With the second layer glued in place and the clamps removed it’s back to the lath to turn the corners off and make the layer
round. The left photo below is before I
started turning and the one on the right is after I have turned the blank
round.
I centered the 2-ring bowl blank on the next layer,
marked the centering circle and the orientation lines as before. Here if you look close in the center you can
see one of the orientation lines marked with an “A”. With the blank still in place I clamped the
alignment blocks where they go.
Below is after the bowl blank was removed. This makes it a little easier to see the
centering circle, where blocks are and how the bowl blank will drop in
place. Next is to add glue, drop the
bowl blank in place, rotate it back and forth to spread the glue then make sure
the orientation lines are in alignment, put the clamps on and finally check to
make sure the layers are still in proper alignment.
The photo below shows how I have several rings in various
stages of completion. In the back is the
rough-cut walnut and cherry strips for ring #7 setting to see if they are
stable. In the front left is a row of
cherry and a row of walnut segments for ring #6 ready to glue together
tomorrow. At the left setting on the
yellow pyramids with the metal clamp is the ring #5 that I glued together
today. To its right is ring #4 that I
flattened today and will glue on tomorrow and finally at the right is the bowl
blank with ring #3 that I just got done gluing on.
The next day after taking the clamps off I mounted the
bowl blank on the lathe and turned the ring round. The left photo shows that done. Now with three rings glued on I can start to
do some turning on the bowl’s inside. On
the right the bottom of the bowl is pretty well done and the second ring is
roughed out. There is a lot of
refinement yet to be done especially at the transition between the bottom and
the 2nd ring. The top ring just has the
inner face rounded and a small radius cut on the inner edge. Lots left to do here but that will wait until
I get more rings on.
I am not going to go through all the steps in making the
rings and gluing them on since that has already been covered. If anything that I have not covered comes up
I will go over it but, in the meantime, here is where I added the 4th and 5th
rings.
Making progress albeit slowly. Here on the left is the 6th ring added and
set up ready to round the outside edges.
The right image shows the 7th ring in place and the inside shaping
in-progress. The bottom layers are
pretty much done while the outer three or four rings are still a work in
progress. The closer I get to the last
ring added the less finished the piece is.
This is the 8th ring glued and clamped in place. It marks the half-way point only 8 more rings
to go. If you look close at the bottom
ring you can see the step between it and the layer above is getting
smaller. That is starting to cause me
some problems in that I don’t have very much room to clamp the centering
alignment blocks on. It’s only going to
get worse as the step continues to get smaller.
The left image has the 8th ring on with the outside rim
rounded while the right image shows the 9th ring after rounding the outside rim
and doing some interior tuning. The pile
of shavings is the result of interior turning and just sits there sliding along
the bowl surface as I turn.
As I talked about when gluing the 8th ring on I was
running out of room to clamp the centering alignment blocks on. Well the left image is the 9th ring with blocks
barely attached and the right is the 10th ring.
As you can see there is no way I can clamp the blocks on this ring. That means that I will use a rub joint to
help get an initial “tack” to reduce the piece slipping around as I clamp them
up. A rub joint is where you slide or
rub the two surfaces back and forth until the glue becomes tacky and grabs. It makes it easier to keep things aligned as
the piece is clamped.
Here is the 11th ring.
This ring represents the largest diameter of the bowl. From here on in the rings will get
smaller.
The left photo is with the 12th ring in place. It is just a bit smaller than the previous
ring and that’s because I am working my way down toward the opening at the
top. Because the interior surface of the
bowl is curving back I am having to get into some contortions to do the
turning. All along I have been finishing
turning on the inside. Now the interior
surface is about 95% done up through the 8th ring and 90% done through the 11th
ring while the 12th ring is about half done.
The right photo shows just how tall the stack has become. There is right at 12” between the faceplate
and the outer face of the 12th ring.
Unfortunately, as I was working on this ring I started getting some
vibration and minor chattering while turning.
Changing the RPM’s, using a light touch and sharpening the tools helped
but this means that I have gone as far as I want adding rings using this
setup. There are a couple of techniques
that I could use to steady the bowl and dampen the vibration but I would still
have the awkward turning position. Then
there is the problem of weight, as it sets including the cast iron face plate
the blank is pushing 50 pounds. Holding
it up at the lathe in proper alignment with one hand while using the other to
start the spindle threading into the face plate is getting pretty close to
making my eyes bug out. To resolve all
these problems, I will turn the remaining four layers separately then marry the
two halves together. In retrospect I probably should have made the split between the 11th and 12th rings right at the widest point.
Next up – Adding Rings & Fitting the Halves
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