Writing Sample

Below you will find a writing sample that was completed for an assignment in a technical writing class. The assignment involved identifying a specific process, breaking it down into steps, and creating a set of detailed instructions designed for a specific target audience.

How to Turn a Bowl on a Lathe

By Joseph Somerville

Woodworking is a fun an exciting hobby that can be useful as well, but the world of wood turning takes it to new heights. While most wood turning today is done for decorative or ornamental pieces, it is nevertheless a fun and rewarding hobby. This guide will describe the tools and materials required to make a bowl, step-by-step. We will also discuss terms that you may not be familiar with, as well as safety precautions.

Required Tools and Materials

• Wood Turning Lathe
• Bandsaw
• Bowl blank
• Bowl gouge
• Parting tool
• Faceplate or worm screw
• Chuck
• Sandpaper
• Face shield
• Dust Mask
• Optional: Scraper, calipers

Safety Information

• Always wear a full-face shield when using a lathe.
• Never wear loose fitting clothing or jewelry when using a lathe. If you have long hair, tie it in such a way that it cannot fall near the turning surfaces.
• Read the manufacturers instruction manual and always follow recommendations.
• If possible, have an experienced wood turner on hand to guide you, as getting the feel for wood turning is easier when you have an experienced helping hand.
• If you are turning a dry bowl blank, wear a dust mask, especially when sanding.

Quick Start Guide

1. Select a bowl blank.
2. Cut the blank into a circle.
3. Mount the blank centrally using a faceplate with screws, or with the worm screw.
4. Turn the outside edge to a perfect circle using the gouge.
5. Shape the outside of the bowl with the gouge.
6. Refine the outside and sand using successively finer grit sandpaper.
7. Shape the tenon of the bowl to the angle of your chuck jaws.
8. Check that the tenon fits well into the chuck jaws.
9. Remove the bowl from the faceplate and mount into the chuck.
10. Shape the inside of the bowl using the gouge.
11. Refine the inside shape and sand using successive finer grits.
12. Using a finish such as friction polish, wax, or shellac apply a finish to the entire bowl.
13. Use a parting tool to separate the bowl from the tenon. Alternatively you may cut the tenon off with a handsaw, or sand it with a belt sander.
14. Sand and apply finish the bottom of the bowl.

Glossary

• Lathe – A machine that holds and turns a workpiece at a high rate of speed. A tool rest is used to prop a cutting tool on, which shaves material off the rotating workpiece.
• Faceplate: A flat metal plate that attaches to threads on the lathe. The workpiece is mounted to the lathe using the faceplate.
• Chuck: A device that attaches to threads on the lathe. The chuck has movable jaws that tighten and clamp the workpiece to the lathe.
• Bowl gouge: Woodturning tool that is shaped in such a way as to not catch on the quickly changing grain direction of the wood blank.
• Parting tool: A sharp edged tool that is used to separate a work piece from the material that is held in the chuck.
• Bowl scraper: A tool used to make fine adjustments to a workpiece, taking very light shavings to achieve a perfectly smooth finish.
• Calipers: Used to measure the thickness of a material. In this case used to check the uniformity of the walls of the bowl. Tenon: A section of wood that sticks out at the bottom of your bowl. It is used and shaped to fit properly into the chuck.

Steps

Step 1) Select a bowl blank.

When selecting a bowl blank, a good wood for beginners is maple, but any hard wood may be used. Typically bowl blanks sold in woodworking stores are dry and therefore produce a great deal of dust when turning them, therefore a dust mask should be worn to prevent inhalation of particles. If you do not have access to a local shop that sells bowl blanks, you may purchase one online, or simply cut one from a log of a locally felled tree. This is a topic in and of itself however, and I recommend buying a precut blank to start.

Step 2) Cut into a circle.

Using a compass, draw a circle roughly to the edges of your blank. Using a bandsaw follow this line to the best of your ability. It is not important to be perfectly accurate, as the bowl will become perfectly round when turned on the lathe.

Step 3) Mount to faceplate or worm screw.

You may either use a worm screw or a face plate for this step. If you are using a worm screw you will need to find the center of the blank and make a mark. Next, use a drill bit slightly smaller than your worm screw to drill a hole no deeper than the worm screw itself. With the worm screw mounted in the lathe, screw the blank onto the worm hand tight. If you are using a faceplate, simply center the faceplate on the blank and using screws secure the bowl blank to the face plate. This can be done with the faceplate disconnected from the lathe. Once it is secure mount the faceplate with the bowl blank attached to the lathe.

Step 4) Refine the outside edge.

