Bending Plywood

[Ernie]

Is there any secrits to bending plywood? My wife and I are currently studying plans and considering modifying the plans we have. Just wonder where the limit is for bending plywood and what thickness plywood should we use if the exterior roof is plywood? This will be our first trailer.

Ernie

[mikeschn]

I believe it was Tom S that posted a photo of bendy plywood. Using that I think you can do a 3" radius.

However most other plywoods are not as bendy friendly.

When I built the first Benroy I bent 1/8" plywood around an 18" radius. I broke two sheets before I got one to work. That's with the grain running along the length of the teardrop.

When I built my second Benroy I ran the grain along the width of the teardrop and 18" was not a problem. How much smaller can you go? I don't know. I'll have to wait for others to chip in...

In the meantime, let me turn this into a poll...

Mike...

[randy chesnutt]

ernie, there is bendable plywood. you can get it in different thickness and it comes bendable end to end or side to side. check with your lumber supplier. i had to make a curve cabinet door. i set my first peace down on the jig and then i glued the second on top of it. when the glue dried i remove it from the jig and the curve was there for good. it's font to work with.

[Gaston]

the radius at the lower front of my teardrop design is 6" and the radius at the lower rear is 7 1/4 so I sure hope I can bend 1/8" luan that tight

[Arne]

I know steaming allows more bending in regular wood and it may help in plywood, but would be a pain to do. Has anyone found if wetting helps? If so, just dampen the ply or a thorough soaking?

[dacrazyrn]

I got the 5.4mm (almost 1/4 in-Water resistant Luan) to bend around a 12 inch radius, but only after laying in the grass with towels on it, and pouring boiling water and ammonia on it and letting it soak for 45 min, flipping the luan and doing the same on to the other side.

[dwgriff1]

It depends on how "green" or "dry" the plywood is.

I bought 20 sheets a while back. They came off the pallet in one bunch. The outer sheets were drier and would not bend nearly as much. The inner sheets would bend very tight.

The lesson, I think, might be to incrase the humidity in a sheet you wanted to bend tight.

BTW, I buy 1/8 Asian, maybe lauan and maybe not, for $6.60 a sheet, but it is at the wholesale outlet -- cabinet shops etc.
If the price you see is too much more than that, talk to a cabinet shop. I have a friend who has a shop and orders for people regularly. He charges them 10% over his costs.

dave

[asianflava]

BTW, I buy 1/8 Asian, maybe lauan and maybe not, for $6.60 a sheet, but it is at the wholesale outlet -- cabinet shops etc.
If the price you see is too much more than that, talk to a cabinet shop. I have a friend who has a shop and orders for people regularly. He charges them 10% over his costs.

dave

That's about half what I paid!

[Arne]

Me, too, I've been paying just under $13/sheet pre Katrina..... my next tear will be cheaper, I'm only going to use half as much wood... no more 1,000+ pound tears for me....!

[goldcoop]

Hey all!

I bought 4' x 8' x 3.6mm Melopi plywood from the furniture plant in town (has since closed) for $3.oo/ sheet!

It didn't bend well at all!

I thought I was doing great just bending 22" R!

I think it's biggest problem was it was 3-ply, 1 face & 1 back veneer AND then a thicker core!

So I think we need to add number of plies to the list, the more the better for bending?!

Cheers,

Coop

[WoodSmith]

I know steaming allows more bending in regular wood and it may help in plywood, but would be a pain to do. Has anyone found if wetting helps? If so, just dampen the ply or a thorough soaking?

I used a wallpaper steamer to steam some ply that I bent for a cradle boat. It worked very well, and the larger 'dispenser' made it fairly easy to steam to whole piece.

[woodchick]

Have you considered kerfing it?

[madjack]

Have you considered kerfing it?

well it's like this...yes we have and in extreme situations we will but we are lazy and will spend an inordinate amount of time rigging up all sorts of ways to bend ply when 10min with a skill saw, rotozip or router would solve the problem....
madjack

p.s. I didn't catch you on your first post(or....) so welcome to our little band of builders and dreamers...the fact that you found AND posted is proof that you may need a couple of more bricks...so what are ya buildin and when do we get to see it..ya know pictures...we luvs de pics

[John Reilley]

Howdy
I bought bendabel Birch 1/8 inch 4x8 for the ceiling of my cubby. The sales guy rolled it up in a cilinder about a foot around. I have not used it yet but I cant see how it would not work. It ran me $ 30 a sheet and is darker than regulatr Birch.

John R

[asianflava]

Where did you get the bendable birch? I bought my 1/8 ply at Fine Lumber but never asked to see if they had bendable wood.