Making a curved table apron

[Jeff Monson]

I'm working on a demilune table and I'm looking for some help on making the apron for the table, it will be 4" tall and require 3 different bends.
Whats my best approach for this? Using plywood and cutting kerfs in it to accomplish the curves or making a mdf apron and veneer it? I'm using maple as the wood, and havent made anything quite like this before.

[Jamie Buxton]

There are several ways of making curved parts. Which one to use depends on how big the bend is, whether it is seen from the back, and what skills and tools you have.

Sawing. Get a big piece of wood and bandsaw away whatever you don't want.

Bent lamination. Bandsaw stock into laminates thin enough to bend around your sharpest bend. Make a bending form. Slather the laminates with glue, bend over the form, and wait for the glue to dry. Make the laminates wider and longer than you eventually need, because they'll squidge around in the gluing step. Trim the glued-up part to size.

Kerfing. Buy prekerfed material, or make kerfs yourself in the back of some base material. Make curved ribs. Glue the kerfed material to the ribs.

Veneering. Make a curved substrate by sawing or or bent lamination or kerfing. Veneer for show over the substrate.

Me, I like bent lamination. I have the tools and the knowledge to do it. YMMV

[Chris Padilla]

You can steam-bend solid wood as well but I'd go the bent lamination route Jamie suggests. I've seen David Marks do it way too many times and it just looks cool.

[David DeCristoforo]

What Jamie said but there is one other method not on his list that is very "traditional" for this kind of work and that is to "bricklay" the apron out of 5/8" or 3/4" thick stock with any splices staggered. Then you can clad the apron in veneer on both sides creating a "lumber core" which can then be veneered on the face with material of your choice.

[Mike Henderson]

The apron on a table contributes a lot to the strength - it resists racking of the table. For that reason, I don't like to use MDF - it just breaks too easy.

I haven't use all the techniques Jamie notes - in fact the only thing I've used is bent laminations, either of the actual wood facing, or as a backer for veneer. If you go with bent lamination, you need to make a good form, and you probably need to do one test piece to see if you get what you want from the form (the right shape).

I don't like the "sawn from solid stock" technique on a curved table apron because of the way the grain winds up looking. Look at some chair crest rails that are sawn from the solid to get an idea of what the apron would look like. I much prefer the grain flow you get with veneer or bent lamination.

Mike

[Jeff Monson]

Thanks for the good info. the bends on the end of the apron are pretty sharp so I had ruled out lamination, maybe I'm wrong. Can laminations be bent as far as kerfed wood?

[Bob Abbott]

I'd go with the bent lamination. One thing in addition to Jamie's post: After bandsawing thin enough to bend on the form, I run it thru the planer to get a smoother surface between the layers. This can get tricky with highly figured material, sometimes with spectacular results, but by spraying the surface with water before planing the chipout can be minimized. I also will soak the laminates before doing a preliminary bend on the form if the bend is relatively tight. Bent lamination is also easier with flat sawn grain.

[Bob Abbott]

I've done bent laminations down to a 2" to 3" radius, but this requires laminations down to ~1/16 inch which can be a pain to plane. And that need lots of layers to add up to the required thickness. What radius were you considering?

[Paul Girouard]

Yes , futher I'd say , IF its milled thin enought.

http://i21.photobucket.com/albums/b299/PEG688/Jan2820086.jpg

You need to build a good strong bending form and provide clamping points on the form.

http://i21.photobucket.com/albums/b299/PEG688/Feb1220082.jpg

[Doug Shepard]

There are some pretty tight radii on this table that were done with 1/16" laminations. The thicker apron and stretchers were with 1/8". All of them were done with the soaking then pre-bending in the forms before glue-up that Bob mentioned.
http://www.sawmillcreek.org/showthread.php?t=15693

[Rick Thom]

What Jamie said but there is one other method not on his list that is very "traditional" for this kind of work and that is to "bricklay" the apron out of 5/8" or 3/4" thick stock with any splices staggered. Then you can clad the apron in veneer on both sides creating a "lumber core" which can then be veneered on the face with material of your choice.
I used the method David describes.. 3/4" wide mdf stacked up @ 8" high and shop-cut veneer glued on using a tight-fitting form. MDF was chosen because of it's stability. The center section of the apron is a drawer, and made of solid cherry board.. the veneers for the curved end sections are cut from the drawer board so all 3 are grain-matching.

[David DeCristoforo]

"...glued on using a tight-fitting form..."

A vacuum bag is invaluable for this kind of stuff....

[Chip Lindley]

Rather than planing such thin stock and risking tear out, drum sand it! A carrier can be built for sanding 1/16 or even 1/32 veneers without risking the drum too near the coveyor belting.

[Ben Davis]

Rather than planing such thin stock and risking tear out, drum sand it! A carrier can be built for sanding 1/16 or even 1/32 veneers without risking the drum too near the coveyor belting.
you beat me too it! Drum sanding has got to be the way to go with thin laminations 3/32 or 1/16, etc.

[Alex Berkovsky]

Jeff,
My first project was a demilune table. I followed David Marks' plans on DIY network (http://www.diynetwork.com/diy/ww_tables/article/0,,DIY_14446_2275127,00.html). After I resawed the strips for the apron, I had a friend run them through a drum sander for me.

[Frank Drew]

I'm with David in liking bricklaying; it's certainly a proven technique and all those old pieces have shown that it's possible to violate the "veneer both sides" rule when covering a bricklaid assembly, even when using two layer of veneer (the face veneer and a counter veneer underneath to ensure that all those joints don't telegraph through.) Bricklaying also has the advantage over steam bending (and, to a lesser extent, laminating) in being free from springback. A sock-like vacuum bag works well to apply the veneers to the cleaned up and sanded form.

Laminating is a great technique, though, and to save time over resawing you can purchase thick construction veneers fairly cheaply. I'd recommend a slow setting glue that features little to no cold creep, such as Weldwood's Plastic Resin Glue, rather than white or yellow glues.

In general, only very mild curves are structurally suitable for cutting from solid and even then the grain looks a bit funny, as Mike notes.