Segmenting Question

[Ted Prinz]

Hi. First real post. Be nice.

I've been turning a while (years) but never did any segmenting. One of my quarantine objectives was to learn it. So I built a wedgie sled and got started. Now I'm hooked on another thing!

Couple examples:



Anyhow - I've not been satisfied with a solid base so I experimented with a segmented base. Liked the results - but they are CRACKING! Research tells me this isn't unusual (seasonal movement).

I'd like to get some input on what (if anything) works. I've been toying with a couple ideas and would appreciate your input.

Thanks in advance!

 

[Gary Beasley]

Look into floating bases as an alternative.

 

[Ted Prinz]

Look into floating bases as an alternative.

Gary - Actually that was an option I was considering. I thought I could route a groove in the segmenting stock, cut the segments and then insert the "base" in the groove during glue up. Is that what you were referencing?

 

[Russ Braun]

That is one way you could do it Ted. I usually cut a rabbet in the bottom ring, insert the floating base, carefully glue the next ring over the top. I prefer complete segmentation on pieces as opposed to solid bases. Guys like Pete Marken do amazing vessels with solid wood bases; it’s just an option. Cracking absolutely sucks!!

 

[Doug Freeman]

I always used segmented bases and did not have a cracking problem. I always left a small hole, 1/4” or so, in the center, then drilled it out to ~ 5/8”. Did this for 2 reasons - 1) impossible to get the segment ends to line up perfect in the middle, 2) I used a ring press with allthread up through the center, so I had to have a hole anyway. Plugged with a dowel before turning.

 

[Don Wattenhofer]

Anyhow - I've not been satisfied with a solid base so I experimented with a segmented base. Liked the results - but they are CRACKING! Research tells me this isn't unusual (seasonal movement).

I agree solid bases don't fit into the design, they really look out of place especially when they flair out.
The method I have been experimenting with is to make the bottom 2 rings with as small an opening in the middle as possible, then with the piece mounted from the other end clean up the hole and taper it. The tapered hole is then plugged with a matching taper end grain plug. The tapered plug will not push the glue out when inserted into the hole but rather will compress the glue similar to clamping. The tapered plug works well for layer segmented or stave segmented pieces.
The cremation urn in my avatar has a tapered plug in the base and the finial in the lid is also a tapered fit.

 

[GRJensen]

I cut a slot for my floating bases on the table saw. I built a jig that straddles the fence and has a speed clamp on the blade side. I clamp each segment (individually) onto the jig and make a pass through the saw. I made a set of back boards for the jig to accommodate the most common segment angles I cut.

 

[Larry Copas]

Floating bottom, several designs and ways to make them. I do this one because its fast and easy.

 

[john lucas]

I do it differently. I make my segmented base. Then I resaw thin slices off of this. I glue these to a piece of high-quality plywood. It now has a segmented slice on both sides so it looks like a solid glued-up piece but it's stable and won't move.
I just started a test piece. I glued up a 24 segmented pie that in my experience will self-destruct in a few years. I resawed it in half and glued it back together with the glue joints offset. We will see if this holds up. I made a hand mirror out of it. I'm moving it periodically from my high moisture basement to the dry house to purposely create a lot of wood movement.

 

[Ted Prinz]

I cut a slot for my floating bases on the table saw. I built a jig that straddles the fence and has a speed clamp on the blade side. I clamp each segment (individually) onto the jig and make a pass through the saw. I made a set of back boards for the jig to accommodate the most common segment angles I cut.
View attachment 37601 View attachment 37602

Gerald - Yep, that's what I'm thinking of. Thanks for the info. (by the way, nice glue cup and brush holder! Gotta steal that idea!). Larry's solution (I think) looks to be cutting the slot before cutting the segments. Have you tried that?

 

[Ted Prinz]

Floating bottom, several designs and ways to make them. I do this one because its fast and easy.
View attachment 37605 View attachment 37606

Larry - Yep, that's what I/m thinking of. Thanks for the info. Based on what I see, I'm guessing you do the "slot" BEFORE you cut the segments which is different than Gerald's solution (above). I'm thinking to try it this way. Have you tried that?

 

[john lucas]

If you use the segeasy to cut your segments.tha same side of the board will always be to the inside and same side up so it would be very easy to cut the slot before cutting g the segments.

 

[GRJensen]

If you use the segeasy to cut your segments.tha same side of the board will always be to the inside and same side up so it would be very easy to cut the slot before cutting g the segments.

I have tried it this way. Actually, you have to increase the width of your stock by the depth you want your groove and plow a groove on both edges of the board, then cut your segments.

 

[Larry Copas]

I cut the slot in the two glued up half rings by using a bearing guided slot cutting router bit in the router table.

 

[GRJensen]

I cut the slot in the two glued up half rings by using a bearing guided slot cutting router bit in the router table.

I did it that way several times ... until the router grabbed the half ring, flung it back at me, and mangled both thumbs and a couple of fingers on my right hand. I was using a small parts holder, but must not have had a tight enough grip.

 

[Don Wattenhofer]

I always used segmented bases and did not have a cracking problem. I always left a small hole, 1/4” or so, in the center, then drilled it out to ~ 5/8”. Did this for 2 reasons - 1) impossible to get the segment ends to line up perfect in the middle, 2) I used a ring press with allthread up through the center, so I had to have a hole anyway. Plugged with a dowel before turning.

