Chris Schwarz's Blog

How to Start a Woodworking Myth

cork_wedges_IMG_6039

There are so many old wives’ tales in our craft that you could write an entire book that lists and debunks them. Students constantly bombard me with them, and it makes me wonder: How do these begin?

After a slip of the tongue the other day, I think I have a good idea.

This week I’m assembling a Roman workbench and had a couple woodworking friends over as we drove in the 3” tenons into the benchtop and wedged them in place. The wedges were massive slips of oak that I’d cut earlier in the day.

The weird thing about my wedges was that they each had a thin layer of cork affixed to one edge.

“What’s the cork for?” one guy asked.

“Because the top is so wet and these tenons are so big, the springy cork will allow for some wood movement without the wedges splitting the benchtop,” I replied.

I was, of course, joking. The cork was there because it had been stuck to the piece of scrap I’d grabbed to make the wedges. But the response from the other woodworkers was heads nodding.

wedged_IMG_6042

Oh crap, I thought. So I quickly admitted that I was joking. The information was false. But my bullcrap had sounded good, and that was the problem.

Lots of times, students ask me “why” I am doing a certain operation. If I know the answer I tell them. But if I don’t know, I am quick to say: “I don’t know.” But I know a lot of people who won’t say “I don’t know,” and so they’ll generate a logical but false response. Here’s an example that I’ve heard first-hand many times:

Question: Why do you finish both sides of a tabletop?

Answer: To equalize the moisture exchange on both faces of the board to prevent the board from warping.

The answer sounds reasonable, but it’s completely the opposite of fact. And so the information is absorbed by the student and passed on. And because the information sounds logical, it’s almost impossible to stamp out the falsehood, especially once it’s written down.

So if you know nothing, say nothing.

— Christopher Schwarz

24 thoughts on “How to Start a Woodworking Myth

  1. rsz01

    So much for spending the time and money finished interiors that never see the light of day. What about veneering both sides of your substrate – same as other “wives tales”, or is this one fact??

  2. KAUnfried

    Experts are necessary my favorites are people like Chris here. They pass on there experience with out extra fluff. I appreciate comments like “my experience because it informs me that you have actually seen it. At least until you lie. Can’t wait till I get another of your books.

  3. martysmith

    I happened to read this blog post before I was headed out to visit some local antique malls. Coincidentally, I came across the book “Wood Construction: Principles-Practice-Details” (A project of the National Committee on Wood Utilization United States Department of Commerce) by Dudley F. Holtman et al. published 1929
    Wouldn’t you know this book also perpetrates the myth: “Uneven coatings on wood cause warping”
    Here’s a pic I snapped of the relevant pages: http://imgur.com/a/UObSU
    I guess this myth goes back a long long time.

  4. DLawson

    I spent the ’90s (give or take) hanging out in an online group devoted to urban legends, mostly picking them apart and debunking them. I was amazed at how many things that turned up as actual beliefs were things I’d heard as jokes 10-15 years before.

  5. drjohn1963

    I always thought that miraculous multiplication was a myth, but apparently my dad got a piece of the True Cross in his shop, and it multiplied into a million scraps of wood all over the place. Then I accidentally got one into my stuff, and the same thing happened to my garage. Good thing I know a scout troop that needs a lot of wood scraps…

  6. Rich

    With all respect to Bob Flexner, and to you, debunking a myth by citing an expert opinion is not my idea of an evidence based argument. You may be right or wrong regarding the need to seal both sides of furniture wood, but I need to see more evidence if I am to be convinced one way or the other. I have a suspicion, again based on no evidence (I just offer it as a possibility) that many traditional notions about moisture and wood movement arose in a time when dwellings were poorly protected against outdoor moisture and temperature change. Perhaps, in modern climate controlled buildings, some of the old measures, myths if you will, to ensure wood stability, are no longer relevant (?)

    1. Christopher SchwarzChristopher Schwarz Post author

      My evidence is from personally examining hundreds and hundreds of pieces that are finished only on the outside and have endured all sorts of environments for generations. Additionally, I don’t finish the insides or undersides of pieces and have never had any problems.

      The link to Flexner’s piece is merely a convenience for the reader.

      So I’m not just repeating Flexner.

