When I was doing the final turning on the bottom of the
bowls after the sacrificial base had been removed from the maple and cherry
bowls using the jumbo set of jaws the process went pretty well except for a
couple times. In one case the bowl came party loose and the other time it popped
completely out of the large jaws.
Fortunately for me the bowl that came out of the chuck still had the
base on and it landed on a big pile of wood shavings which cushioned the
impact. Only damage was a couple of
scratches that could be sanded out but I did have to swap the jaws to remount
the piece so I could sand it. When the
bowl flew off, I knew I needed a little something to help hold the bowl in the jaws. My solution for this was to make
an attachment that puts a little pressure on the base. It consisted of a wood turning that screws
onto my live center and has the last inch or so of a pencil along with its eraser
inserted into a hole in its end. The
left photo shows the piece and pencil stub that gets inserted into it while the
right photo shows the completed assembly. 
In use the bowl gets mounted in the jumbo jaws and the above
assembly gets screwed onto the live center. The tail stock is then set to apply a little
pressure to the base which helps keep the bowl from coming loose and go flying
across the room which is a lot less stressful for me. The pencil eraser acts as a flexible
non-marring cushion against the base of the bowl.
Once the turning of the base is completed and sanded the
walnut and oak bowls are ready to be sprayed with lacquer.
Before starting the finishing of these bowls, the lathe
turnings from the last six bowls get swept together and it’s a pretty good pile
pretty much the same size pile as the first group of six. Out of curiosity when I had the turning
blocks assembled and before any work was done on them, I had put the large
bowl’s walnut and oak turning blanks on the digital kitchen scale to see how
much they weighed. My plan was to weigh
them again when completed to see how much material got made into shavings. Both of the blocks were within a couple of
ounces of each other at about 2½ pounds each with the oak being a couple ounces
heavier. When finished the large walnut
bowl weighed 4½ ounces and oak one weighed 5¾ ounces. That means that for each large bowl a little
over two pounds out of each blank or roughly 85% of the blank was converted
into shavings hence the pile you see in the photo.
The maple and cherry bowls here have three coats of
lacquer while the oak and walnut ones only have one coat so far. A few more days of spraying the rest of the
coats on and they will be done.
My process is to spray the inside of half of the bowls
and on the other half spray the outside in the morning. They are then left to cure until the
afternoon when they are reversed and sprayed so each day both the outside and
inside get a coat of finish. They are
then left to sit overnight and wet sanded the next morning with a 1,500 grit
pad, left to dry for an hour then the process is repeated. One difference with the last coat is to let
is set for a week so to allow the lacquer to really harden before lightly wet
sanding using a 3,600 grit pad to just remove any dust particles. When done, here is what all four sets of bowls
look like.
For storage the bowls are designed to nest within each
other like this.
This has been an interesting project with all the different design options being explored and tested to see how they looked. In addition, the proportions had to match across all twelve bowls as well as having all the same size bowls match between the different sets. To make this happen I needed to come up with a repeatable process for the turning sequence which I don’t usually have to do. While I enjoyed the challenges and am happy with the results, I am pretty sure one set of these is all there is going to be. 😊
No comments:
Post a Comment