Sharpening, Steel or both.

[Jacob]

jacob, you don't know what you're talking about. You care about what makes sense to you, not results.
......

No it's results I'm after.
Good to see you have discovered stropping, albeit with a buffing wheel.
Ancient technique; usually by hand on leather, or with added compo, or Autosol on a plywood disc on a lathe etc. etc.
Yes it does make a surprising difference. Not least because the polishing effect will reduce friction between the blade and the shavings etc.

 

[D_W]

Yes it does make a surprising difference. Not least because the polishing effect will reduce friction between the blade and the shavings etc.

That's funny.

 

[D_W]

Polishing the cap iron, maybe. You'd have to strop an iron about 50 to 100 times to duplicate what the buffer does in about three shavings. I've shaved with a straight razor for about a dozen years now, but go ahead and try to tell me about strops.

 

[D_W]

Im going to have to read the unicorn link tomorrow, im a bit bushed for one day! I found it amazing just how much small things affected an edge. I touched up a razor on the lapping film, then ran it over a balsa strop with diamond paste, but i must have done something wrong because it was sharper straight off the lapping film ( arm hair test )

strange things happen with razors once you get past the point of the initial bevel. I have two microscope that I can use to look at razors, one was $425 and one as $13, I think. The latter is old so it's not comparable to what's out there now -but there must be something in between that's about as cheap as the latter that will help a ton.

What you find is that you'll either:
1) figure out what's not being done with the balsa strop quite right
2) what's wrong with the balsa strop itself

Shaving is interesting once you get into it - you establish an edge on a razor and then maintain it with a linen and shell strop (if you can find shell - old and unused is better than new and extremely expensive), probably for 200 shaves or so before needing to rehone for a couple of minutes.

But while you're cutting your teeth, it's tempting to get into super fine lapping films and such and feel like that's going to be a regular process.

Nonetheless, a very inexpensive scope is useful there to make sure you're not wasting time on things that don't work, and to separate the things that say they're fine from the things that are very fine. It's nice to get to the linen and strop, though, as razor care and shaving can be 3 minutes a day total if you want, with honing happening once or twice a year and a very ideal edge that cuts hair easily but doesn't cut skin at the back of the pore (razorburn) that's propped up by blade pushing the hair.

 

[JohnPW]

Is there any differences in steels and bevel angles for tools that are pushed (plane irons and chisels pushed by hand) and tools that are struck with a mallet (chisels for mortising)?

I meant to ask this upthread but I didn't phrase the question clearly.

 

[Jacob]

Is there any differences in steels and bevel angles for tools that are pushed (plane irons and chisels pushed by hand) and tools that are struck with a mallet (chisels for mortising)?

I meant to ask this upthread but I didn't phrase the question clearly.

Basically 30º does for all ordinary chisels and planes but you may hear differently from the enthusiasts!

 

[D_W]

Is there any differences in steels and bevel angles for tools that are pushed (plane irons and chisels pushed by hand) and tools that are struck with a mallet (chisels for mortising)?

I meant to ask this upthread but I didn't phrase the question clearly.

mortising chisel, higher final angle. paring chisels, you can push low, but they tend to crumble if you do. I think that a malleted chisel has an easier job than the corners of a paring chisel, but eliminating edge failure can be done for all. Pleasant softwoods don't require as much edge manipulation.

Of course, if you don't mind lines all over your work or sharpening chisels 5 times as often as needed, you can use a single method and single angle for everything. Eventually, you'd get used to dull edges and not notice how well the tool isn't working.

Bevel angles on steel is a factor of three things:
* hardness
* what and how you're working
* alloy

Anything where the alloy is bad enough for woodworking that it would come in shouldn't be used for woodworking, but that doesn't mean you'll never come across exotic tools with really high carbide large grains (e.g., you can find razors made out of S30V and such things -they're *terrible* and can cost 10 times as much as something made with simple silver steel rod die forged in a pair of dies and ground).

