The shavings may go the 12-15″ due to physical ability to put downward pressure on the plane with a thicker shaving in oak, or wood that is either not totally flat on one or both sides or is not supported on a flat enough surface.
This is all normal stuff around hand tools and the work surfaces you use when working. A flattened workbench is a big help depending on how you hold your work and how big your boards are. You’re on your way and I can suggest that its just a matter of continuously and patiently problem-solving for the fun of the whole process.
I watch people like Paul Sellers, try to pick up on the nuances they share, and put it all to the test with real live action. Here some thoughts on stock prep.
I find Paul’s method of planing the faces of boards while clamped in the vice quite interesting. He is able to take shavings down the length of a board while its only clamped in the middle, and he does it all the time. The clamped board acts as a spring against which he is working while he planes. I find this wild and crazy in the best senses, and probably genius if you can work accurately this way! Paul works very efficiently in hand tools.
By contrast, others will use a workbench that is flat, supports the board as it is clamped / stopped in some form, and rely on the support underneath the board as they true the board. In this method, I will slide shims such as index 3×5 cards or thicker if needed, to support a board that is not true, as I begin to true one face. This shimming becomes rather a necessity while flattening thinner boards around 1″ thick. A 3″ thick beam won’t need those shims as much because it won’t really deflect under planing. Then, with one face flat or nearly flat, I may flip the board over and work to true the other side more easily, now that the opposite side is resting more consistently on the flat workbench. Then I may decide which side will be the “Face” “Reference” side from which I’ll thickness the board. The second side may be the likely side that I stick with for fully truing since its now fairly well-supported by the roughly trued opposite face. And prior to this, the edges need to be somewhere near a right angle to the reference face. I do work some boards in the quick release vice like Paul Sellers does. But I now also have a bench that has a working wagon / tail vice and bench dog holes all down its length. I have found it helpful for flattening very large, long, heavy wide boards. For what its worth.
But now you can see how Paul Sellers flattening his boards in the vice jaws bypasses all this shimming and perfectly flat workbenches handily… He has been doing it for so many years that he, the tool, the wood and the bench all hum along perfectly. I suppose its a question of what you ultimately find reduces variables in the way of success. Paul may view the requirements of a flat bench, tail or wagon vises, bench dogs, and shimming of stock as unwanted variables compared to his effortless style at the English workbench and its quick-release vice. Another may prefer the approach where they work up through a big Roubo bench and super-controlled sharpening with honing guides to get results. Less freehand, more guides and reference surfaces I guess. Far from me to say one way is wrong or right. They are just different. Another example: Paul uses a mortising guide clamped against his work as a reference for the chisel. Somewhere along the way, he decided that having such a guide was a useful aid to making better mortises. In this case, the decision was in favor of a guide of some type to keep things straight rather than relying on freehand and sighting of the tool / work. So even with one person, they may go one direction or another based on what works best for them.
Relaxation of the body is key, I think. Tight grip and tense muscles may make it harder to process good feedback and balance while working with hand tools. Yes, pressure and force are sometimes needed, but they are not the same as undesirable muscle tension. For example, if you want to hold out your fist and keep someone from moving it, you will naturally tense up all opposing muscles in your arm, and probably your shoulder and core muscles. We can do this with tools too, and not realize it fully, tensing up our muscles to get more control, we think. But if we sharpen our minds and focus on being sensitive to the tool and the wood, we can build confidence in the forces we apply without having to rely on “opposing muscle tensions.” I tend to naturally over-tension my body at times without realizing it. I give things the death grip too easily whether its a pencil or a chisel handle. But this needs to be “thought” and practiced against. I drink regular coffee but I’m trying to cut back and drink more decaf. Too much caffeine seems to put my mind toward tighter grip / more tension if anything. But I’ve been hooked on coffee for way too long. Such is life.
I should probably give your thread here a break for your and others’ sake. Good luck and best wishes as you continue John! Too much writing here from me in the light of what we want is simple clarity and a peaceful way with woodworking!