I too have never had cracking problems, however I would suggest tapering the hole and making a tapered plug which will give you a much better fit then a straight dowel that may not even be a true round.

I cut the slot in the two glued up half rings by using a bearing guided slot cutting router bit in the router table.

I am thinking that if you value your fingers in their original form that your method would require some sort of jig to firmly grip the half ring while protecting said fingers, therefore it is not "fast and easy".

 

[Don Wattenhofer]

I did it that way several times ... until the router grabbed the half ring, flung it back at me, and mangled both thumbs and a couple of fingers on my right hand. I was using a small parts holder, but must not have had a tight enough grip.

That is what I figured would be likely to happen unless a custom jig were made to grip the entire half ring.

 

[Gary Beasley]

I cut a rabbet in the first ring while on the lathe and set the disc in, then glue a ring on top of that to trap it. I made the disc thick enough I could cut into it while turning the inside of the ring.

 

[John King]

Check out Woodturning Fundamentals, Sept 2014, vol 3, issue 5, p 2, "Segmented Turning, Segmenting 101." Andy Chen shows how to assemble a four piece bottom where the points of the segments meet in the center with no gap. Give it a try. - John

PS - I have not had much luck with floating bottom. Hard to maintain the "float" when assembling the ring stack and applying the finish. While careful glue management to avoid securing the floating bottom to the ring stack is possible, it is virtually impossible to keep the finish of choice from seeping into the void between the vessel and the floating bottom. So, floating bottom no longer is floating. So, I gave up and went back to solid bottoms or bottoms like that shown in Andy Chen's article referenced above. - J

 

[BobCoates]

I looked at Andy Chen's method, John. have you been using his method without cracking or separation of seams?
Also are those using the floating bottoms only for display items. I am thinking like John said about finish seeping in, wouldn't oils or food get in the edge of the "float"? At least that is why I have been using solid bottoms on the bowls that I have made.

 

[Charles Chaloupka]

I use Earls method from Earls small segment shop on YouTube. Everything is done on the lathe and it is very simplistic. Spoiler alert, Earl places two small pieces of tape over the area of end grain on both sides of the piece, then finishes the piece that will be the floater with shellac and finally wax, careful not to get any were the tape is. The finish and wax prevents any future finishing from adhering the float piece. He then applies glue to the two spots where the tape was. Earl provides a very detailed demo on the entire process. Check him out

 

[Don Wattenhofer]

Check out Woodturning Fundamentals, Sept 2014, vol 3, issue 5, p 2, "Segmented Turning, Segmenting 101." Andy Chen shows how to assemble a four piece bottom where the points of the segments meet in the center with no gap. Give it a try. - John

PS - I have not had much luck with floating bottom. Hard to maintain the "float" when assembling the ring stack and applying the finish. While careful glue management to avoid securing the floating bottom to the ring stack is possible, it is virtually impossible to keep the finish of choice from seeping into the void between the vessel and the floating bottom. So, floating bottom no longer is floating. So, I gave up and went back to solid bottoms or bottoms like that shown in Andy Chen's article referenced above. - J

I just looked at "segmenting 101" and see that it is the same as TP's bowl without the accent strips forming a cross. The problem with that method is that the seasonal movement will cause either an increase or decrease in width across the grain where an increase will open up the outer end of the joint or decrease will open up toward the center of the joint. The method might work if the glue up was split into 2 pieces then re glued with the joints straddled.

 

[John King]

I just looked at "segmenting 101" and see that it is the same as TP's bowl without the accent strips forming a cross. The problem with that method is that the seasonal movement will cause either an increase or decrease in width across the grain where an increase will open up the outer end of the joint or decrease will open up toward the center of the joint. The method might work if the glue up was split into 2 pieces then re glued with the joints straddled.

Don - Are you speaking from experience using the "Segmenting 101" method for assembling a base or just expressing an opinion? - John

 

[John King]

Hi. First real post. Be nice.

I've been turning a while (years) but never did any segmenting. One of my quarantine objectives was to learn it. So I built a wedgie sled and got started. Now I'm hooked on another thing!

Couple examples:
View attachment 37595
View attachment 37596

Anyhow - I've not been satisfied with a solid base so I experimented with a segmented base. Liked the results - but they are CRACKING! Research tells me this isn't unusual (seasonal movement).

I'd like to get some input on what (if anything) works. I've been toying with a couple ideas and would appreciate your input.

Thanks in advance!

Ted - If you have not already done so, check out the Segmented Woodturners site at http://segmentedwoodturners.org/forums/index.php. Lots of friendly folks willing to share what they know about segmented turning. - John

 

[Don Wattenhofer]

Don - Are you speaking from experience using the "Segmenting 101" method for assembling a base or just expressing an opinion? - John

The first experience is from many years ago making a table top about 15" diameter out of maple with that same 4 piece grain orientation. The bottom of a bowl would of course be much smaller than my table top and therefore less likely for the joints to open up. The problem can can occur in any amount of segments if the glued up ring sits through a seasonal change without being laminated