      If you need more evidence, I suggest you performs some experiments for yourself. Or if you prefer academic pieces, read “Film Properties of Plastics and Elastomers” by Laurence W. McKeen, the definitive piece on the topic.

      1. Rich

        Thank you for the reference. I’ll see if I can find it. As for experimenting myself, I have, and I also have found no difference in performance between furniture sealed inside and out and wood treated on the “show side” only. But my experience is all with furniture made in my snug shop and used in modern houses. What I am wondering about is what my experience might be like inside a structure with a roaring fireplace, no insulation, dry winters and humid summers, perhaps a rammed earth floor. What about a medieval castle? In short, I have wondered if the myth, while not true for today’s circumstances, might not have been true in other times and circumstances. In answer, your examination of “hundreds and hundreds of pieces,” something I have not done, is testimony worthy of consideration and I thank you for it.

  7. Shaun Harper

    Truth or myth? Detensioning a bandsaw blade. You said in 2012 it was good for the saw and the blade. The more I have read that seems more myth than truth. Do you still detension your bandsaw?

    1. Christopher SchwarzChristopher Schwarz Post author

      Sometimes I do; sometimes I don’t. I’ve been trying to figure that one out myself. It’s difficult to know without long-term experimentation (blade life, etc.). I hope it’s myth because that’s one less thing I have to do.

      I got into the habit of it because it was my employer’s policy at the door factory. That’s the best reason to do it: So you don’t get written up by the boss.

      1. Shaun Harper

        I am a weekend warrior and it may be a few weeks between band-saw activities so I have no excuse not to detension. However I must admit I simply forget sometimes and if I know I am going to use the bandsaw a few days in a row I just leave it set with the tension. Again hoping it will not cause any stress to the blade/wheels.
        As always thanx for what you do for all of us

    2. Redbat

      Just an old man with an opinion. The band saw is my most used power tool in the shop. I love it. I have been using the same saw for over 50 years now, and have never released the tension on the blades. I have only broke 3 or 4 blades in the 50 years. As far as I can tell, the wheels are true and still balanced, and the rubber is still good. Is it luck, the saw, or just something you don’t need to worry about? When younger I felt guilty for not releasing the tension, after my heart attack and operation decided some one else could worry about it when they got the saw, as so far I haven’t had a problem, and probably won’t at my age. If so, I will fix it. Doesn’t solve the myth/fact issue however, just my opinion.

  8. Arkie

    Ask an expert “Why?” Definition of expert: “Ex” is a “has been”. “Spurt” is a “drip under pressure”. Way too many experts just repeat what the other person they considered an expert said. To find the truth, do it yourself. Then, you too, can be an expert! That’s why I have more respect for people like Chris who tries it rather than just believing it so.

    1. clemensj2

      As a “subject matter expert” in certain fields I do take personal exception to that statement. A true “expert” in a field has earned their expertise through experience, study, time in service, and extensive training. Most true experts do not hold themselves out as experts In a field, as they realize that there is plenty that the do not know or understand about a given subject. True expertise in a field can only be earned through hard work and time spent in the field.

      I will admit that in our society there is a plethora of so called “experts” that do little more than parrot information that they have heard and which seems to make sense. We as a group need to guard against such behavior.

      1. rjhanby

        As some one compelled to deal with subject matter “experts” on a regular basis, if all of you aren’t bifurcating idiots then the few of you who are not need to start throwing blanket parties for your moron brothers in arms. I have had many good teachers, none of them taught for a living, they had day jobs as physicist, engineers, programmers, or mathematicians (I obviously never had a good English teacher, spell checker caught all those day job names ). Likewise, I’ve learned a ton from other people working in my field, but every so called expert ever thrown at me was the result of some slick presentation given to management…

      2. dougzbanjo

        That being said, can anyone be considered a true expert in woodworking? There are so many different ways to do the same thing, and not one person will ever learn all of them. Maybe woodworkers are just experts at always learning.

    2. drjohn1963

      An actual expert can answer the question “Why is that?” because they have looked into it before they said it. If they can’t, then they have just parroted someone else, and are not really an expert. This also is the simplest test; ask “Why?” If they can answer, you have something you can work with. If they just fall back on credentials and authority, look for a better expert. Better than unadulterated anti-intellectualism.

COMMENT