Monday, April 11, 2011

Woodturning Basics

Woodworking 101

Woodturning Basics

by Scott Ollis

Traditional furniture and kitchenware often include turned parts. The parts are produced on a wood lathe. The wood is rotated about a horizontal axis while being shaped by a tool that is hand-held in a fixed relation to the wood.

The hand wood lathe combines the skill of hand-tool work with the power of a machine. Some woodworkers use a hand lathe for hobby purposes. In production work, its value is limited. The primary occupational value of this machine is for the pattern maker, the model maker, the bowl turner and those who restore and rebuild antique furniture and wood artists.

There are many accessories that can be used on the wood lathe, not only for turning but also for buffing, grinding, horizontal boring, disk sanding, drum sanding, thread cutting, and routing spirals.

The six most common types of tools for woodturning are:

  • Gouges for rough turning and cutting stock to round shape

  • Skews for smooth cuts to a finished surface

  • Parting tools to cut a recess or a groove

  • Spear-point or diamond point to finish the inside of recesses or corners

  • Flat tools for scraping a straight surface

  • Round nose tools for scraping a concave recess and circular grooves

Measuring tools should include a rule, dividers, outside calipers, inside calipers and a depth gauge.

There are two basic methods of turning wood: cutting and scraping. Cutting tools include the gouge, skew, and parting tool, while the scraping tools are the flat nose, the round nose and the spear point. All of the cutting tools can also be used for scraping operations. In the cutting method, the outer skin of the wood is pierced and a shaving is peeled off. In scraping, the tool is forced into the wood so that particles are scraped away. When only a limited amount of turning is to be done, the scraping method is acceptable.

The two basic types of turning are spindle turning and faceplate turning. Turning with the stock held between the headstock spur-center, with the grain of the wood running with the axis of the lathe is called spindle turning. When the wood is screwed to the faceplate, usually, but not always, the grain of the wood is run 90 degrees to the axis of the lathe and this is called faceplate turning.

Bowls, platters and many other circular objects are turned on a faceplate. To do the turning, the wood is fastened to a faceplate and shaped by cutting and scraping the wood. Faceplates commonly used are the screw-center and standard faceplates of various diameters. The faceplates have screw holes for fastening the wood in place.

The first step in faceplate turning is to determine the size and kind of material needed. To make a larger bowl or platter, it is often necessary to glue up the stock. For a square object, carefully mount the wood on the faceplate. If the object is to be round, first cut the stock on a band-saw to a disk shape about one-quarter larger than the intended finished diameter and about one-quarter thicker. Then mount it to the faceplate.

If screw holes on the back of the bowl or platter are objectionable, cut a piece of scrap stock at least 1" thick and about the same size as the base of the project. Screw the faceplate to the scrap, glue the wood to be turned to the scrap, and you are ready to turn.

There are several ways of applying a finish to a turning. A simple method is to apply paste wax to a cloth and hold it to a revolving turning so that it is completely coated with the wax. After approximately 10 minutes, run the lathe at a slow speed and polish the surface with a soft, clean, dry cloth or paper towel. A second coat can be applied if needed, using the same method. To apply a French polish, fold a piece of linen cloth into a pad. Then add one teaspoon of shellac and add several drops of boiled linseed oil. Hold it to the revolving turning while moving the pad from side to side until the desired results are achieved.

Most importantly, have fun while turning!