Problems bringing pieces to thickness

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    Eric Vogt

    Hello everyone,
    Im new to working with only handtools and have massive problems with planing my pieces of wood to thickness.
    I start with trueing one face and one edge. Then i size the width of the piece based on my reference edge.
    But when it comes to thicknessing based on the reference face i always end up with one site or corner on my marking line and get an bump in the middle and dont have enough material to remove the error. I cant figure out a way to prevent this, do you have any tipps? Thanks for your advises

    Sven-Olof Jansson

    Hej Eric,

    Scribing the face the face and the edges with a soft pencil is what helps me a lot. I picked it up from videos by Mr. T. Fidgen and D. Charlesworth. The edges only need to be scribed down to the gauge lines.

    It can be a bit tedious having to frequently re-scribe the face, but there’s instant feed-back on how the planing is progressing. The scribing of the edges is more to give a hint on how close I am to the gauge lines.

    Mr. P Sellers’ technique of clamping the ends of the board and then locking the clamp in the front vice, with as much as possible of the board resting on the bench top, might perhaps be of value, as it does away with any potential flexing that might occur when face planing with the work piece in the front vice.

    Sven-Olof Jansson
    London, UK; Boston, MA


    The only way i could ever make it work is to mark all four sides and plane at an angle to each line. Going lightly to stop at or before it a bit.
    Then when all edges are to the line go across or diagonally keeping the plane level.
    Mark the board with pencil lines every few inches and if you plane a line off on one of the slopes remark it.
    The hardest part for me is to bAck off the iron and sneak up on flat with the plane.
    Go slowly and watch the lines. They get shorter and shorter

    Colin Scowen

    If I understand the situation correctly, you are able to get the boards flat and true, and mark a thickness line around the edge (green), point 1. You are able to plane a bevel close to the thickness line, point 2. You are able to continue planing until you reach point 3, where you have reached your thickness line, but still have material in the center of the board. Place a spirit level, or other reference straight edge across the board, so you can see where the hump is greatest. Scribble some lines in that area, and then with short strokes, plane only in the middle. Once the lines are all gone, check again. As you move closer to flat, the hump will get smaller, and the amount that the level will rock and the amount of gap you can see between the board and the level will also get smaller. If it helps you, you can also mark the ‘nearly there’ areas with a different colour or thickness pencil, so that you will know if you are planing too long. This is shown on the top view. Once you are almost completely flat, then you can go back to full length passes.
    It is also worth considering how flat you really need to be. That depends on what you are going to use finally thicknessed piece for.

    Colin, Czech Rep.

    • This reply was modified 1 year, 3 months ago by Colin Scowen.
    • This reply was modified 1 year, 3 months ago by Colin Scowen.
    Sigurt Dinesen

    This may not be your issue, but I wanted to add that if, in following Collin’s advice, you encounter strange planing behaviour where the plane will skip over identified highspots, and take a shaving on low spots, the board might be twisted.
    Checking for twist, even on the opposite side of the face, is valuable, because a twisted board is deeply unintuitive to read.
    Several times, i’ve sighted a board, and checked with a straightedge, only to have the plane make the low spots lower, and the high spots highler.
    Most of those times, it was because twist made me misread where the high spots actually were.

    I’ve come to see winding sticks not as optional for stock preparation, like a straight edge is, but as completely essential.
    Unlike the square, the winding sticks don’t have to be perfect in my experience. They just need to get you get you close enough that the readings from your other tools make sense.

    Might not be your issue at all, but worth keeping in mind.

    If you keep running into trouble, stay patient with yourself. Maybe practise stock prep, not for a particular project, but just to practise stock prep.

    I’ve also found that using long planes have more of a tendency to ride over a big high spot than shorter planes.
    It’s easy to just skit the the sole over them, keeping the iron in the air. Using a shorter plane, or skewing the plane, helps this.

    Eric Vogt

    Thank you for all your advices and tipps, I will take my time in the shop on the weekend and try the things you guys mentioned and stay focused on the behavior of the plane. I think the trick with staying patient and often mark the wood with pencil lines could help me really a lot to see where things happen on the surface of the piece.
    I will be back with feedback once I taken my time in the shop.


    One thing to keep in mind is that not all situations require 2 perfectly flat and coplanar faces. A small variation in thickness may not be noticeable. For example, the underside of a bookshelf. Also, the exact thickness of a piece is not always critical; it’s probably not going to be noticeable if that same bookshelf is 3/4″, 23/32″, or even 11/16″, as you should mate the individual dados to the individual shelf pieces anyway.

    Also, using a smaller plane (#4 or #5) and focusing on the high spots alone while checking for twist is a good path, as noted by others here.


    So true. If your outside shoulders of a tenon are all the same depth the reveal will be the same. NO one sees the inside face.

