard maple as the next test species, any thoughts?
    I agree with those, maybe Hickory or Merbau as well for something a bit closer in hardness to Aussie timbers like Jarrah and Blue Gum?
    Apparently Cocobolo is somewhere between Spotted Gum and Ironwood on the Janka scale, but probably a bit too expensive. Wikipedia says that strand woven bamboo flooring is a similar hardness

  6. #125
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    Rob

    As far as timbers go, I would suggest something that is commonly used in the US and not necessarily any extreme timbers. Whilst I would like to go along with EJ on replicating the hard Aussie timbers with something on your side of the pond I don't think that is realistic or indeed necessary if you are ultimately to appeal to your primary market (always assuming that you go semi-commercial at some point.) I think you need to stick with a timber your market recognises and is commonly available. Hard maple fits that bill I would think.

    You can always do a supplementary trial on some exotic piece of timber as "more proof" and when trying to win over the hard bitten Aussie types . I think that even at this early stage you have to envisage your market. Probably it is the enthusiastic woodworker who really likes his hand tools. What are their timbers of choice in the US? Hard maple for the harder timber and Cherry (?) for a softer timber perhaps. Of course, if you just happen to have enough Cocobolo lying around, use that too.

    Regards
    Paul
    Bushmiller;

    "Power tends to corrupt. Absolute power corrupts, absolutely!"

  7. #126
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    I rummaged around in my scrap bucket and found some pieces of hornbeam. I was originally thinking of Argentine lignum vitae but it's not really the kind of wood one thinks of using a chisel on. I'll work on oak today, I have a nice piece of tongue and groove flooring that came out of a hundred year old house.
    Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.

  8. #127
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    Quote Originally Posted by rob streeper View Post
    I rummaged around in my scrap bucket and found some pieces of hornbeam. I was originally thinking of Argentine lignum vitae but it's not really the kind of wood one thinks of using a chisel on. I'll work on oak today, I have a nice piece of tongue and groove flooring that came out of a hundred year old house.
    Hi Rob
    I seriously question the suitability (?) -- advisability might be a better term -- of using hornbeam or even 100 year old oak flooring.

    May I suggest a more appropriate wood might be Maple and/or Cherry. These are common cabinet hardwoods in your neck of the woods and should provide a representative test. Using a harder, tougher species might possibly skew your results away from where you want to be.

    As I understand your purpose, you ultimately want to make a chisel that "works".

    My own view is that somewhere in the process you will need to define what "works" really means.
    A comment, from perhaps 15 or more years ago, that has stuck in my memory reflected on students graduating from the North Bennett Street School in Boston. Those who left the school with a set of oldish or conventional steel chisels know how to keep their chisels sharp -- they were proficient because they had done it so frequently -- those who left with a set of LN A2 chisels know what sharp is, but didn't know how to sharpen sharpen -- they were not proficient because they had done it so infrequently.
    reflecting on this, a definition of "just works" will, along with the duration of the edge, incorporate some measure of the ease of sharpening -- which might well be subjective based on your own prejudices. Is sharpening a necessary chore, a delightful interlude, or somewhere in between?
    regards from Alberta, Canada

    ian

  9. #128
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    Quote Originally Posted by rob streeper View Post
    Soft wood leg of these studies is now done.

    I know some of what I need to know and have significantly narrowed the field. Poor performers in pine paring are not going to be good performers in harder timbers and thus the field of chisels is narrowed by almost half.
    This is not my experience.
    without meaning to assert that my technique is optimal, what I've found / observed is that a chisel (or plane blade) sharp enough to pare end grain hardwood, can be hopeless in softer timbers.
    using a #9 as a shooting plane, if I switch between hardwood and pine (or cedar), what was an end grain shaving in one becomes end grain dust in the other.
    I don't fully understand why, but believe it has something to do with the variation in hardness between early and late wood in softwood species and/or the tightness of the grain.

    Likewise, I've observed a correlation between chisel bevel angle and the ability to take end grain shavings. The steeper bevels recommended for some steels perform poorly in pine, while shallower bevels don't seem to like harder woods. If I were at home I'm confident that I could pluck a chisel from the "collection" that will fail to shave end grain pine, while performing adequately with end grain hickory.
    regards from Alberta, Canada

    ian

  10. #129
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    While it matters little across all of the hardwoods, the ring count, the growth rate, in the conifers has a profound effect on carving properties.
    Including what you expect to do with your chisels as a definitive character.

