25 Comments

  1. I’ve a question Paul. When the board has wild grain as the one has towards it’s end, sometime reversing, etc, does wood movement follow along the width of the board the same during the better long grain area, as where the board has the wild reversing area. I wonder if when glued to a good straight grain board will the over all expansion or contraction be effected by the knotty/gnarled area, thus inviting a split table top? Thank you
    Boyce

  2. Paul, I have another question about wood movement. Does it matter which way the table top boards are running? I have seen some tops with the boards running long ways so the expansion will be against the longer side aprons and other table having the top running from side to side so the expansion would be against the shorter aprons at the ends of the table.

    1. Hi: Wood will always shrink and swell in use, as it equilibrates with the environment, and it cannot be prevented, although you can slow it down somewhat with finishes. I think it’s great that Paul stresses the use of correct technique, because if you try to defeat wood movement, your project will fail.
      Regarding tables with the boards going across the short side, rather than along the length, I think it is important not to glue the skirt to these boards to allow free movement of the top, otherwise you will get into trouble with cracks and so on developing. You can consult the online wood movement calculator (by species) on woodweb here:
      http://www.woodweb.com/cgi-bin/calculators/calc.pl?calculator=shrinkage

      Obviously, when you have your table boards arranged along the short side of the table, the amount of movement is going to be much greater, since it is the width (and also thickness) that changes (the length changes are negligible). These are all estimates, since all organic material will have significant differences in cell size depending on the growing conditions etc. There is very significant variation from board to board- even from the same species, and even from the same tree- in the amount of moisture it will pick up. I’m sure you have experienced the fact that two pieces of wood of exactly the same size and species (maybe the left and right stiles or something) might have significantly different weights- ie different densities- even though they are at equilibrium with your environment, so they will react differently to changes in moisture.
      How the wood is prepared from the tree is also important- ie whether it is FS or QS, since the quarter sawn will only move about half as much as the regular flat sawn wood. In other words, tangential movement is roughly twice as great as radial movement for a given increase in moisture content. I tested a bunch of specimens when I was in Engineering school, and there was quite a bit of variance in the measurements using sensitive measurement devices. Wood moves, and you have to make allowances for that, just like the craftsmen of ages past did.

  3. Excellent information Paul. Some time ago I did some quite a bit of jointing in oak, just with 2 hand planes, it was a huge battle between me and some strange grain parts of the wood but at the end everything turned ok. It was very scary anyways.

    1. I have a veritable scrub plane, and have found it extremely useful. Recently I helped a friend surface a large walnut burl. He was using a #5 with a heAvy camber, and had really hard work to push it through. With the scrub, we were able to hog off a lot of very hard and gnarly burl in a hurry, and with less fatigue than the wider cambered blade.

      Based on this experience I tend now to take the worst off with the scrub, then go to the cambered jack before moving to a jack or smoother with a flat edge.

      I may also try a beater #3 with a cambered blade at some point.

      Many roads to smooth, anyway.

    2. I have a 40 scrub plane and a #5 set up as a scrub and prefer the #5 because it is so much wider than the 40. I’ll bet it is the same with a #4, which also would be wider than the 40.

  4. Well I’m not stupid, but I have always brought the whole board four square before cutting my parts. What a revelation to realize how much waste I generated in doing so. Cutting your part from the rough is so much more efficient.

    Always a kernel of knowledge to be kept from each of these videos.

    Thank you Paul, I will still sit at the feet of the master.

  5. Love these stock preparation videos! Thank you, Paul! When reading the grain, a couple of times you mentioned that sapwood wood have to be discarded. Just wondering why that is, why is it not desirable? Thank you.

    1. Sap wood is not yet fully formed and deceased wood. In most woods the structure is therefore very different than the heartwood and has different working properties as well as levels of density, durability and so on. It is also where there is the life-giving property that beetles and fungi thrive in so there is the added risk and even probability that this outer layer becomes host even after the wood has been seasoned and dried. It usually retains it’s lighter colour and so these issues make it unpredictable, often un-stainable and the shrinkage rate is different so after a period the difference between the heartwood and softwood say on a tabletop becomes discernibly uneven.

  6. Hello Paul… first, Thank You and your team for all your videos.

    A tiny tip for you about that chalk line:
    You only need a small amount of chalk in the chalk box.
    Point the tip downwards, when you roll In the line, to “chalk” it.
    When you roll the line out, you hold the tip Up, to prevent the chalk spilling.
    I sometimes only “chalk” the line for every second use.
    Greetings to all, from me Jakob and Sir Newton.

  7. Once again, an excellent teaching set, Paul. The very best part for me is the running commentary on what is going through your mind as you examine and think about each raw board and what it can be applied to. Thank you for passing on this wonderful, useful knowledge on how to read wood. All the best to all at WWMC.

  8. Well I am blessed with a 18″ plainer so making them square and the same dimensions are easy.
    The only problem I am having is no audio on windows 10. Any suggestions? PS: audio works on all other playbacks on other web sights.

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