# Is concave bent lamination possible?



## lots2learn (Aug 12, 2009)

I'm dreaming up my next project and have a design element in my head. It's a concave shape. What I mean by concave is, it's like the inside of a bowl. It will be on a much larger scale, like a set of drawer fronts or the side of a table. Not deep at all though, just the subtle shape. It looks to be a large bent lamination project. While I've used bent lamination on a few pieces the additional bend (like folding a piece of paper into a tube and then bending it) has me perplexed. I can't afford a very thick piece of wood to carve the shape out of (although the form will be pricey I'm sure). The idea is to bend laminate some bending ply, or homemade poplar laminate and then veneer the outer shell. I was thinking of maybe taking one or two plys at a time, wetting or steaming it somehow and trying to work it around a form before putting it in a veneer bag. Do you guys think that will work? Impossible? Any other ideas?


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## Loren (May 30, 2008)

Concave, convex. It can work. It's done for backs and fronts of
low-end archtop guitars.

At some point there's a point of no return if bending in more
than one axis where your material will fall apart.


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## dkirtley (Mar 11, 2010)

Cold molded boats, salad bowls, and skateboard decks are made that way too.


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## saddletramp (Mar 6, 2011)

Instead of trying to force your laminations into a concave form, you could do your form from the other side allowing you to do a convex lamination.


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## docholladay (Jan 9, 2010)

I haven't tried, but would say it should be doable if the curvature is gentle enough. If too much of a bend, probably not. I would suggest that the veneer be wet to make it more flexible when applied. I also would recommedn vacuum bag veneering. Can't think of any other way that you could clamp it for solid bonding.

Doc


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## BobTheFish (May 31, 2011)

http://www.woodweb.com/knowledge_base/Vacuum_Veneered_Drawer_Faces.html

hope that helps


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## BarbS (Mar 20, 2007)

Or you could try Kerf-bending. Lots of links to it on Google:
http://tinyurl.com/3ncx23j


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## Gregn (Mar 26, 2010)

Are looking to do something like this?
http://www.wikihow.com/Bend-Wood


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## sras (Oct 31, 2009)

Cool idea - you could end up with an impressive shape. If I were attempting this, I would lay strips on a form. I have done this with a strip built kayak. The form can be built up of a set of cross sections of 1/2-3/4" plywood spaced every foot or so.

If the curvature is subtle enough, you could use some fairly wide strips. Maybe taper them at the ends - wider in the middle. I would try to use the thickest strips I could as well. The kayak used 1/4" thick strips, but if the shape is not too aggressive, I would see if 1/2" or greater would work. The kayak has fiberglass on each side, but I would think thicker wood can give a strong enough piece.

The technique I used for the kayak was to bevel the edges of each strip to get a tight fit and create a nearly invisible joint. I used a small hand plane and a LOT of test fits for each strip.

Once the shape is built up, a bit of hand shaping will create a smooth form.

If you are set on using veneer, maybe the strip built technique would be a way to get a base structure and then try to form veneer as a top layer.


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## sras (Oct 31, 2009)

Here is a blog on the technique for kayak building. It shows you what I mean about the form setup and the rolling bevel for the edge joints.

Be careful! You read too much and you might get sucked into building a kayak!


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## rmoore (Mar 9, 2011)

I just saw this posted. http://lumberjocks.com/topics/27829 Hope it helps.


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## shipwright (Sep 27, 2010)

Steve is right. You could do it with narrow strips, like strip planking a canoe.

If it were me, I would shape the pieces (each will be narrower at the ends than the middle for a bowl shape) according to the shape you're trying to achieve. Lay up about three layers of thin stock on opposing diagonals.

You can make any shape you can imagine that way. As David said, look up cold molded boat construction.


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## DLCW (Feb 18, 2011)

Here is a bathroom vanity I did several years ago using bent form lamination. You take a board, resaw it into 1/16" or 3/32" veneer and glue the veneers back together using a bending form. I built my bending forms from 3/4" MDF. You create two sides of the form and with that you can get concave or convex.

The drawer faces in the vanity are all bent form solid wood. The doors on the quarter round medicine cabinets are coopered and smoothed inside and out using a grinder, scraper and sandpaper.


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## lots2learn (Aug 12, 2009)

Thank you everyone for your input. It never ceases to amaze me how many people go out of their way to be helpful around here. I'm afraid that I have a creative block or something, but you have all given me options to think about. Once I have my design hatched out I'm definitely going to incorporate some of these suggestions.


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## Radiuswoodguy (May 20, 2010)

There are many ways to accomplish your goal. Years of bending taught me keep it simple, Vacuum is wonderful and has its limitations; your lamination may be best done with strap clamps the wide ones are cheap and pack tork. The skill comes from producing the stock one needs to clamp, if you got that part "no worries". A good compatible form and good glue proper cover sheet. There are tricks for compound bending's. Send me an email with drawing and approx. radius I may be able to lead in the right direction Clamping is all about pressure lots of ways to accomplish that!


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## Radiuswoodguy (May 20, 2010)

There are many ways to accomplish your goal. Years of bending taught me keep it simple, Vacuum is wonderful and has its limitations; your lamination may be best done with strap clamps the wide ones are cheap and pack tork. The skill comes from producing the stock one needs to clamp, if you got that part "no worries". A good compatible form and good glue proper cover sheet. There are tricks for compound bending's. Send me an email with drawing and approx. radius I may be able to lead in the right direction Clamping is all about pressure lots of ways to accomplish that! Radiuswoodguy.com


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