The humidity drops to desert-level lows in New England during the wintertime. Our pine floors become gappy, and the old frame-and-panel doors throughout the house close a little bit differently than they do in the summertime. Wood is hygroscopic, constantly absorbing or releasing moisture in response to changes in humidity and temperature. And when moisture leaves, wood shrinks. This can cause all kinds of interesting problems if you’re a boatbuilder, a cooper, or if you happen to swing a hammer or axe.
Many of my wooden-handled tools seem just a little loose right now – not dangerously so, but enough to be aware of it. I find myself thumping the bottom of my hammer on the benchtop before using it, just to keep the head feeling secure. This is only a small nuisance, but other tools offer more concern. For example, few things feel as dubious as swinging an axe with a loose head – this is, in fact, a seriously bad idea. Thoreau, who borrowed an axe to build his cabin on Walden Pond (it’s also a seriously bad idea to lend out your axe, by the way), experienced the thrill of having the head fly off the haft one day. To fix the situation, Thoreau “cut a green hickory for a wedge, driving it with a stone, and…placed the whole to soak in a pond-hole in order to swell the wood.” I cringe, even just typing his description, because it describes a perfect-storm scenario of preparing to launch that axe head deep into the woods (or your neighbor’s torso). A green wedge will shrink; soaked wood may be tight at first, but the cells of the wood become crushed in the eye of the axe – when the haft dries it will be looser than ever. But Thoreau managed to fell and hew all the timbers he needed with this axe. His secret may have been a trick that I sometimes employ – cutting an over-long wedge.
When a wedge is left long (maybe protruding 1/2” or a little more beyond the head), it can be driven further when the head loosens, locking things tightly together again. Eventually the tool reaches a stasis where the handle will shrink no further and the wedge is sufficiently tight to hold. It can then be cut off flush. Obviously, you cannot glue the wedge with this method.
Another traditional solution that often works is soaking the end of the tool (the top of the handle) in linseed oil. This oil will saturate the cells of wood, like water, but it won’t evaporate away and cause the cells to shrink down again.
As a last resort, I sometimes drive a little metal cross-wedge into the end to give just a little more hold in the eye. I’ve seen some terrible examples of taking this method too far – axes filled with screws, nails, bits of pipe, broken drill bits, you name it, all driven in to try to get rid of the wobble. I guess it works, but it ain’t pretty.
Of course, this will all be a moot point when spring arrives and brings with it warmer weather and moisture in the air. Those loose handles will tighten up all on their own, as if by magic.
–Mike