Edge of bent laminations

[Jim Tobias]

I'm working on some curved legs for a coffee table that are 5" wide and 1 1/2" thick using bending plywood as core and 1/8" thick solid wood as outside lamination. The edges of the legs will be exposed and I will be finishing the project with black tinted lacquer . The edges of the bending plywood appear to be very porous. What would be a good filling option on leg edges to get smooth. surface for finish.

Jim

[Todd Burch]

I would veneer it. You could epoxy it - light coat the first application (read: first day) to seal and apply a thicker coat (the second day) and sand (the third day).

[Rod Sheridan]

I vote for veneer also..........Rod.

[Jim Tobias]

Todd/Rod,
Thanks for the reply. The veneer option does seem simpler than going the epoxy route(Sand, sand, sand). I assume that the suggestion of veneer is that it will give me the best surface for the finish?
Also, shoul dI have any concerns about the strength of the curved laminated leg with the bending plywood? It seems to me that the solid outer layers would give it enough additional strength with the opposing grain.:confused:

Thanks for the input. Below is a picture of the apron lamination which is the same lamination process(except apron does not have solid outer layers) as the leg will be.

Jim
228504228505

[Jeff Duncan]

Yup, put a layer of veneer on and your good to go.

good luck,
JeffD

[Jeff Duncan]

Bendy ply has very little real strength and you need to be careful to make sure your legs are sturdy. From the pic you show, if I were to make these legs I'd do them out of laminated solid wood instead. If you think about it your legs are not going to be too much stronger than the 1/4" of actual wood your using for the faces. Maybe do some testing on the one you've already made....but I'd be very cautious using it as described.

good luck,
jeffD

[Tony Joyce]

You should have plenty of strength with the bending ply, especially using solid skins on the outside. Using 1/8" outside skins you will have some spring back. Two or three layers of veneer for the outside would give less problems with spring back. I would use the 1/8" thickness for the edges. The luan bending ply is very porous so use plenty of glue between the layers.

[Todd Burch]

Well, Jim... you know how to test it, right? Jump on it and see what it does!

[Rod Sheridan]

Hi Jim, yes the veneer will give you a smooth surface with consistent absorption of stain/finish.

The bending plywood will be plenty strong for the apron.

Try puting some weight on one of your laminated legs and see what you think. I think that unless the curve is so severe (poor engineering) it will be OK unless people start standing on the table.

That said, I always make bent laminations from solid strips.

Regards, Rod.

[Ole Anderson]

It will be interesting to see if the laminated leg section will have the strength needed. I would suspect that the majority of the strength will come from the two solid wood outside laminations with the interior plywood acting as a lightweight core, so that you really have a stressed skin structure. If the core of each plywood piece is laminated cross grain to the length of the leg, a lot of strength of the plywood laminations will be lost. Agreed that typically a bent laminated leg will use strips of solid wood, all grain being parallel to the length of the leg. I remember a couple of David Marks projects using the technique for bent legs.

[John TenEyck]

In my experience curved laminations with bending plywood are very stiff, especially when exterior side skins are used. But for the core itself, stiffness has a lot to do with the type of glue you use and the number of glue layers. I use Weldwood plastic resin glue or Unibond 800 because they are stiff and don't creep. You can increase the overall stiffness by adding additional glue layers, without increasing the overall thickness much. You do this by adding thin veneer layers between the layers of bending plywood. Each veneer layer gives you two glue layers, instead of one. You use more glue, but the benefit is increased stiffness.

John

[Larry Edgerton]

Bendy ply has very little real strength and you need to be careful to make sure your legs are sturdy. From the pic you show, if I were to make these legs I'd do them out of laminated solid wood instead. If you think about it your legs are not going to be too much stronger than the 1/4" of actual wood your using for the faces. Maybe do some testing on the one you've already made....but I'd be very cautious using it as described.


good luck,
jeffD

Ditto what he said.........

Larry

[Jim Tobias]

Thnaks to all for input and suggestions. That is what makes this place so great. You can get feedback from people who have done just about everything. After listening to all suggestions, I think it is probably wise for me to use thin solids to laminate the legs. Although I think the aprons are plenty strong enough with their makeup(3 pieces of 3/8" bendable ply with a 1/8" solid skin on the inside and outside). But , the legs(5" wide and 1 1/2 " thick) will be supporting an oval top(1 1/8" thick) with glass insert and will be 50" long and 30" wide.
Any more suggestions are always welcome. I continue to attempt projects that are new to me as I find that is the best way to learn and having Sawmill Creek as a resource makes it easier to dive right in.

Thanks again,
Jim

[Joe Spear]

I love your subject line: bent lamentations. Those bent laminations do cause a lot of sorrow and woe.

[Jim Tobias]

Joe,
I wish I could say that it was "tongue in cheek" wit, but it was just my bad typing!:o

Jim

[Alan Lightstone]

I'm also of the solid wood lamination and veneer the end grain school. Should look real pretty when done.

[Chris Fournier]

I'm working on some curved legs for a coffee table that are 5" wide and 1 1/2" thick using bending plywood as core and 1/8" thick solid wood as outside lamination. The edges of the legs will be exposed and I will be finishing the project with black tinted lacquer . The edges of the bending plywood appear to be very porous. What would be a good filling option on leg edges to get smooth. surface for finish.

Jim

If by tinting you mean an opaque lacquer then you could use automotive body filler, vinyl sanding sealer and then topcoat of your choice. This works very well. If by tinting however you mean a shader, then I'd use face veneers.

A four sides face veneer is fine choice and depending on the grain layout you can create a very "modern" or "from solid wood" look and the grain can show up slightly under the lacquer.

Don't be dissuaded to use the bending plywood by it's many detractors, it is a great product and certainly strong enough if used properly. Do however consider the joinery options at your disposal and make sure that the bent lam is robust enough to accept the joinery.