The Fuzzy Bits

I had a good question on Instagram the other day regarding turning green wood and how to avoid the “fuzzy bits.” I gave a long answer for Instagram, but the subject deserves more space. So here are my thoughts on this topic, to date:

There are a lot of wonderful aspects to turning green as opposed to dry wood: the workability, the reduction in dust, the way the wood moves as it dries, etc…. It is definitely my preferred medium. But it does come with challenges: cracking, excessive warping, and oxidation to name a few. One major challenge, for turners of both wet and dry wood, is producing a smooth finish right from the gouge or hook.

When turning side-grain oriented bowl blanks, twice every revolution your tool is cutting against the grain, or is cutting wood that is unsupported by the fibers behind the cut. In these quadrants the tool is lifting fibers before cutting them off, leaving sort of a “buzz cut” effect in the wood. Once you pas this uphill section and get into side and cross grain again, the wood fibers are supported and you can cut them cleanly. My commenter on Instagram was wondering how I reduce the roughness of the “fuzzy bits.”

First, this is a problem with which both green and dry wood turners struggle. For those turning dead dry wood, it is less of an issue: dryer wood cuts a bit more cleanly than green wood, so the final surface is definitely smoother. Dry wood also sands reasonably well, and if that is your thing you can sand away those rough patches. Green wood does not sand nearly as well as dry, so you really don’t have that option, though I do lightly sand my work with 180 grit.

Thus, one part of your solution to avoiding those rough patches when turning green wood is not to turn completely fresh wood. Let is rest for a bit. How long depends on the species. Some old-time turners often talked about felling beech logs and only turning them once the bark had started to separate from the wood. If you are going to let your wood rest before turning, watch out for a few issues. If you leave the wood on the ground in a damp place, watch out for spalting; it can be beautiful, but it can also undermine the wood integrity. And the fungus in spalted wood is nothing something you want to inhale a lot of. Rapid drying and checking should also be avoided. Some people paint the ends of their logs to slow moisture loss, but I find simply elevating the log off the ground and keeping it in the shade and out of wind works best. And be careful with birch; the bark is nearly waterproof, which traps moisture in the wood and accelerates rotting. If you want to let birch mellow, consider peeling the logs first.

The second consideration is the wood species. Some species are more prone to fuzzing than others. For example, fresh birch can definitely get furry, but fresh beech turns reasonably well, usually. I say “usually” because each tree is different. If a tree grew in stressful situations, say on a hillside or buffeted with lots of wind, the fibers can interlock, tension can build in the wood, and the surface can be quite rough. Also, where in the tree matters. The first three feet of a trunk, while marvelously large in diameter, is under tremendous stress. Think of how much a whole tree weighs, and consider how much strain it’s base bears after years of blowing in the wind…. This wood warps a lot when drying, and can be very fibrous. For these reasons I am carful with how I use those first few feet.

Another aspect to consider are your tools and the way you present them to the wood. Generally, sharper tools moving more slowly over wood that is spinning faster produce a finer finish, so if you are struggling to create a smooth surface sharpen your tools, slow down your cut, and crank up your speed. The type of cut you make also creates very different surfaces. For example, on an electric lathe a pull cut moves wood pretty quickly can leave a “plucked” surface. Same with a scraping cut. Push cuts, on the other hand, leave behind a lovely, smooth surface. Same with a sheering cut. And in general, lighter cuts produce a finer surface than heavier cuts. Finally, often the quality of the cut can be changed by altering the angle of the tool’s attack on the wood. Try dropping the handle, angling the tool up more than you might normally, and see what it does to the finished surface. Of course, all of these cuts change a bit depending on whether you are working the inside or the outside of the bowl. For example, I would avoid a scraping or sheering cut on the inside of the bowl!

Hope this helps.