>Most segmented turners I know don't clamp their segments, they rub the surfaces together, and set aside to dry.
I clamp everything, two pieces at a time as I build the blank. It may seem like a waste of time, but the results are worth it, in my opinion.
I usually have three projects, all at different stages. as the glue dries on one piece, I may be hollowing another. That way there is no down-time waiting for glue to dry.
I posted a detail of a finished piece....the glue-line on the yellow-heart is nearly invisible.
>I can certainly vouch for Keith's superior glue joints having seen several of his pieces up close. He also did a great presentation at our woodworking club last week and really impressed everyone with the high quality of his work. And he makes it look so EASY! He even went so far as to tell us that everything he does can be broken down to basic woodworking techniques. Looking at his work does he really expect us to BELIEVE that? Actually it's entirely true when you see how he glues and cuts his segments. Even John Jordan and Binh Pho commented on his great glue joints at our Symposium last fall. They actually raved about how perfect they are.
On the subject of Symposia-we are doing it again this fall! Check the events board for more info. Not sure about all the presenters yet but Keith might be one of them.
Keep up the incredible work Keith-can't wait to see what you come up with next!
Thanks for showing the joints of your work. You also stated you clamp 2 segments at a time and then clamp more. Would you mine showing the 2 clamp segments or rings that you have done? The actual clamps. Thanks GT
>Hi George, yes I will post some photos. I don't have a digital camera, so it may take a while.
I think nicely fitting joints in a segmented piece really makes it stand out, especially since there are so many pieces on display.
I may have an unfair advantage, coming from a fine-furniture background, but I enjoy sharing some of my techniques. Perfect joints are expected on high-end furniture, I'm trying to do the same on my turnings.
>Nobody want to hear it, but the truth is that a clamped joint will always be stronger, more stable, and last longer than one that was made by rubbing two sticks together.
Having a problem with that deadly "glue creep"?? Any kind of clamping will make for thinner and more uniform glue-lines, and that directly relates to a more stable glue-line and less creep.
I have learned in the last year or two, never to question your facts, However.... Flat woodworkers clamp the crap out of their work, and they still get glue creap. Explain?
>Bad joints are bad joints, whether they be flat or round.
We will never get rid of glue creep when we use PVA glues, but we can reduce them with thinner glue-lines. A thin glue-line can be made by rubbing them together, but most folks just don't rub enough to work the excess glue out of the joint. Thicker glue-lines equate to greater glue creep.
Bad glue joints are more obvious in a piece of turned wood than they are in furniture because we hold it in our hands and look at it up close and personal. Most of us don't get that close to a table or a chair.
We can solve a lot of the problem with glues that are less elastic than Titebond. Glues like Hide, Plastic Resin, Phenols, etc. will all make more stable joints, but, except for the Hide, they all require clamping.
>I've encountered problems with wood movement, especially when using a solid piece for the bottom of a segmented piece.
The wood moves in a different direction than the rest of the piece, causing a glue-joint failure.
Sometimes I think what appears to be glue creep is actually wood movement. I now make all my pieces with a laminated or segmented bottom.
Flat woodworkers make all kinds of allowances for wood movement; floating panels, mortise and tenon joints with room for expansion, etc. We don't have that luxury, unfortunately.
One of the things I find most challenging in segmented work - is keeping the grain all running (Relatively) the same direction. This is especially difficult in the, so called, design rings. In the "Square Wave" design that I use (maybe too) frequently, in the past the vertical bar used to have the grain running vertically, while the rest of the grain in the ring ran horizontally. Then I noticed, that the lacquer on my pieces with this design was cracking at this joint. I now make this vertical piece differently, so that the grain runs horizontally as well. If you look closely at this photo, in the Yellowheart, you can see the grain. No cracking in this piece.
I think that we are especially challanged in segmented work, in that normally we are using several different species of wood, all with different movement properties, all in the same piece.
>Mark, I think you solved the problem on that piece. The grain is no longer fighting against itself. I have learned (usually the hard way)not to attempt to "box in" a piece of wood. If the glue joint doesn't fail, the wood usually cracks.
Usually you can plan on grain orientation in advance. What you described in your pieces is what some mistakenly refer to as glue creep; in reality it was wood movement.
You took a design problem and solved it, I would say. pretty piece!
