Turning the inside of a segmented vessel

rtaylor

PRO Member
Probably A very stupid question. Is it OK to smooth the inside of the vessel as you are building up? It seems that once you get to far into the ring build up it is very difficult to achieve a smooth cut because of the depth and the opening is getting smaller. I do understand you must keep the strength integrety especially in the first few rings. If you are just cutting off the overlap, so to speak, as you go up it does not seem like it would loose any strength. Can you make the cut the final smoothing cut in the bottom half at least so that you don't have to go back and do anything by the time you reach the top?
 
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Dick Sowa

Guest
That's an excellent question, and one that I agonized over for quite awhile. What I came up with works well...at least for me. My normal practice is to turn the tips (inside and out) off with each ring. Essentially making the ring round. But that is as far as I go till I get farther in the assembly. That leaves plenty of meat in the vessel.

On smaller vessels, I usually don't touch the inside except for the rounding, until the outside is profiled like I want. Then I turn the inside just as if it were a solid wood vessel...hollowing to the wall thickness I prefer.

On larger vessels...say ones that are a foot tall or more...I will make them in several sections. The maximum depth per section is about 6". So for a vessel 18" tall, I will make it in three sections, hollowing each section, and then gluing the assembly together.

The only problem with that approach is that no matter how careful I am with each section, there will always be a slight bit of difference in diameter and wall thickness. I solve it by a very light touch on the inside to smooth the seam, and a final cleanup of the outside ... shear scraping so very little stock is being removed, but the joint gets cleaned up. If I do it right (which isn't always the case), it is impossible to tell where the seam is.
 

rtaylor

PRO Member
Thanks for your tips Dick. When you work in sections on larger vessels how do you mount them without a faceplate or chuck block? I'm sure I'm just missing something here.
 
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Dick Sowa

Guest
Although there may be other ways, I treat the bottom of the vessel as the "base" that never comes off a faceplate, until the entire vessel is finished, and I reverse mount it with either a doughnut chuck or a jamb chuck to finish the bottom. I also use a bowl steady at that point to make sure it doesn't go flying.

Other sections are also treated like individual bowls. The bottom ring in a section starts out by being glued to a waste block attached to a faceplate. Then when that section is completed, I part it off of the waste block, reverse it in a jamb chuck, and finish off the bottom of the section. When that section is done, I put the base section back on the lathe, and using my tailstock as a centering device, glue the new section to the base section.

Bottom line, with my technique, it requires you have several faceplates with waste blocks available.
 

rtaylor

PRO Member
OK that makes sense to me. Thanks for your help. I thought about doing something like that but I didn't know if others used that technique or not. I am self learning about segment turning. This site is helping me a lot.
 

Art Bodwell

PRO Member
I take a different approach. I start with a drawing of my vessel to full scale. Depending on the size and shape of the finish vessel I will add 3-5 rings from the base and shape the inside to the final dimension, except for the top 1 or 2. I leave these slighly over size so I can blend them to the next group. I then add another 3-5 rings and do the same thing, continuing until a reach the top. Then I have a finished inside and then move to shaping the outside all at once usually with a cone on the tail stock inserted into the top to eliminate vibration. This of course assumes an open top vessel. If I'm doing a vase, urn or something with a small top opening, I will do them in two halfs and join the halfs. Just another way that works for me.
 
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