Turning the inside of the bowl
Remove the bowl from the lathe, fix the chuck to the lathe with the appropriate jaws for your spigot / recess and mount the bowl in the chuck. Ensure the bowl is centred and firmly held by the chuck. Position the toolrest and again rotate the lathe spindle by hand to ensure the toolrest does not hit the bowl. This is especially important with natural edge bowls. Also remember to start the lathe at a low speed and increase progressively. Mounting an out of balance natural edge blank this way round will probably cause more vibration because the centre of gravity of the piece of wood is now farther from the headstock.
If the top of your bowl is going to be flat (as opposed to a natural edge), take a few cuts to even it up before proceeding to hollow the inside of the bowl.
For hollowing end grain bowls, cut from the centre to the outside wherever possible. It is often easier to take the bulk of the wood out cutting from the outside toward the centre but the downside is torn grain. If this is done, the final cuts should be made from the centre outwards to improve the surface finish.
For side grain bowls, cut from the outside toward the centre. Start by removing a small area at the centre and progressively work outwards, maintaining the shape of the hollowed area to match the outside of the bowl.
If you are intending a very thin wall, remove the inside of the bowl to the point where adequate strength and support still remains throughout the bowl to the rim. Then, work in small sections of around an inch at a time, reducing the wall to the desired thickness before proceeding to the next section. Blend the transition between sections before moving on to the next one.
Attempting to turn the whole bowl excessively thin in a single stage will result in uncontrollable oscillation within the bowl wall and it will become almost impossible to take a clean cut. Working progressively as described will maintain support for the section you are cutting.
One final word of caution – once you complete a section and remove the next one, don’t go back for another cut because you have just removed the support!
Back to Shaping the bowl