The effect of hardness is pretty minimal unless something is way too hard or way too soft (chippy or folds easily).

The angle where edge failure stops at the tip of plane irons and where it stops on chisels is fairly similar (32-34). Not "usability" under any circumstance, but eliminating failure due to anything other than wear so that you a good surface and least effort through wood. The latter is something every hand tool only woodworker I know gets into (brian holcombe was immensely interested in it when he was doing hand tool only, and a carver/woodworker here in the states working in a power-free shop is fanatical about edge condition because finding the elimination of edge failure is just a basic concept in carving and hand tool work that greatly reduces effort).

(other than prying mortise chisels to break chips, only the very tip of a bevel needs to be addressed at the angle mentioned above (32-34) to eliminate failure. If a chisel still chips/folds at 34 degree microbevel over a shallower secondary bevel, then it's too soft or too hard).

 

[D_W]

Rubber hits the road on a pair of parers - I need to send these out sharp with a shallow primary/secondary so they wow the person getting them, and so that the edge on the chisels lasts a long time. That avoids complaining about "i woud've sharpened them a different way"

I had to get a metal hammer out to finish driving the handle onto the tang of the larger chisel and it split two separate large pieces of 8/4 scrap despite being hammered perpendicular to the grain direction.

Not a single chip in the edge.

 

[baldkev]

strange things happen with razors once you get past the point of the initial bevel. I have two microscope that I can use to look at razors, one was $425 and one as $13, I think. The latter is old so it's not comparable to what's out there now -but there must be something in between that's about as cheap as the latter that will help a ton.

I got a small jewellers magnifying glass which isnt anything like good enough, but it gives an indication of how you are getting on when the tip / in my case secondary bevel of the blade reflects light ( i.e you can see if you are polishing out the scratches )

Ive got a cheap leather strop which j started on and thats actually where i get the best results. I had read that balsa strops are very good, especially for pastes, so i made a couple to try it out. I did lap them, however your comment about what i might have done wrong or if there is an issue with the strop itself made me stop and think.

One possible issue is the secondary bevel, in that by the time i tried the balsa and paste, i had *probably* taken the tape off the spine, as i tried the balsa the following evening.

Prior to the pandemic screwing up finances i was going to order a Tony miller pure vanilla, which i shall do soon....

 

[D_W]

I've done secondary bevels or tape every once in a while (rarely, but usually in the case of a razor that's having edge holding issues and would be helped by tape).

The longer term edge life is threatened when more than a layer or so of tape is added (if you start creeping the total bevel to 20 degrees or so, it doesn't take much dullness before it's not thin enough to get through hair easily. Sharpness at the tip is one thing, but thickness of the bevel behind it is another - the fatter you push the thickness, the more dependent the razor will be on the very tip of the bevel.

The best razors are the ones that really tolerate that low angle without modification, which turns out to be the most plain steel that kind of hangs in there at low angles in the low 60s hardness range. Overhard razors lack toughness and don't like a strop, and underhard razors deflect. It's a lot like tools, except the margin of error goes from sort of a range to almost nothing. Any quality issues at all or poor alloy choices with razors and it doesn't work.

But, definitely something in the 75x optical range or so will lower the amount of work that you do and not increase it. Now that I have the metallurgical scope, when I go to dump something on ebay, lean on it to not do any more than I have to as the light work gets boring.

The stropping work can really take a well done bevel over the top (the kind of submicron oxides, etc), but if the edge isn't quite there to start, it just won't get it there without gobs and gobs of passes. Not a fan. Too lazy -I just want the result and don't want to pride myself on being able to move a razor across a slow medium 300 times.

 

[Jameshow]

I finish my edges with 2000 grit paper should I think about getting a polishing wheel / strop?

I work mainly pine btw.

Cheers James

 

[baldkev]

The unicorn method looks good, will give it a try. I need to do my chisels soon, its been a while!

 

[D_W]

I finish my edges with 2000 grit paper should I think about getting a polishing wheel / strop?

