Y'all are too much....ROTFLMAO
MsBubba is Scottish, we've been together going on 15-16 years and she still doesn't understand a thing I say.
ken
Y'all are too much....ROTFLMAO
MsBubba is Scottish, we've been together going on 15-16 years and she still doesn't understand a thing I say.
ken
I certainly did not think this was about hollow grinding the backs of chisels. Why in the world would anyone hollow back their chisels? Hollow grinding the bevel, as Derek and others have noted, makes perfect sense ...
Yes, by the way, I know the Japanese do this as a design practice. I'm not talking about those.
If you know it, then please don't bother responding with "Why in the world would anyone hollow back their chisels?"
There are plenty of people that grind a hollow on the flats of their Western planes and chisel blades... even the soles of steel bodied planes. It works. Don't knock it if you haven't tried it. Makes sharpening those LN A2 blades a lot easier.
Last edited by Stanley Covington; 02-20-2018 at 8:41 AM.
I guess I'e not seen that type of thing even discussed here in all the time I've been reading. Does Warren do that? Who really does? If anyone does this routinely it would be enlightening. Otherwise its just more bs as far as I'm concerned. Of course, thats most of what seems to be discussed here these days.
[BS alert:] I hollow grind sometimes for simple convenience when re-establishing a bevel. It's just fast. It has the nice benefit of giving a nice crutch (2 point reference) for free-hand sharpening, but even the necessity for this goes away with time and practice. I am unsure if it's accepted practice, but I tend to hollow grind mortise chisels the most. I definitely appreciate the 2-point reference for quick and frequent freehand honing. I find it tricky to use jigs on those thick, narrow blades.
Prashun
You may want to read a resent thread Ray Iles Mortise Chisel post #9-12 about hollow grinding mortise chisels.
I read that, to my chagrin. But I have not noticed that it is a problem. My chisels seem to work fine.
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I suspect I might get in trouble for doing this to a western blade (and on my first post here too good going me) but I ground out the back of an old vintage blade last year; mostly for ease of sharpening and just plain experimenting. I had already ground out a slight hump a few years ago and left about an inch of untouched flat steel from edge upwards and 3/4” from the sides in. Unsightly and still a massive amount of steel to flatten. I didn’t touch it for years then one night I rigged up a jig (tape and an failed woodie prototype) on my bench grinder (CBN wheels and no I didn’t overheat the blade even a smidge) and went at it. I tried ura-dashi and it actually worked rather well, didn’t take much to flatten. Finished honing it on a Jnat, haven’t got around to making a body for it. I’ve convinced myself to think of the look as a multiple hollow Japanese chisel style but evidently it’s a far cry. The ridges in between grinds also do not touch the stone whereas multiple hollow chisels do (I think). While it may look like a big multiple hollow chisel the grind is entirely geared for a plane blade, the ridges won’t touch the stone in most of my lifetime. Along side the real deal the looks don’t hold up but function wise it’s improved. I would do the same to a lot of other western chisels and irons if warranted and on tools I make, laminated or not.
As for hollow grinding bevels if you have a 1/4” thick blade you’re not sharpening a face that’s 1/4” widthwise unless you’re sharpening a Bevel at 90 degrees. Even then I’d hollow grind that. With a 25 degree bevel on a 1/4” blade (shooting plane) your looking at a surface area that’s more like 7/16” in width. At this point two 1/16th strips sound pretty nice — it actually takes a while with a nicely ground blade to get to that point (assuming you pop out the blade enough for touch ups and don’t let the edge get too deteriorated. When sharpening you try to abrade the bevel so it moves past the wear and then repolish it. If you tried to take a 1/64” in thickness off your workbench that’s going to be slower then taking off a 1/64” off two 1” wide strips of wood (same length, species etc) If you have less metal on the bevel your’re going to get past the wear faster. It’ll also polish up a lot quicker. Imagine having to hone a flat ground straight razor. That would take forever from your first stone to the last. Below is a picture of my shooting plane iron (taken for social media so filtered to look hipstery). On the bottom pic you can see the bevel right after a grinding. On the top pic hopefully you can see two tiny strips that are polished. They’re hazy because I finished up on a Jnat and a bit bigger than what one could get off a fresh grind; I was experimenting with a few different stones. So speed is one thing but self jigging, accuracy, etc are all benefits. A nice CBN wheel goes a ways for speed and peace of mind too. At this point I’m rambling but hopefully sounded coherent. Let me know if pictures won’t enlarge, I’m still figuring out how to post.
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Vincent Tai
Howdy Vincent and welcome to the Creek.
You touched lightly on my biggest problem with a flat bevel. My #62 has a thick blade. When my water stones are relatively flat the bevel tends to get stuck on the stone due to the water's surface tension. Usually this can be dealt with by sharpening side to side.
jtk
"A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
- Sir Winston Churchill (1874-1965)
The cutting edge is only one part of a chisel. Its job is to sever fibers. The chisel also acts as a wedge, pushing material aside as it goes in. A hollow ground bevel makes a poor wedge and it makes the edge vulnerable because it fails to open up a good pocket for easy exit of the tool. The edge penetrates deeply and gets stuck deep in the cut. Then it is vulnerable to chipping and bending.
Some think it wise to use an exotic steel to resist edge deformation. Then the steel sharpens poorly so they hollow grind. A vicious cycle.
Thanks for the welcome Jim!
I had a really rough time with sticky flat bevels. Still do on my Japanese chisels, and some of them have microbevels out of frustration. Side sharpening really works for me too, I guess all that’s left for me is to sharpen some more and let time do it’s thing.
Vincent
More heresy but something I have tried recently with no disastrous results. Soak the stone than remove the visible surface water and go at it with the blade as per normal. The sky won't fall in and the sun will still rise in the east and you will be surprised at the result I know I was.
Chris
Everything I like is either illegal, immoral or fattening
My brain is beginning to hurt a little, but this is a fascinating discussion.
I do have a question. If you have a hollow ground bevel and are chopping, or are paring with the bevel up, wouldn't the flat side act as the lever and keep the blade from digging in?