Previously I mentioned that you did not need to cut the blank to a perfect circle on the bandsaw. This is because we will end up with a perfectly round bowl now. Using your bowl gouge take shavings off the outer edge of the bowl until it is perfectly round. You can brace your hand against the tool rest as a guide. With this method we will end up with a sufficiently round outer edge.

Step 5) Shape the outside of the bowl.

Some guides tell you to use multiple types of gouges to shape different parts of your bowl. However, I recommend you simply stick with the bowl gouge. The bowl gouge is shaped in such a way that minimizes the risk of a “catch”, which is where the tool digs too deeply into the grain of the workpiece and rips the turning tool from your hands. This will startle you, but it usually not dangerous. By using a bowl gouge we can avoid this in most cases by taking light passes and not trying to remove too much material at a time. Start at 200-400 RPM. We want to increase the speed until the lathe just beings to shake. Once this happens turn it down by several tens of RPMs. This is the speed we will turn at. Turn the outside to your desired shape.

Step 6) Refine the outside. Now is the time to perfect the outer shape of your bowl. If you are happy with the smoothness and shape, simply move on to sanding. Otherwise you may use the bowl gouge or a scraper to perfect the shape until perfectly smooth. Once complete use successively finer grit sandpaper with the lathe turning at a few hundred RPMs to sand your workpiece.

Step 7) Shape the tenon. Using a parting tool, shape the tenon(what will become the bottom) of your bowl roughly to the same size and shape that can be accommodated by your chuck jaws. The jaws of your chuck need to be able to close firmly around the tenon to turn the inside of your bowl. Try to match the profile of the jaw. If your chuck has removable jaws, you may hold it next to the workpiece to try and match this profile. While it does not need to be perfect, it does need to match closely to be secure.

Step 8) Check your fit. Before removing the bowl from the faceplate, make sure that your chuck fits on to the tenon that you have created. From personal experience I can tell you that this step is worthwhile. Nothing is more frustrating than turning the tenon, removing the blank from the faceplate, and then having the tenon too small or too large, so check that it fits now.

Step 9) Mount your blank on the chuck. Remove the faceplate from the lathe with bowl still attached. Now remove the screws holding the bowl to the faceplate. Now attach the chuck to the lathe making sure it is snug and tighten any set screws (refer to the chucks manual to check and see if it has a set screw). Using whichever method your chuck utilizes secure the bowl to the chuck and tighten well.

Step 10) Shape the inside. Using the same method as before turn the lathe on and turn the speed up until it is just below where the lathe will vibrate. Use your bowl gouge in smooth, light cuts to remove material from the inside, taking care to keep the wall thickness as even as possible. It is important to remember that your tool will cut much faster toward the outer edge of the bowl than the middle, as the middle of the bowl is turning much slower than the outside.

Step 11) Refine the inside. Like in step 6, we will refine the inside surface of the bowl. Unlike the outside however, the inside is more difficult to get perfectly smooth. Do not get discouraged if you find that you need an excessive amount of sanding. You can always pick the bowl gouge back up to remove and bumps along the surface. You may want to use calipers to check that the wall thickness is even from the top to the bottom of the bowl. Once you are happy with the surface and shape, use successively finer grits of sandpaper to get a perfectly smooth texture.

Step 12) Apply finish. There is a great deal of discussion about the best finish for a wood bowl. For now we will not be overly concerned with perfection. I recommend friction polish, which can be purchased at your local woodworking store, or online if you do not have access to one locally. Friction polish is great because it produces a wonderfully smooth surface, and a slight shine that will enhance the natural grain of the wood that you have used. To apply friction polish use either a heavy-duty shop paper towel or some type of cloth that will not leave behind fibers. Apply the friction polish to the cloth and with the lathe on and turning a few hundred RPMs press the cloth onto the wood. Use significant force here so that the cloth heats up, which will set the polish onto the wood, and form a nice shine. Make sure to cover the entire surface going section by section.

Step 13) Remove the bowl from the tenon. Use a parting tool to separate the bowl from the tenon right above where the bowl is attached to the chuck. With the lathe turning around 800-1200 RPMS slowly advance the parting tool with it set on the tool rest toward the bowl. Use as straight of a motion as possible so that the parting tool does not turn and catch on the wood. Alternatively if you do not have a parting tool you may remove the bowl, tenon and all, from the chuck, and simply use a hand saw to remove the tenon from the rest of the bowl. After the bowl is separated from the tenon, sand the bottom of the bowl, and apply your finish.

Wrapping It Up

In conclusion, turning a wooden bowl on a lathe is a fun and rewarding experience. Although proper safety precautions must be taken, with patience and effort this is a relatively simple project for those that have the required tools and materials. We can boil the process down to shaping the blank, mounting the blank, shaping the inside and outside of the bowl, and applying a finish. The final product will be a unique and even useful item that will last for years to come.