Originally posted 11 November 2013
Once we have a log all cut up we need to rough turn and seal the bowls. We start by cutting them round on the band saw. This step is not entirely necessary, but it makes rounding the blank on the lathe much easier.
I have a number of rounds cut out of thin particle board and plywood. I can set a round on a bowl blank that has been cut out of a log and get an idea of the size of a bowl that I can get out of that log.
Once I have selected the round pattern piece, I screw or nail it to the bark side of the wood and use it as a guide to cut the blank round on the bandsaw.
I have rounds from 6 inches up to 15 inches.
Once i got the blank rounded I can mount it on the lathe.
I’m mounting this one between centers. I sometimes use a “woodworm” screw, which makes my lathe chuck into a screw chuck.
I start rounding the blank from the back.
The object is get a tenon turned on the back so I can turn it around and get it mounted in the chuck which is a more secure way of holding it.
Here is a close up view of the tenon turned on the back of the bowl blank.
The tenon has a deliberate dovetail shape on it that helps to hold it securely into the chuck, The chuck has a matching dovetail machined into it.
At this point, I am ony roughly shaping the bowl blank so that it can dry down for final turning some time in the future.
We turn the blank around and mount it in the chuck.
For the first part we use the live center to support the flat side of the bowl blank.
Remember that dovetail shaped tenon we put on the other side of the bowl blank? Here is the tenon securely gripped in the chuck.
We are looking here to see that our 15-inch bowl blank has “cleaned up” to about 13 inches.
This bowl is deep enough that we can core it out to get another bowl blank from the inside of the bowl. This has an added advantage of creating fewer wood chips to clean up.
The coring tool is a curved knife that cuts down into the bowl blank.
After we core the bowl and clean up the remainder of the wood a little, we seal the end grain on the bowl blank with a wax emulsion.
We seal the end grain of all the complete bowl blanks and the other pieces of the wood. The sealant helps to keep the wood from cracking. After the initial drying period for the sealant, we will set it on a shelf in the back barn. Once the bowl is rough turned, it takes three to six months for it to dry down to where it can be final turned.