Woods that bend?

[Duncan Potter]

I want to build a table with curved legs, laminated from multiple plys. I expect the legs to need to be about 3/8 x 2 x length (30" or so).

My preliminary thinking is that I might want to glue up the legs from 3 or more plys on a form, sandwiching a contrasting wood in the center

This will be another first time iteration for me so

1: Any general pointers on the technique

2: Glue type? Titebond? Resorcinol? Epoxy?

2: Any woods that are particularly good or bad for this type of application. I am thinking of bloodwood or paduak for the outer lams and maple for the inner.

Thanks in advance.

[Jamie Buxton]

Really -- the legs are going to be only 3/8" thick? So the three laminates will each be 1/8" thick? If so, most any wood will bend to the gentle radius I'd imagine you'd be using.

The usual advice is to use a glue which doesn't creep. Urea-formaldehyde and epoxy are two examples.

Seach on this board for "bent lamination".

[J. Z. Guest]

Ash is famously good for bending. It looks similar to Oak, but without the rays and with a much wilder grain pattern. It costs about 1/2 as much as oak in my area, and I just love it. The sawdust smell is sweet rather than acidic like oak's.

[Joe Chritz]

Check some of the woodworks shows. David Marks used bent laminations regularly and the system seems pretty straight forward.

It is unlikely that a bend for a leg will be so severe to tax any wood that is cut to an 1/8" so just about anything should work for you.

Joe

[Frank Drew]

Duncan

You said the legs need to be 3/8 x 2 x 30; did you mean that the individual plies would be 3/8"? If so, that might or might not be fine, depending on the curvature of the finished legs. A greater quantity of thinner plies often gives better results, though.

I'm with Jeremy in liking Ash for bending, but in a thin enough ply many woods would work well, depending on your design ideas (color, grain, etc.).

If you meant that the legs themselves would finish at 3/8"x 2", well, I don't know what to say. Was it a typo, and you meant 1-3/8"?

[Robin Cruz]

I just bent last night as a test several about 1/8" width (mostly a hair thicker) 4" wide 22" long pieces of red oak.. The bend or the arc was about 1 3/4" measured from center if you drew a line to the end. I did not glue as it was a test to see if the wood would bear up without breaking.

They bent with no problem other then the strength needed to close the form (using Bessey clamps) which was significant. When released they popped back to straight with amazing force.

Someone had suggested 1/4" width laminations, but I would not think based on the test above that they would bend that far without breaking.

[Bob Hallowell]

Wood that bends Hmmm.. seems like most wood I want to stay flat bends on me

Bob

[Peter Quinn]

I have some 8/4 maple off cuts in the garage that can nearly go around a corner after a year in non climatized storage. I think with a thin kerf resaw blade and layers of proper thinness almost any wood can be used for bent lamination.

I understand ash has a reputation for being particular good for steam bending but was unaware it offered a particular advantage for bent lamination. The down side of ash is that it is ugly IMHO.

At work we used west systems epoxy for most form bent laminated curves. Fully cured squeeze out tends to be unpleasant to remove. Remember not to glue your work to your forms (and please don't ask why I emphasize this).

[David DeCristoforo]

If you are using 1/8" thick layers, just about any wood will bend fine. But different woods are more "suitable" for strip laminating. Denser, lighter colored woods like maple are more likely to show the glue lines. Darker, open pored woods like mahogany will tend to hide the glue lines better. Ash and oak are kind of in the middle being very open pored but lighter in color. Also, woods like cherry and walnut fall in the middle range but for the opposite reason, being darker in color but relatively closed or small pored. In any case, using sequential strips will minimize the "layered" look. Try to cut your strips from one piece of wood and glue them together in the same order in which they were sawn.

[Chris Padilla]

Fully cured squeeze out tends to be unpleasant to remove. Remember not to glue your work to your forms (and please don't ask why I emphasize this).

A la David Marks: a belt sander with some 60 or 80 grit does the trick! It is funny because David always pauses/hesitates just a smidge when he gets ready to belt-sand his laminations...almost like he'd rather not do this but it is the best way to handle it!

[Peter Quinn]

A la David Marks: a belt sander with some 60 or 80 grit does the trick! It is funny because David always pauses/hesitates just a smidge when he gets ready to belt-sand his laminations...almost like he'd rather not do this but it is the best way to handle it!

Yup, that's the way the boss had us do it at my last job. Parked in front of a 2400 CFM 38" fan in the gable end of the building, just belt sand away and blow that crap out the hole in the building. Wonder how the neighbors liked the taste of cured epoxy? Like a moron I tried to use a card scraper once. OOPS.

I always thought David Marks was thinking "Can't I get an apprentice to do this, I'd rather not do this at all!" When is Festool going to come out with a belt sander?

[Christof Grohs]

Really -- the legs are going to be only 3/8" thick? So the three laminates will each be 1/8" thick? If so, most any wood will bend to the gentle radius I'd imagine you'd be using.

The usual advice is to use a glue which doesn't creep. Urea-formaldehyde and epoxy are two examples.

Seach on this board for "bent lamination".

Unibond 800 would be good for this application.

[Duncan Potter]

Thanks all for the responses. If I proceed with this I'll post some pics.............