looking for advise with segmented bowls

[mike falconer]

I been turning for about a year and have constant problems with the out come of my segment rings/bowls. I have a segment jig that works just fine but during glue up I always end up with the smallest (1/32or so)of gaps, and rings not being totally flat. Typically i will try to flatten rings with a quick pass thru the thickness planer or by hand on a isolating belt sander. Neither seem to give me a perfectly flat ring when stacking multiple rings on top of each other. So once i get the bowls roughed out I have little gaps that show up as dark glue spots. does any have any tricks to keep gaps tight when doing segmented bowls? I get my saw and jigs set as close to perfect as i can but in 18 seg rings the smallest off set multiplies into a ugly problem.

[Peter Fabricius]

Mike, if your cutting sled is truly good and your segments are good in dry testing. Glue up your rings 360 degrees with a long hose strap. The kind that you screw down to tighten. Set on wax paper and get as flat as possible. Let cure 24 hours. Use a flat large plate with little centering rings cut in it, about 1/2” apart. Put the segmented ring on the plate while on the lathe, attach with about six dots of hot glue around the edge. Face segmented ring with a round nose negative rake scraper, finish with a 100 grit sanding board. Now reverse the segmented ring to the tailstock and press/glue to the bowl base. This would be for the first segmented ring. The second would be done the same on the centering plate and the first ring would be faced off on the lathe before attaching on the second ring.

[mike falconer]

how long do you wait between gluing and "facing" rings on lathe? ive never seen a bowl assembled on the lathe, but it makes sense as you can true up any imporfections and keep each plane true to the bowls radius.

[Peter Fabricius]

I usually wait overnight for glue to cure but when attaching the rings to the backer plate with hot glue, you only need a few minutes. Last thing in the shop in the evening glue on a new ring to the bowl and go to bed!

[Don Jarvie]

Here’s a few tips from experience. I use 12 segments per ring or 15 degrees for most of my bowls so I made a fixed sled. It’s based on the wedgie sled. For glue up I use a piece of granite with wax paper on top and use the rub method to glue up 2 to 3 pieces at a time. If the segments aren’t right you will see it when you glue up the 2 half’s.

The granite keeps one side flat so you only need to address the other. I just got a drum sander but before I glued up 80 grit on a piece of mdf and rubbed the ring back and forth till flat. PITA but it worked.

For the final glue up I stack one at a time. It takes a while but it works.

[JohnC Lucas]

I do like Don. I built a Wedgie sled after spending many years doing my segments with various other tools and it's hard to beat the sled for accuracy and ease. I have a 2 pieces of MDF glued together with Formica on top that I use instead of the Granite. After I clamp the rings together with glue I use a plastic mallet to tap all the segments down flat against the board. I wax the Formica first so it's easy to clean the glue off afterwords. I flatten one side of the ring either on a disc sander or hot glued to a wooden faceplate. Then I glue that ring to the project and flatten that ring after the glue dries. Patience is the key to making really good segmented projects. I have done segmented work by making all the rings, flattening one side on my wide belt sander, flip them over and do the other side but I've had occasions where there will be a slight convex surface to the rings. If you glue the rings to a board using double stick tape before running them through the thickness sander it prevents this.

[Mark Greenbaum]

Yesterday I had a Youtube marathon, and watched Kyle Toth assemble his 100th segmented vessel. Watch his videos and maybe you see some techniques to help you.

[allan kuntz]

I use the MDF face plate and sanding board. I only clamp my rings for forty minutes weather they are in hose clamps or attached to the piece i am turning.I have never had one come apart. I have been using tite bond3
Al

[Grant Wilkinson]

If you don't mind a couple of questions, I would like to know more about the design of your "segmenting jig" and how you are clamping the segments to form a ring.

[Jed Hefley]

Is the top and bottom of your stock parallel? I ran into this problem once when my planer was out of whack. Or perhaps there I some side movement in your sled/track?

[Don Jarvie]

I made my “Wedgie” sled based on the one online but it’s fixed for 15 degree segments. I got a piece of MDF and attached the runner on the left miter slot and then ripped the sled square. I then used a protractor set to 15 degrees to attach the 2 wedgies so I don’t have to flip the board. As long as the sled is square to the blade the segments will come out to whatever angle you set it at.

I like the sled fixed since it’s more accurate. If the arms move you have room for error.

[mike falconer]

thank you guys for all the tips. i think i will start of with half circles next time around, for the rings then flatten on the lathe. A fixed sled sure sounds like a good idea too.

[mike falconer]

If you don't mind a couple of questions, I would like to know more about the design of your "segmenting jig" and how you are clamping the segments to form a ring.

The sled is a mdf wedgie sled i made and set with digital protractor. i clamp rings with large hose clamps and tap wedges as flat as possible before finial tightening.

[Grant Wilkinson]

I'll yield to the more experienced turners here, but I've done many segmented and open segmented pieces, and use the hose clamps to hold the segments while the glue dries. I've found that it is very easy to pull the ring out of flat by over tightening the clamp. You can tap the individual segments down, but that will not, in my experience, prevent the ring from racking. You can use weights or a bowl press to keep the ring flat and true while you tighten your clamp.;

[George Stratton]

I cut my segments on a sled and the saw blade is checked at exactly 90 degrees. any angle throws everything off. I glue up 3 pieces at a time with titebond 2 by coating both edges and rubbing them together on a piece of waxed paper until they don't move anymore then leave them dry as is. No Clamping. then glue 2 of the 3 piece groups together the same way and after that dries check the edges of the 1/2 circles and touch up on a flat piece of sandpaper. Then glue the 2 halves the same way by rubbing them in while squeezing them together. No clamps needed and usually flat enough to stack or slight touchup on the belt sander. Now you clamp or weight down the layers. They havn't come apart yet while turning!!! Geo.

[tom lucas]

I find a thickness sander does a nicer job getting the rings flat than does a planer. I think the planer flexes the rings more because it can only take so small a bite. I also use a bowl press to glue up the layers. I'm no expert, though. I've only done a few bowls so far, but no gaps.

[JohnC Lucas]

I've tried most of the glue up methods. Ideally you need to get your cutting jig accurately enough to glue the whole ring together at once. Small rings I glue using rubber bands. Larger rings I glue with hose clamps. I have used the half ring method and the rub joint method to glue pairs. The problem with doing that is the ring never comes out perfectly round which isn't a problem for a lot of segmented work. However if you have details that need to align in each ring you will have problems. It's something we all deal with and you have to find your own solutions. I even went so far as to make all of my rings divisible by 4 so I could check the accuracy at 90, and 180 and true it up each time I checked. that helped but nothing is better than getting the segments so they fit and clamp the whole ring. When you start doing 16, 24, and 32 segment rings glueing up in pairs gets even worse and my friend and I think it's simply because the glue joint it self changes thickness. It only needs be off a thousands of an inch. In a 16 segment ring that's 16 thousandths which is a pretty good gap.

[mike falconer]

i was thinking of making 2 sleds one setup for 12 segments and 1 setup for 16. if i was to spend a day just cutting segments and adjusting angle to perfection I would end up with perfect segments every time Right? it'll take some time and burn up some lumber but id think it'll make life easier down the road.

I've been trying to make bowls with segmented accents in them so getting all the segments to align is kinda a must. I know most people don't notice but I sure do.

[Don Jarvie]

2 fixed sleds once set up would give you near perfect segments. Make sure you runner for the miter sled has no play since any wiggle can throw off the segments. Some like the adjustable sleds but it needs to be dead on each time. There’s more room for error in my opinion.