A back to basics question here. Been having trouble squaring stock and meeting the finish dimensions with hand plane. Source of trouble is tear out. Seems like by the time I finally discern the directions to plane, I’ve gone beyond finish dimension just to eliminate tear out. Second problem is that I love figured wood, but I’m talking here about only lightly figured wood, as in near a knot, but not actually having the knot in the board.
Anyway, near as I can tell I got two choices:choose only straight grain or start with thicker stock so that I have time to figure out grain directions before I go too far. Is that right? Do you have to start with heavier stock, say 7/8 instead of 3/4 when you deal with figure? OTOH there’s lot of muscle work removing that 1/8″ from a board.
Or do you make life easier for yourself and avoid figure?
Dave of Fla.
Replies
Dave,
I try to avoid all the muscle exercise that I can--even though I use hand tools exclusively. I don't avoid figured woods; but I keep in mind that some woods refuse to be planed. I can usually tell pretty well after a couple passes if the wood is going to respond well to the plane. If not I stop planing before I reach my finished dimension and switch to my scraping plane (nothing fancy, just an old garage-sale Stanley #80). About the only other thing I know of to try is a high angle smoother, a York pitch or more (I don't have one so I'm just repeating what I've been told).
I love my planes, and I love using them. But they can't do everything.
Alan
A plane can, if sharp and properly set surface nearly any wood, without tearout. You don’t need to avoid figured wood, since that is one of the best parts of woodworking, showing off highly figured lumber. Your first couple of passes should be made with the plane set for a very fine shaving, even if you are hogging off a lot of material. This will give you an indication of the trouble spots , before they tearout. Having said that, I rarely need to do this, since looking at the board will usually tell me where there is going to be trouble, and after time you will be able to do the same. One of the best things you can do is to hone a very slight (5 degrees) back bevel on your iron, after first grinding the primary bevel 5 degrees lower than normal. This bevel should be so small that you can barely see it. This has the effect of raising the bed angle of your plane, which goes a long ways towards eliminating or minimizing tearout. You should also plane across the grain to remove the bulk of your material, since planing this way prevents tearout, but leaves a poor surface (and it goes faster than going with the grain). If after trying these ideas and you still have trouble, plane across the grain or diagonal to it, to achieve a flat and properly dimensioned piece, and switch to the cabinet scraper to finish up. The scraper won’t leave a surface comparable to a plane, but it will do very good. The scraper won’t work on softwoods, or at least it won’t work very well.The best investment you can make is to buy a Lie-Nielsen number 4 ½ smooth plane with the high angle frog.
rob,
What is a back bevel? Does it go on the flat side or the bevel side of the hock. I have heard the word bezel...is that the same a bevel...help! thanks
I'm sorry that I did not make it clear what I was talking about. The back bevel goes on the side that the cap iron goes on, inother words, thes side opposite of the standard bevel. I know that this breaks a firm rule, about keeping the back flat, but it has the effect of raising the bed angle of a bench plane. This won't do a thing for planes that have the bevel up, like block planes. This has one other benefit, if your iron back is not flat or is scratched, you don't have to go through all that lapping, since only the last tiny fraction of an inch needs to be worked on the stone.
the back bevel will work. But dont overlook tuning up your plane and blade. If you think its sharp, make a few more passes. Sharp is a good thing.... Tuning might be readjusting your chip breaker and closing your throat opening. Round the edges of your plane so the sharp 90 degree corners dont tear or put hard edges.
But nothing beats experience, which im still working on.
Could someone give me a rough drawing or pix of the rounding of the corners? How much, etc. I am building a piece where I do not want to use sandpaper, only a plane. But the hard edges are an issue. Thx.
I have never been a fan of rounding the corners of a plane iron. Instead I hone my blades to a slight ( very slight) curve. What I aim for is a cutting edge that is about ..002"-003" higher in the center than it is at the edges. Since a well-tuned plane can take a .001" plus or minus shaving, you end up with a smooth surface across the entire width of the cut. When you round the corners, it leaves a tell tale mark since the transition is too abrupt. I do round the corners on my jointer plane, so I know from experience which method produces the best results. It may sound difficult to produce a cutting edge that is crowned a mere .002"- .003", but all you need to do is establish a very flat edge on your stone. Then while doing the final honing just apply more pressure at the sides of the iron. I work my bevel straight from the grinder, buy pushing it over the stone parallel to the cutting edge of the iron, as this will establish a very flat (straight) cutting edge. Then I hone them on sandpaper glued to a flat piece of glass, applying more pressure to the outside edges. Going in a figure 8 pattern. Holding the iron up to a straight edge will give you an idea of how you are doing. What you want to see is just a crack of light at each edge, tapering back to center.
I see, so not only do I have to master the use of the plane, but become a master plane engineer! I'm an amateur who just learned how to tune my 14" jack plane that I use for just about everything. While I can sharpen my blade near perfect, I d on't have a grinding set up (another 100 bucks)
Frankly, I don't see any way around perfecting my use of planes as I'm addicted to figure. Too much arthritis in the fingers to use a scraper for long. Straight grains put me to sleep. Do you consider it mandatory that one master grinding blades as well? I have a 9" plane, but it has the same frog angle.
Dave of Fla.