    I have been carving mostly western red cedar (Thuja plicata) for maybe 2 decades.
    A little yellow cedar (Chamycyparis nootkatensis) and some paper birch (Betula papyrifera.)

    Start shopping with a ruler. Good cedar has an annual ring count of 15-40 rings per inch.
    Less is punky soft crap that you can't cut with a chisel, no matter how good you are with sharpening.
    40+ gets pretty boney but ought to suit your purposes.

    I have bought that WRC crap by accident. Beautiful clear, straight grained, a carver's dream-wood.
    That's how I learned, all of a sudden, about the money I wasted. 6-10 rings per inch.
    OK, and it applies to spruce and pine and fir and Douglas-fir/Oregon.

  11. #130
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    As Ian notes, my experience is similar... Soft wood and hard woods are two different beasts WRT chisel performance.

    With soft woods a keen edge that doesn't roll or chip is king...
    With hard woods - that ultra keen edge doesn't matter nearly as much.. A chisel will cut oak or cherry just fine way beyond the point where it won't cut spruce at all... That's one of the reasons HSS is so heavily favored down in Australia - where it seems like all they have is hard horrible stuff like Gidgee, Wandoo, Jarrah, and super hard sorts of gum... In the US it's different - most of the hardwoods woods fall in with cherry, maple, birch, and oak - which work just fine with normal steels...

    In terms of studies.... It seems like quite a bit of work has been done - many makers are doing really good things... So the knowledge exists... But it appears that the knowledge which didn't die out with the blacksmiths and job shops in places like Sheffield is living in the realms of tradition and trial and error... Unfortunately not much of it appears to be published......

    I don't think it's any coincidence that good chisels are made with fine grained steel that falls out between 1% and 1.5% carbon...

  12. #131
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    Smoke and mirrors when it comes to conifer wood carving performance.
    Ring count is everything and I have a couple hundred dollars in the toilet to prove it.

    If it is your intention to compare hardwoods and soft woods again, I expect you to define the ring counts.
    Then, correlate that with the Wood Data Janka hardness. This is gum nuts and bananas.

    Look at the wood anatomy in each ring, the difference and the width of the early wood and the late wood.
    What I see and carve is 20-30 rings/inch. It is absolute pleasure to work.
    Yeah, what have you got? Coastal Western Red Cedar or interior WRC?

    Professor Brian W. Thair, PhD LaTrobe Botany 1972

  13. #132
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    You could also use some of the manufactured wood as a constant so it removes variabilty between pieces.

    Sent from my SM-G950F using Tapatalk

  14. #133
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    Quote Originally Posted by Bushmiller View Post
    Bob
    Does that sound the death knell for face to face lectures in the future?
    Well they have cut back on everything so no doubt.

    Worse still has been the cut back in lab experience.
    We had 13 weeks x 3hours per semester.
    These days its 12 weeks at 2 hours every fortnight so 12 hours versus 39 hours.

  15. #134
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  16. #135
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    Quote Originally Posted by Robson Valley View Post
    While it matters little across all of the hardwoods, the ring count, the growth rate, in the conifers has a profound effect on carving properties.
    Including what you expect to do with your chisels as a definitive character.

    I have been carving mostly western red cedar (Thuja plicata) for maybe 2 decades.
    A little yellow cedar (Chamycyparis nootkatensis) and some paper birch (Betula papyrifera.)

    Start shopping with a ruler. Good cedar has an annual ring count of 15-40 rings per inch.
    Less is punky soft crap that you can't cut with a chisel, no matter how good you are with sharpening.
    40+ gets pretty boney but ought to suit your purposes.

    I have bought that WRC crap by accident. Beautiful clear, straight grained, a carver's dream-wood.
    That's how I learned, all of a sudden, about the money I wasted. 6-10 rings per inch.
    OK, and it applies to spruce and pine and fir and Douglas-fir/Oregon.
    I have three sets of cedar sliding closet doors, they're about 36" wide and 80" tall. Almost perfect bearing their original orange lacquer except the goof who owned the house I took them out of painted one of them. The wood is about 90 y.o. and feels more like maple in density. Still waiting to find a good use for them.
    Innovations are those useful things that, by dint of chance, manage to survive the stupidity and destructive tendencies inherent in human nature.

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