You know those people who wear t-shirts with “I Love Wood” printed across the chest? Perhaps you are one of those people – it’s okay, I’m not making fun. Even if it is not a part of my wardrobe, I, and hopefully all woodworkers, share the sentiment. Wood is great for a lot of reasons – of course. The thing is, and this rarely gets expressed in t-shirt form, wood is also one of the most obstinate, frustrating, temperamental, and, well, horrible materials to work with. Everybody knows that too. Here is my little story about wood’s dual nature.
Back on Election Day of 2008 I began work on a pair of mahogany cradles for the 2009 Working Wood in the 18th Century Symposium (bedroom furniture was that year’s topic). The idea was to take this beautiful piece of mahogany, 8′ x 20″ x 1 1/2″, and break it down into two 4′ lengths and then resaw each of those sections for the sides and ends of each cradle.
Here’s the rough-sawn mahogany board that was supposed to yield head, foot, and side boards for two cradles. This board was well seasoned and had been in our inventory for about twenty years at this point. Though rough in texture, it was remarkably free of cup, bow, and twist.
It took about two hours to resaw each of these four foot lengths – or roughly one half hour per foot. We thought that was a pretty good speed – twenty inches is a lot of width to move the frame saw through and such wood is best not treated cavalierly. This is marathon sawing, not sprinting.
Here, former journeyman cabinetmaker and current joiner, David Salisbury and I resaw the first of two four foot lengths. Notice the wedges to open up the kerf a little bit.
Almost there! After making our way through a little over half of the board’s length we flipped it end for end in the vise and started sawing from the other direction. Things seemed to be going very well…
Sometimes with resawing, as with all sawing, things start to bind as tensions in the wood reveal themselves. We noticed a little of this with the first board and placed wedges in the kerf to open things up (as is visible in the second photo above). The second board seemed to have a good deal more tension. When things really start binding and the saw seems to be fighting with me, I normally assume I am doing something wrong, or, with this saw, that the other person is doing something wrong (sorry other person, but you probably blame me too). In truth this is one of the greatest difficulties with a two-person frame saw: if the two sawyers are not completely in synch, things start binding. When this happens we troubleshoot the problem, make corrections, and saw forth. If no corrective measures work then we start to worry about the board being ill tempered. We drove our wedges deeper and kept cutting.
With the sawing complete and the boards given a few days to adjust to their new thickness, I commenced to plane them flat and smooth. Head, foot, and side boards were all coming along nicely until I learned that it wasn’t bad sawing that caused all of that binding. It was something in the wood. Of the four boards produced by the resawing, three were beautiful and well behaved while one was decidedly difficult. That 4′ x 20″ x 5/8″ board developed a horrible bow, cup and twist. I planed as best I could, but there was no way to remove these defects and keep my thickness. Before rejecting this piece – it was pretty enough for more effort – we decided to wet and over-clamp it in an effort to bring it back in line. (N.B., this technique deserves a full explanation in a separate post.) This worked, but after a few days the board sprung back to its deformed state. Perhaps more water and more clamping would do the trick. Nope. By this point we had decided extraordinary measures were needed to make this board flat. If damp rags and over-clamping worked on occasion, perhaps it was time to make use of that stream that runs under the shop. In early 2009 I pulled out a nonpartisan and timely pun to make this thing conform: water boarding.
We saturated this board by submerging it in the stream outside the shop for a day. Surely we could make it give up the bow, cup and twist.
After a week of aggressive over-clamping we had a much flatter board. Over another week of waiting we watched some irregularity creep back in. At this point, I decided to make a go of it and cut out two cradle sides. They nested together in the board in this way:
The two cradle sides nested together in the board like this.
Most of our trouble was in the middle of this board. Some of it got cut out, but most of it came right back after the sides were sawn apart. For reasons other than this piece of wood, I decided that one cradle was enough and went back to worrying about cutting compound angled dovetails (more on that in a future post). These two cradle sides have kicked around the shop for the past five years and in a flurry of spring cleaning I came across them again. Here is the cradle that I made from this beautiful piece of mahogany:
Mahogany cradle constructed by the author (2009).
Here’s the cradle I didn’t make out of that same beautiful piece of mahogany:
It was not supposed to be a Bombay cradle.
I bet someone can explain this scientifically, but for most of us this is the nature of our chosen material, indescribably beautiful and infuriatingly difficult. The sides of the good cradle were cut from the same section of the original board as the bad sides: they were essentially book-matched. How could one half of that thickness stay so flat while the other went so wonky?
I don’t know, but I do know to account for surprise. It is part of the job.
I love wood!
Yeh, I #@$!%& love wood.
Maybe something like that last sentiment should be added to the back of those t-shirts…