You might say, what’s the big deal about turning a bowl in about 3 hours time, anyone can do that! Well in this project we will instruct you on how to turn a bowl while it’s green, dry it, finish it, all in just a few hours. John Wolf (from the Turning Tuesday’s woodworkers) shows us how it’s done starting out with a piece of “green” curly maple saved from the scrap pile.
The raw material is a slab from a curly maple log, although any fresh piece of “firewood” will work. Be sure that the wood is free from cracks, knots or other defects.
This piece was cut slightly over 8 inches in diameter. John tells us, “I temporarily and loosely nailed a circle of cardboard to the bark side to serve as a template to aide in bandsawing the blank into a relatively round shape.”
“Once this is done, remove the cardboard template and flip the piece over. Mark the center of the bowl blank with the template you just used. I used the ½ inch diameter screw center that came with my Oneway Talon Chuck to hold the blank on the lathe.”
“Consequently, I drilled a one inch deep 3/8 inch diameter hole in the center of the blank. Be sure to do this on the flat surface that was against the bandsaw table when you sawed out the blank. Then screw the blank onto the screw center. A small face plate will work well too if you don’t have a screw center.”
“The turning is rather straight forward. Using a Crown Pro PM 5/8″ Turning Gouge, I turned the edge true, then moved the tool rest and turned the bottom including shaping the outside of the bowl using a 1/4″ Pinnacle Cryogenic Bowl Gouge.”
I then prepared a tenon for holding the blank in the chuck to allow turning of the inside contour of the bowl. It is quite important that the bowl be thin – less than ¼ inch wall thickness throughout – including the bottom. Don’t be afraid of this requirement. Remember, this is just wet firewood we are working with. An “Oops” is just a learning experience.”
“Once turned (in approximately 20 minutes), I sanded the inside and outside. Once you are satisfied with the sanding (I usually go down through the grits finishing with 600), reverse the piece and finish the bottom.”
“Remember that it needs to be as thin as the sides of the bowl. I used my vacuum chuck, but the job can be accomplished with a Longworth Chuck, a jam chuck or other methods for holding the bowl.”
“The turned and sanded bowl is still quite wet. You could put it in a paper bag and set it in the corner of your shop for several months to dry, but what fun is that! I put the blank in the microwave oven and heated it on high for about 40 -45 seconds”
“You want the bowl to be steaming (but not on fire) when you take it from the oven. Remember, it is hot! I put it on painter’s pyramids to allow air circulation around both the inside and outside of the bowl.”
“After the bowl cools to near room temperature, put it back in the microwave and “zap” it for about 25 seconds. This time it should be quite warm but not as steaming hot as the first time. Keep repeating this cycle until the bowl is no longer loosing weight when measured on a kitchen scale. The number of microwave cycles required to make the bowl dry depends on the species of wood, its initial water content, and the thickness of the bowl, in this case I repeated the microwave drying cycle 6 or 7 times.”
“Once the bowl is dry you will notice that it is no longer round. It becomes oval with the end grain to end grain dimension being longer than the long grain direction. The bottom may also be somewhat out of level. It so, simply rub it back and forth over a sheet of sandpaper that is on a flat surface such as your saw table or a surface plate.”
“The bowl may need a brief bit of hand sanding before finishing. I like the 320 of finer foam backed paper for this task. Apply the finish of your choice. I used a combination of 75% shellac and 25% linseed oil mixed together with a Japan Drier to hasten the drying of the linseed oil.”
The Woodcraft Adventures Blog would like to express it’s thanks to John Wolf for this turning project, interview, content and for all his continued support of Woodcraft, and all the guys at “Turning Tuesdays.”
We’ll be back from time to time with more from “Turning Tuesdays” at Codger Lodge.
auf Wiedersehen…Frank!