    Sigurt Dinesen

    I think georgewall4 and deanbecker’s point is generally undervalued, especially in this branch of the woodworking community.
    For example, Paul Sellers often says that e.g. plane sole flatness is not as important as people make it out to be, but no one seems comfortable stating the tolerances for the work they produce.

    In one of his Mortise & Tenon magazine articles, Klein wrote that aprons/rails on pre-industrial tables might not even be planed at all, but just left rough from the saw mill.
    I think he actually performed a (very small) study of the precision of pre-industrial cabinets..

    (In fairness to Sellers, he usually shows us with his square etc, but either it doesn’t show on camera, or he is literally dead flat when he says he is)

    Edit: Found the Klein article. He claims surfaces in pre-industrial work has an average of 0.03 inch variation, although outliers are frequent and extreme.

    Sven-Olof Jansson

    An embarrassing, but suppressed memory, re-emerged today.

    I had the same problem for several years. Then, after I became a subscriber to WWMC, I learnt that not all planes come “ready to use from the box”. I put the plane in question on a straight edge. The photo shows a 0.3 mm gap, the maximum height of a concave bow stretching along the 385 mm (15″) sole.

    I believe that was enough for the plane to bite at the beginning of a stroke. With the whole sole on the board, there would be either no shaving or a reduced one. As the toe left the end of the board, the shaving would once again become thicker. Other planes, with flat soles, have not generated this particular issue.

    Non flat #5

    Sven-Olof Jansson
    London, UK; Boston, MA


    Are you getting a hump in the middle along the length of the board? This can come from applying extra pressure to start the cut and from applying extra pressure as you come off the board without realizing it. It is a useful exercise to let go of the knob completely before the nose reaches the end of the board and just push with the tote to convince yourself that you don’t need to push down to continue the shaving. Then, learn to deliberately unweight the front of the plane as you come to the end of the board. A different grip on the knob can help, too. See, for example, . Or, rotate the front hand so that the pinky is on top of the knob and the thumb and forefinger are pinching behind the knob (probably on the cheeks). Your elbow will likely be up in the air. This is an “old fashioned” grip you see in old photos sometimes. I find it reduces the tendency to push down at the end of the stroke.

    Extra pressure entering the board could be a habit, but could also be a sharpening issue.

    All this being said, even when your skills improve, there’s still a tendency to plane a hump into the length of a board. So, it pays to learn how to form a hollow. Simply put the plane down such that the mouth is about 1/4 of the way back from the middle of the board and push forward until the mouth is about 1/4 of the way ahead of the middle of the board and lift the heel of the plane as you push forward. This lift will cause the iron to come out of the wood and nip off the shaving. Repeat. After a few strokes like this, the plane will stop cutting because you’ve cut a hollow into the center of the board. It only runs for a short section of the board, though. You can extend the hollow by extending the cut a but back and a bit further forward progressively.

    If you play with this and get a feeling for how it works, you can start using this to counteract the tendency to plane a hump into the length of the board. Periodically make hollows in the middle, then return to working the length. You will find, when you go back to working the length, that you get a shaving at the start of the cut, then no shaving where you have the hollow, then a shaving on the other side of the hollow. As you work down, you will get a full length shaving. At that point, you will likely start making a hump again. If you have more thickness to take off, make another hollow and repeat. Don’t read this as a recipe that says you make hollows and then take off the ends repeatedly. I’m just trying to explain another pattern of planing you can use to monitor the state of the board and to adjust how the work is progressing.

    If I want dead flat, one of the last things I do is to reduce the plane set to a fine, fine shaving, put a hollow in the middle, extend it, and then work end to end until I get a continuous, fine shaving. I then stop. I can’t get flatter than that.

    As an aside, the more I plane, the more I find that I work on the bench top against a stop rather than in the vise. It is faster for me and the board is fully supported. It eats up bench space, but my bench is long enough and I now consider this a requirement.

    • This reply was modified 1 year, 3 months ago by Ed.
    • This reply was modified 1 year, 3 months ago by Ed.
    Scott Clausen

    Funny I found this now. I have some old reclaimed mahogany (I think) that is not thick enough to make the traveling joiners tool box. I have some cherry reserved for that. I decided I needed more practice first so I cut some old door panels up and removed the finish from one side for a box. This is the first time I have started this process with non S4S lumber. I flipped and went at the other. I did fairly well on two but the third I went very downhill on one end to the point it was no longer viable for a side but may do for a top or bottom. It may have had a low spot with the dark finish that I struggled to remove. I took a reasonably flat side and scribed a line around the board and got to work. When I planed to the line the board is of even thickness but now developed a slight cup. So many things to look at and check during the thicknessing process. I will stay at it, keep trying and pay attention as I go. I must say that I am getting a very good workout doing it this way. My electric jointer and planner are wondering if I am mad at them.

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