I’m sorry if at any point I gave the impression that you must become an engineer, nothing could be further from the truth. I grind my irons on a hand-cranked grinder that I purchased as a kid ($10.00 at flea markets today). Even as a kid (12-13) I could sharpen blades that could you could shave with (I didn’t need to shave then) so if some punk kid can sharpen a planeon a hand grinder anyone can. The idea behind the back bevel and the higher bed angle is very simple. The higher cutting angle makes more of a scraping cut. You can see this difference quite clearly with a LOW angle block plane compared to a standard bench plane. The block plane is no matter how tight the throat or how sharp is far more prone to tearout than a bench plane. Yes, there are other factors such as solid bedding and mass, but the point still holds true, a higher bed/cutting angle yields a better cut. This is why many molding planes and smooth planes had their bed angles at 50 or more degrees. Once you learn to read the grain, and get comfortable with planing around trouble spots you should end up needing only minor scraping and most of the time none at all. I planed a really "woolly" piece of mahogany 18"x 25" yesterday, in which the grain was constantly changing directions, and I ended up needing to use the hand scraper for about 15 seconds. Again this is very simple stuff, which is not something I dreamed up, the ideas are at least 200 or more years old.
'Preciate your reply. I've just spent so much time recently perfecting machines and tools that the idea of do it some more doesn't sit well at the moment. I'll get over it.
I can read the grain, what I have a hard time is when it changes direction three times along the length as well as across the face!! That's where I get in trouble. I can handle two directions where you work the board from both ends, but changing in the middle, arrggghh! First time working with cherry which is much more delicate than expected.
I understand the blade angle thing -- the block plane is lifting and cutting. If the blade is more nearly vertical, it then has a shearing action without the lifting. I don't understand the idea behind the secondary bevel. With machine tools, that's called a relief grind, and as far as I know all it does is prevent heat build up by reducing friction, though I suppose that could help reduce tear out a tad. But I also think it makes the blade edge much weaker and will dull faster, especially around knots.
Anyway, I've tried grinding without some kind of guide - what a mess I made of the blade! Is it possible to cobble up your own grinding guide fairly easily? I have a bunch of scrap aluminum shapes I could use.
Dave of Fla.
I have attached drawing (crude) of what I’m describing. I’ll be the first to admit, that this back bevel is not going to magically turn a standard Bailey type plane into professional grade smoother, but I have used it for some time, with excellent results in my 1970’s era Stanley planes. The back bevel, just has the effect of raising the bed/cutting angle. In other words a 45 degrees bed angle with a 5- degree back bevel gives you a cutting angle of 50 degrees. Since the same amount of metal is backing the cutting edge, it is not any more fragile than a standard grind, but I do believe as you noted, it may dull faster. That is one reason I switched to A-2 blades, but that’s whole other story. I can’t help you with the jig for a grinder, as I just pinch the iron between my thumb and forefinger of my left hand, and guide the blade over the wheel, letting my finger act as a guide against the tool rest, besides I hate jigs. I know what you mean about grain changing direction in mid stream. I use birch for card table hinges, and that stuff is terrible to plane. My homemade high angle smooth plane (55 degree) and my Lie-Nielson No. 41/2 make short work of it, in large part due to the bed angle.
Ah, well I just tried my little 9" Craftsman, don't know what it's technical name is. I just noted it's a higher quality than my Stanley and the frog is 5 degrees steeper! I moved the frog back a bit and gave it try -- much better, I'd say about 50% less tear right near a knot. I also noticed that I can control it a lot better: for reasons I can't fathom why I can stop it in mid stroke, whereas with a bench plane I found it impossible to take short strokes. That means that I can note grain changes and adapt easier. I'll try the bevel later, maybe that will yield even better results. Well, sir, that's one problem solved. Thanks.
I'm still amazed that you can free hand grind a blade! Presumably you're just eyeballing the angle too? Or do you have some kind of guide/
Dave of Fla
If I can jump in here I hope I might be able to clarify some basic terminology.
99.999% of all woodworking tools are based on the simple tool the wedge. In identifying the 3 angles involved in presenting/using a sharp blade, there is first the hook or rake angle -- that is, the angle between a line perpendicular to the wood surface and the face of the cutting surface. The actual angle within the blade/tooth that constitutes the actual wedge/blade/tooth is generally referred to as the sharpness angle; and finally the angle between the back of the blade/tooth and the wood is referred to as the clearance angle. Generally the sum of these three angles is 90 degrees.
By putting a bevel on the front side of the blade, Rob is effectively reducing the hook angle and increasing the sharpness angle.
He could further increase the sharpness angle if he were to reduce the clearance angle but one can only reduce the clearance angle so far because during cutting, there is a certain amount of compression of the wood and once the blade/tooth passes, a level of springback.
By increasing the sharpness angle and decreasing the hook angle, Rob is effectively increasing the thickness of the wedge. As such, it becomes more difficult to drive that wedge into the wood (increased sharpness angles require more power), even when there is downward sloping grain. Downward sloping grain, if a blade/tooth/wedge is driven into it will at some point break off or tear out as the forward movement of the cutting tool continues. Because the wood is cracking ahead of the blade, when it breaks off, it is often below the plane (as in planar) of the blade/tooth.
The term "sharpness" is very relative. It really has little to do with the actual sharpness angle, but, in my thinking, deals with the smoothness and integrity of the very tip of the wedge. A tool becomes dull when the wedge tip is rounded over or broken.
I am really impressed with Rob's approach to reducing tearout with hand planing. It is so perfect in concept and so simple in application, and I have never heard of it. On the very best days, you learn something new. Thank you!
Well, I’m glad that I was able to impress someone, since I rarely if ever do that. But, honesty forces me to say that it was not my idea, I don’t remember where I heard/read it, but it has been many years. Also, I have since heard other people advocate it.
When it comes to woodworking, it is almost impossible to say that you thought of some idea -- we are really just a conduit to transfer past knowledge to somebody else in the present and future. That you did not "invent" it does not in any way diminish its importance. You must do some awesome work!!
I imagine that you have been using this technique for a number of years; I'm certain it works and works exceedingly well. I have recommended doing the same thing on planer knives but I never thought about applying it to my hand planes when I am doing highly figured woods.
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