I just finished making a square, natural edge bowl and thought it would be interesting to share the process. A lot of people I show my work to seem impressed, but mystified as to how it is done. Explaining that it was turned on a lathe often doesn’t help as many people don’t know what a lathe is.
A lathe is simply a fancy carving device. However, unlike most people’s vision of carving, where the work piece is stationary and the carving tool is moving, when turning on the lathe, the workpiece is moving (rotating) and the carving tool is stationary. Because the lathe rotates the workpiece around a pivotal point, most work that is created on the lathe, is inherently round.
Hopefully this pictorial essay will shed some light on the process for those not familiar with it. While the bowl that I made here is not a standard bowl, the overall process is very similar to that used in creating a regular salad bowl.
While this may look like a hunk of firewood to most, I could see a bowl inside waiting to be exposed.
A rough sketch on the log outlined the bowl and the extent of the wings. As I am not able to turn anything greater than 16" diameter on my lathe, anything outside of the two straight lines needed to be cut off before I could mount the log on my lathe.
The log cut to size on my band saw.
A faceplate was securely screwed to the log at the center point of the bowl. This will be the top or inside surface of the bowl.
The face plate was then threaded onto my lathe, exposing what will become the bottom or underside of the bowl.
With the log being rotated at speeds varying from 250 to 800 rpm, a cutting tool or gouge is used to shape the underside of the bowl and the wings. Extra care needs to be taken cutting the wings as the gouge is alternately "cutting" wood and air. Awareness of where your hands and fingers are is a necessity.
With the shaping done, the underside of the bowl and wings are sanded smooth using both power sander ...
... and good old fashioned elbow grease 🙂 Note the tenon that has been formed on the underside of the bowl. This is temporary and will be used to attach the bowl to the lathe so that the inside of the bowl can be hollowed out.
A coat of shellac is applied as a sanding sealer. You can already see the inner beauty of the wood shining through!
The log is now turned around on the lathe and the tenon I mentioned earlier is gripped in the jaws of a chuck.
The faceplate is now removed.
Throughout this process I have been constantly returning to my grinder and resharpening my bowl gouge so that the wood can be cut cleaning and efficiently with a sharp tool. Pretty cool picture with all the sparks flying 🙂
With the lathe once again rotating the workpiece, the inside of the bowl is now hollowed out.
While hollowing the bowl careful and frequent measurements are made using a home made laser depth gauge. I want to make sure that I don't end up hollowing right through the bottom of the bowl. The goal for today is to make a bowl, not a lamp shade!!
Once the hollowing is complete, the inside of the bowl is sanded smooth ...
... and the wings of the bowl are sanded gently by hand. I could have also turned the top surface of the wings smooth, but I chose to leave them showing the rough texture of the chain saw marks from when the log was cut up. I like the contrast in texture between the chain saw marks and the smooth inside surface of the bowl.
A coat of shellac sanding sealer is applied to the top surface of the bowl and the wings.
The bowl is once again turned around to allow me to remove the temporary tenon on the underside. This time the bowl is held to the lathe by means of a chuck which generates a vacuum. It is amazing how much pressure can be generated by the vacuum and how securely the bowl is held.
With the tenon turned away, the bowl is removed from the lathe. I sign and number the bowl using a wood burning pen.
Then the bowl is flooded with an oil finish. The oil is allowed to penetrate the wood for 10 to 15 minutes before the excess is wiped off. It is then allowed to dry for 24 hours before the application of a second coat of oil. Once cured, the oil both protects and enhances the beauty of the wood.
The finished bowl.