It is a nice looking bowl. However I would worry about wood movement problems. Depending on the species this may or may not be a problem. However the pie shaped segments will move in a different direction than the rest of the bowl when moisture makes it expand and contract. Depends a great deal on the size of the bowl and species as to whether this will happen or not.
I turned 4 clocks about 3 years ago with the pie shaped segments glued into a solid ring in the middle. I wanted to see what would happen. 2 of the 4 developed a crack and this was using mahagony and maple. Mahagony is fairly stable but maple moves a little. Still not totally sure why only 2 cracked and 2 stayed good.
i know good wood workers never tell their mistakes but I don't consider myself good. This is only the 8th bowl I have made. The sides of this bowl are Elm and the bottom is White Oak. The Elm was a 5x5x3 solid block. When I turned it I made the bottom of the bowl to thing and when I parted it off the waste block the parting tool went through the bottom. I cut off the broken bottom and made the segmented Oak bottom. When I glued together all of the segments the points did not meet properly in the center and left a small hole. I drilled out the center with a hole saw and turned a plug from Oak to fill in the center.
I fully understand about wood movement and by no means am I taking your comments in a negative way. You have been nothing but helpful to myself and many others, but right now I am just concerned about making a nice looking project. If it does move and split I will consider it a learning experience and cross that bridge when I get to it.
I had also read in an old issue of "Wood" magazine 2 ways to help stabilize wood movement in a segmented disk. One was to glue up the segments in a half circle. Dry fit both half circles and us a "biscut" that is used in furniture making in the center where all the "pies" come together. The 2nd way was to use a router to cut out a circle half the thickness of the segmented disk and make a plug to glue into this circle. This method you are gluing side grain to side grain. Since I made a mistake and I don't have a router, this is where I got the idea to plug the center. Since I am gluing end grain to end grain I don't know that this will be strong enough to help stop any movement or not.
Not sure about the 2 methods mentioned in wood magazine. And I've been there and done exactly what you did. Sometimes saving a piece is half the fun and I learn from each piece, successful or not.
To make this method work you need to make a sort of floating ring. The pie shaped segments will expand and contract. Set them in a rabbit in the outside solid wood and leave a small gap for the segmented ring to move into. You can glue it with a flexible adhesive.
For the center ring you can do the same thing. Another option would be to make segmented pie ring out of 2 layers that overlap each other so glue joints overlap like bricks. This gives a lot of side grain to side grain glue strenght.
If you make the bottom hole filler out of homemade plywood it won't move. What I do is to cut up the wood I'm going to use into thin slices. Then I laminate these together alternating the grain like plywood. When this is dry turn it to fit the inner ring. This ring won't move and if you glue up the pie ring with overlapping segments they won't move as much and you might be able to get buy with it.
Thank you so much for that information!!!!!!! I understand that wood moves with weather change and moisture, I can see it in my house with some of my doors and moulding, my problem which is confusing to me is which woods move more then others and which ones are more compatible with each other.
Thank you!!!! This was my 4th try with segmentation. I find segmented work not to be hard but tedious, time consuming and requires patience and precise cuts. I use a miter saw to cut my segments. I bit the bullet and invested in a Forrest Chop Master blade and let me tell you that made a MAJOR difference in accuracy and smoothness of the cut.
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