Gluing Up a Round Table Apron
Furniture-makers supply tips and techniques for a large circular lamination. October 2, 2005
I am bidding on a conference table with continuous apron. I will lam it up with 1/8" x 3" x 60-80" walnut, but am at a bit of a loss about sequence of lay up. Main concern is that 8 or so plys laid up with that much length will leave too much slack as stack built up, making nasty gaps, bubbles, etc.
Will likely lam up two sections (there would have been at least two seams even if apron was lammed up as one) of about 190 degrees each and join with splines and a scab behind joint. Any comments most welcome.
(Furniture Making Forum)
I made quite a few one piece, full circle laminated aprons for a small cigarette table design. These tables were about 20" diameter. I am sure I would never attempt anything like that with your size of table. I remember it being difficult to get the lengths of the laminates correct because it was difficult to calculate the thickness of the glue. But I finally got it worked out and glued them up. If you build your forms correctly and accurately and you have enough clamps, you won't get any bubbles or gaps. I am not sure what you mean by sequence in lay up, but I would use a glue with enough open time and glue up all the plys per section at once.
From the original questioner:
Thanks. I've done a lot of millwork - door and window arches - all with PVA glue, but will try something recommended for longer open times and thin applications. Great comments on the thicknesses, which I had not considered.
Unibond 800 is made for this type of work Long open time, will cure in a bag, and is brittle (no creep). The vacuum press/veneer fellow, Daryl Keil?, in Maine carries it, at about $17 per half gallon. Put the leftovers in the beer cooler, and the shelf life is excellent.
Any shape is possible with L-shaped ply brackets, I learned. We screwed them on the underside of the table temporarily to the inside line of the apron and then dry-assembled with an inside pine strip, a half inch pine kerfed strip and then the show wood. The inside and outside strips were joined on a 45 degree for some play. Spring clamps onto the brackets were used at glue-up and then a band cramp. Removed later, the apron was put round the planer and the brackets all removed from table underside. We used urea glue on slow! A beaded strip was added then to the bottom edge and run round the spindle.
If you're really worried, I'd just glue up the core first, let it cure, touch it up, then laminate the last layer. This way, you can get the joints tight where they show the most. Another trick is to allow for extra layers of material "cross cut plywood" on both sides to act as clamping culls. This will give you a smoother, less bumpy glue-up.
From the original questioner:
Thanks all - really great suggestions and comments. Client now is "thinking about" a leaf with a slider...