I work mainly pine btw.

Cheers James

Something *very* inexpensive like a fine white bar with a drop of oil on softwood used as a "strop hone" (just pull and round the bevel a tiny bit on purpose) will add worlds of sharpness and edge durability.

Once you learn to nail it, if you do an A/B comparison against an iron sharpened on a 2k stone, you'll notice how much less effort there is with a plane and how much more easily a plane stays in the cut.

With a chisel, I guess it's up to you. I like good geometry and very high polish to negate dealing with a wire edge.

As far as cost for this step up, we're talking like 5 pounds -a 2k stone is 95% of the way there in work, you just want to polish the tip of the iron or chisel to get over the top.

Kid you not that a $1 buff bar that I got on clearance at sears would last several years. softwood or medium hardwood will provide just a little cushion and make a stronger apex than an aggressive small micron stone (also makes it easier to finish the job).

 

[D_W]

Here's two pictures comparing edges:
this one I had named "$3" edge. $1 of psa roll to grind, $1 flea market extra fine india, $1 white buff bar mentioned above:

Notice the uniformity at the very edge tip. If the non-grind part of the cycle here took more than a minute and a half to really nail on a dull plane iron, I'd be really surprised.

Note that the odd scratch here or there is either dirt on the wood or the large particles in the grade of the bar. Note how uniform the edge is (particles like that are common in a buff bar - the grade can be looser than lapidary grit because they're used in a cotton or sisal buff and those big particles can't dig deep).

Here's a shapton cream (12000), which I think marks the edge more like a 2-3 micron stone (likely the 1 micron grade is an average and there are big particles). It cuts as fast as any 8k stone I've used, so there's some secret there that's not that secret.

For the comments above re: razors - when you sharpen a razor with a shapton, it always feels tricky to get it right. The "gurus" on the shaving forum will say that the stone is very aggressive, but they're off the mark - it's just coarse.

But it's fast and practical because of it (and if you buy it from japan, not expensive).

I don't have a bunch of medium 2k type stones to offer pictures of - I don't finish with them, but you'd probably get an edge similar to this fairly new queer creek norton.

(the edge from a synthetic stone will be more uniform looking with narrower deeper scratches, but its' the best I've got to compare).

No, looking at that -I'm wrong, it would be a lot more coarse than that. QC is a sandstone type, so it semi burnishes the steel and also the bigger particles deflect it. That's why they're a budget stone compared to oilstones of novaculite.

 

[D_W]

(the uniformity shown at the top will gain at least 50% more edge life in smoothing if you can avoid stuff that damages irons. The buff bar on medium woods takes the place of a leather strop in about the same amount of time and you can ignore stropping after it - palm strop if it makes you happy.

Here's an illustration of why I say wood and you can't just swap around - here's dursol polish on cast iron:

Note that cast is hard, as is corian, as are very fine oilstones - if you increase pressure to try to finish an edge faster, you'll get little chips like the ones here. It doesn't matter that much, but if they get twice as big as that, they'll spoil a surface.

Same iron, same dursol, but on yellow pine (subjectively just as fast, and easier with a much better feel - the odd piece of dirt floating around doesn't just batter an edge).

 

[D_W]

none of these super fine edges, by the way, are prissy or fussy. They are the product of getting the work done before them properly - at a lower angle, so that you can get all of that fine work done on both sides of a bevel absolutely completely in about 20 seconds.

inexpensive extra fine india before this for me (norton has a part number for such a stone, but I haven't found it other than flea market stones in other brands, and japan - 2k-ish grit india stones were popular in japan for some reason. They won't finish an edge, but they will clean up the work after a grind with a second bevel and let you treat the tip. Very lazy, extremely durable and every bit as effective as some eons-long routine to treat an entire full flat bevel).

You need separation of angles to get the edge done like this, else you'll just have big stray scratches coming to the tip and what's the point, then.

 

[pe2dave]

Diamond plates, finished with a leather strop. Works for me.
Kitchen knives with the steel.

