I agree that may be what happened. I've don't often get a piece of red oak that tears out a lot, but this ONE piece has got a couple square inches area that's a bear to plane cleanly. I got it perfectly smooth, then grabbed low angle block plane and in one pass left it looking ragged again. That area, when smooth, looks to my eye like the rest of the surface. Is there no way to tell what wood will tear out, by some visible feature, in the grain?
Dave
I never thought of it that way. I drew a couple pictures real quick, as I read your statement. I agree. seems counter-intuitive, doesn't it??
Dave
I don't have a weatlh of experience, but I know when the grain looks like little eddys in a pool of water its going to be a bear. With a very sharp blade, you are able to make other adjustments that help tear out. First, set the cut depth to make very thin shavings. If the plane has a mouth adjustment, set it very tight. Lastly, planing diagonally or in kind of a swirling motion may help with these tough areas. Alternatively, a cabinet scraper may save the day.
Bob
I am always willing to admit I am wrong. You are right, I was wrong. Thank you for posting the pictures, that helps. I've learned something Back bevel does indeed make the edge more durable. I had it confused with micro bevel.
Bob
You are correct. I confused back bevel with micro bevel. I need to take my own advise often given out. When in doubt draw pictures or make a model to really understand.
Thanks, Bob
Ah, thanks for that insight. I'm going to go do a back bevel on one of my planes. I need to exercise my new Lee Valley honing jig. :-)
Bob
I do set the plane for very light cuts and the mouth so narrow you have to hold it just right to see daylight through the tiny slit. :) I have a LV scraper plane which I've learned to adjust pretty well now, so that I can get a wonderfully smooth surface. Thanks for the additional suggestion (swirling), Bob.
Dave
.....about why back bevels work (on bevel down planes)....
tearout happens in stringy woods when the wood fiber is strong enough to pull up ahead of the cutting edge. think of sliding a putty knife under the lifted end if a splinter. it levers the splinter out of the board, ahead of the edge of the knife. now imagine lifting the handle of the putty knife up until the splinter breaks. you've increased the angle beyond the bending ability of the splinter.
this is what the back bevel does. it forces the shaving to curl to the point that the long fibers can no longer apply upward action ahead of the edge. it also increases the total included grind angle (makes the edge thicker) which tends to make it stay sharp a bit longer between sharpenings.
That doesn't make sense to me--unless: The back bevel (we're still on bevel-up planes, right?) is going to change the relief angle. Are the long fibers you're talking about the ones under the blade, after the edge has passed? If so, it makes sense; back bevel in the bevel-up situation will lower the relief angle. The back-bevel could put a teensy bit of pressure on the fibers just below the fibers which are now riding up the blade. These still-in-the-wood fibers can't join the growing 'splinter' ahead of the blade, because we're pinching them back against the wood. I think...
Whatever, I still think OP just had a sharper blade.
the quoted was about bevel down planes. sorry about the confusion...
nah if the heel of that bevel is deeper than the edge the plane will climb right out of the cut.
probably.
Pictures & text here (scroll down):
djb
Two thoughts.
First, can you really tell which is the bevel and which the flat surface when you're talking the engaged (
That link has an excellent explanation of back bevels for both bevel up and down blades.
Dave
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