It starts at the salvage site where a thick hunk of wood is sliced off the log. This piece is 20" diameter and 10"thick. The first step is to find the center and attach a faceplate to the side that will end up hollowed.
The next step is to lift this log of ambrosia maple onto the lathe and screw it on the headstock spindle. Any lumps that will catch when rotated are trimmed off with a drawknife and the lathe turned on at a slow speed while initially rounding.
After rounding the outside curve is established and a tenon is cut to allow clamping in a chuck. The turning is then reversed with the faceplate held by the the revolving center in the tailstock for added support as the piece is still quite heavy. the inside is hollowed leaving the column in the center for support.
After the inside is hollowed the center column is turned off and the center of the inside is refined. The bowl is then removed and filled with denatured alcohol for twenty four hours to remove moisture which might cause the wood to crack while drying.
After the soak, the bowl is wrapped in brown bag paper to slow down the evaporation of the remaining moisture. The difference in the drying rate between the surface and the interior causes different shrinkage rates in wood and that causes cracks.
After about a month for a one inch thick wall the wood is ready to mount and turn again. The wood shrinks less along the grain than it does across the grain the bowl will not be round. This bowl was turned end grain so that is less of a problem. The brown stain at the rim is from tannins dissolved in the alcohol. The white part had been re-turned.
The end view of the bowl before the finish is applied. The small crack in the center sealed up when the finish was applied.
The finish is a coat of Danish oil wiped on then dried for a week, lightly sanded then repeated at least three times. The bowl is then buffed with tripoli abrasive followed by buffing with a polishing agent then a final buffing with carnauba wax.
A final coat of microcrystalline wax helps resist finger prints.
Time from picking up the log in the recycle yard to final finish is about three months. Learning to do this takes at least a couple of years.
A'Tuin the wooden turtle holds the world on his back.