We have several excess Hemlock timbers left over from the
main house construction, some of which were surfaced on all 4 sides
and stored in the basement for the past 3 years. (Most of the rough surfaced Hemlock timbers
have been stored in our shed.) I cut two bowl blanks off with my miter saw,
about 6 inches square and 4 inches thick.
I used a faceplate attached with screws to mount the blanks on the
lathe.
For the first bowl I turned, I
had in mind a dog's bowl, rather rounded inside and out, and thick walled. In the pictures this is the one on the left. The walls of this bowl show a show a
bead-like round shape in the middle of the outside wall with cove cuts on top
and bottom and the lip extends out and is slightly rounded. The walls are 0.5 to 0.75 inches thick and
the bottom of this bowl gradually meets the sides of the bowl with a curve. There were a couple of shallow cracks in the
Hemlock up near the lip of this bowl, so on the second bowl I turned the blank
around and mounted the faceplate on the opposite side from the cracks, putting
them on the bottom side of the bowl and, as it turned out, these cracks were
eliminated when I turned the bowl and fashioned the foot for the bowl.
For the second bowl I was thinking of a more
classic bowl shape. This bowl rises almost straight up from the bottom and
then a cove cut extends the walls outward up to the lip where there are two
shallow cove cuts next to each other with a slightly rounded bead between
them. The interior walls start straight
downward and then bulge inward where the outside of the has the major cove,
somewhat mimicking the shape on both the inside and outside. Wall thickness on this bowl ranges from 0.25
to 0.5 inches, with the thickest area in the bottom of the bowl. Because I mounted these bowls on different
sides of the blanks, the growth rings on the first bowl mostly curve downward,
while the rings on the second bowl mostly curve upward. Both
bowls were finished with a combination of mineral oil and food-safe wax.
Because I started turning these blanks while they were
square shaped, a lot of the initial turning was just to make the square round,
which is slow and tedious work, so next time I will remember to at least cut
off the corners of the square to make a hexagon or octagon, which are much
easier to turn into a round shape. Also,
I am still pretty cautious about the thickness of the bowl sides. Getting the thickness down to 0.25 inches all
around is my goal now. Another issue I
ran into was wood tear-out which makes the surface of the bowl rough and
requires a lot of sanding to hide. Part
of the cause of tear-out is the type of wood--soft wood is more susceptible to
tear-out. Dull tools will also cause
tear-out, as will poor turning technique.
I think all of these were reasons why I had so much tear-out.
I'll have to work on them.
