I land the technique, measure later...
David Weaver
..when someone asked how far off the cap iron is set for close planing, I said "put it as close to the edge as you can visibly see anything at all in light and then back it off a tiny amount, then plane".
This was fairly easy to communicate.
I started rolling the tip of an edge over i don't know how long ago - 5 years ago? It wasn't very interesting to anyone, but it stopped failure without having to make a blunt fat bevel like japanese chisels are often set when they're too hard (35 degrees or whatever). I didn't communicate it that well, but rolled it into discussion about sharpening being faster with slow stones because you can focus what you're doing where it needs to be done and not get caught doing useless work with stones because "they work fast".
I never measured the roll, you do what feels right, but if someone asks for a spec that works, it's pretty easy to provide. A 34 degree microbevel will just about stop failure for most people who are malleting a chisel. I don't like the way it feels. A 30 degree microbevel will not unless the work is only softwood. I didn't know those particular angles that I can recall until measuring to write an article, but they were pretty easy to find.
I have the luxury of having chisels 200 years old through chisels made recently in japan to a high spec - confirming that the range of angles that work well doesn't change much unless the chisels are outright junk. The range is about 2 degrees between OK chisels and the best chisels.
My point here is that I cannot tell anyone how to master something without them committing to using it and seeing what feels right, but I can get a good idea of what works and then measure them later (to avoid using a spec and then never varying because "the spec is right").
If I refuse to measure things like that and provide something that works, and follow up if it doesn't, then nobody ever starts in the first place. IT's not uncommon to come across people who say "that works for you, but won't work for me, or you say that works for you, but I doubt that's what you're doing", but you can write those people off.
I knew the double iron worked in 2010 or so because I'd set it far to close - it may have been before then. I compared a 70 degree effective back beveled stanley plane to a cap iron and both were about the same in resistance, but didn't know enough to continue to experiment because I wasn't far off. I just knew that the first try - no tearout and really hard to push. The thing that swayed me with the cap iron was how hard it was to dimension wood with single iron planes and the economic argument about why cap irons were included with planes (in a time when people didn't waste money).
the first person I communicated setting the cap iron to (chris griggs) had success with it. I didn't have to tell him how he would match someone working in a shop 250 years ago or it would be wasted effort, I just had to tell him something he could apply, which he did.
At this point, I can tell people multiple ways to eliminate edge failure, but I can't tell them a magic answer where they can use a 22 degree crisp apex as a magic trick with a certain steel at a certain hardness - it doesn't exist.
it isn't useful to tell someone that they will only be able to do something if they experiment themselves and are determined to master it.
I majored in math. I couldn't do paint by math - I don't have the memory for it without the why, so I eventually stopped paying attention in class memorizing application of basic calculus and went home and worked through the theorems until I understood their proofs and then it stuck. I sort of envy people who can take a description of something from someone else and just go repeat it because their minds will remember it and allow them to do it in order. Never worked for me, and I didn't have a professor clue me in on that - I struggled until I determined a way that I could learn and then didn't pay much attention in a math lecture ever again other than to make a list of the things I needed to learn.
That's unusual - most of the kids in the class had no trouble taking what they were taught and then just using it. The world is full of people looking to do something well enough and not look deeper, and there's nothing wrong with describing something simple that works for them.
