# Segmented Turning Tools



## BigJoe16 (Feb 20, 2012)

I have been turning more and more segmented pieces and have had a few chips starting at the joints between pieces. I use my scrapers to turn the whole thing and have had fairly good luck with it.
So what do you guys use to turn segmented things. Is this normal ?


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## Dave Paine (May 30, 2012)

Same as for normal bowls, and of my bowl tools depending on what feels to work :
bowl gouge, Sorby Hollow Master, Hunter Hercules, RusDemka round carbide recently added, but not yet used on a bowl.

I finished with a round nose scraper. Also used if I need to remove ridges.

If the segmented pieces are a tight fit, they should not chip. Lots of variables though. Wood species, grain direction, rotation speed, whether the scraper had a fresh burr.


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## john lucas (Sep 18, 2007)

I use gouges 99% of the time. I do have lots of scrapers but usually use them for shear scraping. I do have a bunch of Hunter tools but I use them primarily as bevel rubbing tools and they cut extremely clean. 
Scrapers used flat are prone to that kind of chip out.


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## BigJoe16 (Feb 20, 2012)

Thanks for replying guys. I have a couple more questions. 
If you were to make a segmented bowl, how do you prefer to make the bottom. Do you use a solid piece of wood and have the end grain showing? Or do you cut the bottom to fit in side the bottom ring? What do you do?

And another question. Kind of a stupid one but anyway. If wood expands and contracts to different temperatures, can you acclimate your stock for rings to a colder temp. and cut and glue at that temp., say in your garage, then bring the wood inside to the warmth, would any gaps In The glue joints fill in and tighten up as the wood expands? What would happen? 
Thanks!


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## john lucas (Sep 18, 2007)

Well ideally you should let your work acclimate in the environment it is going to be displayed. Yea I know it's impossible, at least for me. It will move when you bring it inside. So you need to read up as much as you can on wood movement and try to understand how to prevent disaster. 
Moving wood inside will not close gaps. There shouldn't be any gaps. There are lots of ways to achieve perfect gap free rings so that should be your goal. I highly, and I mean Highly recommend Malcolm Tibbets books or Videos. They will answer most questions you will ever ask about segmented woodturning and he does it clearly. 




 You can also join the Segmented woodturners and be able to ask questions from people much more knowledgeable than me.
http://www.segmentedwoodturners.org/
In regards to the bottom it depends a lot on the size and species. Solid wood will move differently than segmented rings. Segmented rings depending on how you build them will not move much. Solid wood moves differently in different directions depending on the grain orientation. For hollow forms that usually have a small bottom I just glue the wood on. Usually I start with a scrap of wood screwed to a faceplate and then glue the bottom onto this. 
For larger bottoms such as my old bowls that had a bottom about 5" and were 3" tall is used to use solid wood. I got lucky and some survived. Don't know about the others. I did make a sort of rabbit joint that gave more glue surface but I didn't allow for the wood movement and I'm amazed they did survive. What I do now for larger bottoms is to make my own plywood. I cut and plane wood down to 1/8" thick or so (it can be thicker if you have enough layers). Then I orient them with the grain running 90 degrees to each other and glue them up. With this orientation the bottom won't move and matches the sides. 
The plywood construction is especially important if you want Pie shaped segments in the bottom. I have had 2 of those blow up. Pie shaped segments with the grain running sort of in a ring around the piece is just inviting disaster. For these I make the top and bottom layer pie shaped and the layers in between are just flat with the grain oriented 90 degrees to each other. My test piece that gets hauled to demos and stays in the house is now almost 12 years old and still holding together.


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## Dave Paine (May 30, 2012)

I have done only one segmented bowl so far, but I will be making others.

I made the bottom from two pieces of walnut and had this show like the other rings. I was happy with the outcome.

Since this was my first bowl I was very conservative on the wall thickness.

Sent this onto my sister as a salad bowl. She said she liked it. Not sure if it has been used though.

http://www.woodworkingtalk.com/f13/my-first-segmented-bowl-40860/

OldMacNut had a segmented bowl explode so you do need to have a good joint between the bottom and the side of the bowl.

http://www.woodworkingtalk.com/f6/sounded-like-shotgun-blast-45212/

As John said, if you want to hide the bottom, good idea to have a groove in the sides to hold the bottom.


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## WillemJM (Aug 18, 2011)

If one keeps the bowl walls thin, it is more forgiving for the base moving across the grain. For anything larger than a 5" dia solid base, I use a floating base. This is done by turning a rabbet in the first ring, with a diameter slightly larger than the base, normally I leave a gap between 1/16" to 1/8" depending on how big the bowl is. The base is then glued into the rabbet, with glue touching only two opposed segments, same grain direction. 
The solid board in the bowl is now free to shrink and expand, without placing any stress on the piece.
In a lot of cases if a solid base is not free to move, it will not crack, however the base will distort slightly as it expands or contracts, meaning it is no longer flat, or in other words the bowl will rock slightly on its base.
Example of a bowl with a floating base:










Example of a inlayed base being glued into a ring with rabbet.


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## SGalley (May 12, 2013)

I did a couple in my shed this winter and put them inside after I finished them. They feel rough now. Ill probably put them back on the lathe soon and smooth them out. No problems with the joints just the segments expanding outward


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