Wood Selection
Almost every hollow form I turn is from local hardwoods and is turned green.
Why use green wood? Green wood is relatively inexpensive, easy to obtain, and easy to turn. It is nearly impossible to find, or afford, large kiln dried wood suitable for turning large pieces. Construction sites, firewood cutters, arborists, and landscape recycling centers are all excellent sources for wood. The biggest problem I have with green wood is my greed. I bring home more wood than I can use.
When harvesting fresh wood, the first step is to remove the pith. This is the very center of the log and has the most stress. I try to keep the wood in as large of pieces that I can manage and store. The larger pieces allow more flexibility in how the wood can be used in the future. I will coat all the end grain with Anchorseal.
The greatest advantage of harvesting my own wood is I am in control. I can orient the piece based on grain, color, and defects by cutting away the unwanted areas. Since this is inexpensive, I don’t feel guilty about wasting wood. I’ll waste as much wood as necessary to get the desired blank. Do not look at a log and try to figure how many pieces you can get out of it in order to maximize. Look at the log and discover the one or two prime blanks.
One of the biggest traps in wood turning is using expensive and exotic woods. Most of the pieces all look eerily similar to the original block of wood when finished. We become shy when cutting expensive wood, are fearful we will ruin the piece, and don’t want to cut away all the beautiful grain.
The most important aspect of any vessel is its form. The form is the skeletal backbone of all other aspects; grain, color, finish, texture, size, and so on. A piece with perfect form painted black looks better than a piece with killer grain that has poor form. Therefore practice your form on inexpensive, disposable wood until you can cut the perfect form – then apply these skills to the perfect wood with killer grain.
“Green wood always cracks and distorts…”
Uneven moisture loss in wood will cause it to crack and check. Turning hollow form vessels relatively thin and relatively even wall thickness will allow it to dry at an even rate. The piece also needs to be turned from start to finish in a couple of hours or less.
Most woods will dry just fine with even wall thickness somewhere between 3/16” to 5/16”. Vessels with wall thickness between 3/8” to ½” should be placed in a paper bag for a few days to slow the drying process.
As wood dries it will shrink and move. The amount of shrinkage depends on the orientation of the grain. Wood shrinks along the length of the grain approximately 0%, radial to the log shrinks about 4%, and along the growth rings about 8%. This knowledge helps predict how a piece will distort as it dries. David Ellsworth is a master getting great, predictable movement in his pieces. Most of my vessels are turned from end grain. This grain orientation has the least amount of distortion. I do not mind some distortion in my finished pieces. I believe it adds to the organic look and feel.
The next class we will mount some wood on the lathe and begin the shaping.