 

[Jacob]

mortising chisel, higher final angle. paring chisels, you can push low, but they tend to crumble if you do. I think that a malleted chisel has an easier job than the corners of a paring chisel, but eliminating edge failure can be done for all. Pleasant softwoods don't require as much edge manipulation.

Of course, if you don't mind lines all over your work or sharpening chisels 5 times as often as needed, you can use a single method and single angle for everything. Eventually, you'd get used to dull edges and not notice how well the tool isn't working.

Bevel angles on steel is a factor of three things:
* hardness
* what and how you're working
* alloy

Anything where the alloy is bad enough for woodworking that it would come in shouldn't be used for woodworking, but that doesn't mean you'll never come across exotic tools with really high carbide large grains (e.g., you can find razors made out of S30V and such things -they're *terrible* and can cost 10 times as much as something made with simple silver steel rod die forged in a pair of dies and ground).

The effect of hardness is pretty minimal unless something is way too hard or way too soft (chippy or folds easily).

The angle where edge failure stops at the tip of plane irons and where it stops on chisels is fairly similar (32-34). Not "usability" under any circumstance, but eliminating failure due to anything other than wear so that you a good surface and least effort through wood. The latter is something every hand tool only woodworker I know gets into (brian holcombe was immensely interested in it when he was doing hand tool only, and a carver/woodworker here in the states working in a power-free shop is fanatical about edge condition because finding the elimination of edge failure is just a basic concept in carving and hand tool work that greatly reduces effort).

(other than prying mortise chisels to break chips, only the very tip of a bevel needs to be addressed at the angle mentioned above (32-34) to eliminate failure. If a chisel still chips/folds at 34 degree microbevel over a shallower secondary bevel, then it's too soft or too hard).

The effect of hardness is pretty minimal unless something is way too hard or way too soft" is what as known as a tautology, or self evident truth.
So after all those pages and consideration of all possible variables, the answer for everything is 33º plus or minus 1º?
I'm not convinced - I'll stick with 30º plus or minus 1º
There's an intelligible answer to the ebony question here Woodworking with Ebony - FineWoodworking
which is very conventional and familiar. I don't believe in magic numbers.

 

[D_W]

Jacob, I don't really care what you're convinced about. you're convinced that you don't want anything to change, and that's fine. I don't really care what you believe in, either. I only care what is.

Hardness makes a fairly significant difference in chisels. 59 and 62 in the same steel will feel like different chisels. But I doubt you have the exposure to know. I tested irons last year and a chinese high speed steel iron honed really crisply. I was very surprised by just how crisp it was (you'd think it would hold a strong wire edge). A chemist here demanded to take all of the irons and have them XRFed and hardness tested if either was unknown, so I mailed them to him. The iron was over 65 hardness. It made it feel like an icy carbon steel.

I boiled down a final angle for planing and regular chiseling based on observation. 33 or so is what I would say is where to start to eliminate failure. 30 degrees will probably eliminate failure if you only work pine, but in any hardwoods, even simple maple and cherry, failure is there.

What I found mortising plane bodies in ebony and rosewood is that serious edge failure (e..g, if you found 32 degrees worked for your set of chisels, and then determined that they were junk and it's time to buy something more expensive to work the "hard woods") can usually be eliminated with another two degrees or so.

Reality only matters if you're shooting for results in reality.

When you can game reality and results to less effort, then that's beneficial.

I use a buffer on chisels and round over the tip abruptly. Some people don't want to do that. If they want a sweet working chisel, they're far better to grind at 25 and put a tiny stripe on at 34 than they are to do everything at 30. They'll hone a fifth as much in hardwoods and the chisel will get through the wood faster. That's reality.

 

[pe2dave]

Jacob, I don't really care what you're convinced about. you're convinced that you don't want anything to change, and that's fine. I don't really care what you believe in, either. I only care what is.

seems like a summary. I do wonder why you bother with the forum with such fixed ideas.