Hand Tools

Subject:
Familiarity with the oven
Response To:
Compare and contrast ()

david weaver
I can get to within 10-15 degrees in the oven. How do I know? I have to put the irons in a particular spot in the oven, and then check them periodically with a non-contact thermometer. If I were to start moving irons around in the oven and not putting them in the same spot on the same setting, I would have errors that were more like 50 degrees plus.

Where I can gauge hardness is with stones, reasonably well. Perhaps less well with V11. I think I can still easily guess within two points. I'd say the iron that i sent wiley is probably 60-61 hardness. it would be interesting to have an iron like that tested, but I don't think it's important. The detail where the easing is important is in making an iron that's hard to finish sharpen on a certain stone suddenly finishable in that zone without too much loss in longevity.

Washita is right around 62 hardness, as is about 85% of the abrasive in a japanese natural stone (they do generally have about 15-18% natural aluminum oxide from volcanic ash, and can be stronger cutting than novaculite because of it - but that's a density much lower than synthetic stones. The grit in a good natural stone is relatively uniform - actually very uniform - but even if the alumina particles are uniform, the rest of the stone may not be.)

Back to the hardness - small changes in the above-60 hardness area make for big changes with how the final honing behavior is on a stone.

I hollow grind shallow and then freehand a secondary bevel on an iron, never working that much material. Someone who wanted to freehand a single solid bevel on the iron that I sent wiley would still find it challenging.

I sometimes forget that I've gamed my honing method to be doing very little with the finish stone so that I don't have to remove errors from it on the next sharpening, and so that I'm not dependent on "fast" finishing stones. Wiley's discussion of the grinding still being a little slow rings true - it's also true on a high speed grinder. Grinding is probably half the rate of carbon steel and with far less spark, so there's less to observe other than feel.

(my oven is also convection, so a particular spot tends to stay in a narrow range, even though the entire oven doesn't. I just need to know the setting and the spot and not deviate. I've done that in the past).

Years ago, George Wilson was coaching up some beer leaguers on SMC and telling them to get a reliable toaster oven to do this instead, OR, to get a decent oven thermometer and run their oven first without anything in it and put the thermometer at a given spot and observe. That's what I did initially.

There is a bigger variable for me, though. By color, I suspect I can't reach the top of the range for V11 before quenching. trying to attain it and keeping the metal at high heat in the open atmosphere to chase another 25-50 degrees is, I think, a bad thing. Am I getting 1850 or 1900 at a very bright orange? I don't know. By color charts, it's not 2000. that's a minus for my hardening in terms of initial hardness, but some patience still finds a 350 degree temper too hard for my taste. Probably at least as hard as the LN iron. 400-415 is slightly softer than LV's iron. 1 point or two? I don't know, but it's not 4.

Hardening in oil as opposed to in moving air or plate hardening is a plus 1 for hardness more or less, and not cryo tempering is a minus 1.

Add that all together, and if LV is hardening with air or plate hardening, I'm up plus 1 for the oil. If they're cryo tempering, plus one for LV and were back at zero, and if they're quenching from the top of the heat range instead of mid or bottom, they're up another. They may be able to attain an extra point.

I don't know if wiley will compare to the two, but I suspect my iron will be slightly sweeter to hone on his japanese stones than the LV. It's not going to feel hard, and it's not going to feel soft. It won't blacken the swarf as fast as carbon steel.

I fiddled with this a little bit because I just don't want to give up the natural stones. It's not essential that you do with a V11 iron, but drop them back a point or two and sharpening goes from tolerable to pleasurable.

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