I need accurately thin sheets of hardwood to make large panel a bent form lamination

[Dolmetscher007]

Essentially need to make my own plywood. I am trying to find where I might be able to source larger sheets of hardwood. The species of wood is pretty irrelevant; whatever is cheapest and most available... most likely poplar. The "plys" must be between 1/6th and 1/8th of an inch so I can spread glue on them, alternatinv grain directions with each ply, bend them over a simply frame, strap them down all over possibly even use a vacuum bag, and let them harden in that shape. 

The mold is a simple rectangular cube with 4.5" radius rounded corners. The end shape will basically be a 3/4" thick, x 20" deep x by 28" deep capital letter "U" but with a longer flat area between the curves. I guess, kind of like a very small "half-pipe" for those of you out there that used to ride skateboards. 

Anyway... If you Google the word "veneer" you will find nothing but decorative veneer that are too thin, too pretty, and FAR too expensive. 

Is what I am looking for just not something that is really out there on the market? If it is, and you know what these "plys" are called, I would love it if you could let me know where to look.

Thanks guys!

[Coop]

What would be the ideal size of these sheets if you can find them? Your final size of each sheet will be 20” x 28”?

[lewisc]

Have you had a look at skateboard veneers?

https://www.roarockit.com/veneer-1/

[wtnhighlander]

Do you need sheets wider than you can resaw and plane? Marc demonstrated in one of his videos (basket weave hamper, maybe?) that using a sled and tape allows the planer to finish boards down to about 1/32".

Second question: Why alternating grain direction? That will make the resulting shape only half as rigid as it would be if all the grain was aligned. Plywood uses that format to counteract wood movment for flatness.

[Tpt life]

Most of those processes start with buying a billet and re-sawing it. 

[Dolmetscher007]

Yeah... I know that most of the time bent wood lamination applications never get much wider than around 6" or less. So, most of the time, people just buy a piece or 8/4 and get to re-sawing it into 1/16-1/8" sheets. 

The problem is the size of what I need to make.  I've attached a basic SketchUp drawing of the object with all it's final dimensions. I suck at match, so I cannot tell you the exact length I need, probably something no longer than 4 ft. long. I can adjust the dimensions slightly based on price and/or availability of the sheets (plys) I need. 

I have seen that Home Depot sells 1/8" plywood from Columbia Forest Products called PureBond Radius Bending Plywood. It is just 4' x 4' sheets of 2-ply basswood plywood that is thin enough to bend around a wide enough radius. I have a good feeling it would work for what I need. Problem is... it costs $32 per sheet. In order to get up to my 3/4" thickness, I would have to stack 6 sheets of this 1/8" stuff together. I would be able to rip each 4' x 4' sheet in half, so I'd only have to buy three of the $32 sheets. But I have to make two of these things, and I am not spending $200 for $45 worth of plywood that I actually had to ply together myself. Okay... that last bit is a bit ridiculous, but you get what I mean. 

 

[Dolmetscher007]

39 minutes ago, wtnhighlander said:

Do you need sheets wider than you can resaw and plane? Marc demonstrated in one of his videos basket weave hamper, maybe?) that using a sled and tape allows the planer to finish boards down to about 1/32".

Second question: Why alternating grain direction? That will make the resulting shape only half as rigid as it would be if all the grain was aligned. Plywood uses that format to counteract wood movment for flatness.

Ya know... I never thought about it like that! I watch a lot of YouTube videos and no matter what, whenever someone is talking about gluing up thin sheets of wood into a lamination, they always point out that they are alternating the grain directions for added strength. For example, Gibson ES-335 guitars have a 3-ply, maple / poplar / maple laminated top that gets glued and pressed in something like an 80 ton heated press, and Gibson has always pointed out that they crisscross the grain for strength and rigidity. 

All the major drum companies also always point out, when they are making their drum shells, they use thin sheets of wood plys in with a crisscrossed grain for strength and rigidity. I can see what you are saying though. However... if the grain direction of each sheet is always facing the same direction, it will make the resulting sheet stronger (more resistance to bending) in one direction over the other. If you crisscross grain with each ply, you ensure that the final sheet will be just as rigid along the x-axis as the y-axis. 

[Mick S]

I would look into bending ply - special plywood that bends and can be formed to a radius. It comes in 4 x 8 or 8 x 4 sheets in varying thicknesses. I've used it on a few projects and found it very easy to work with.

http://packardforestproducts.com/bending-plywood/

 

[wtnhighlander]

22 minutes ago, Dolmetscher007 said:

 If you crisscross grain with each ply, you ensure that the final sheet will be just as rigid along the x-axis as the y-axis. 

Exactly. The crossed plys improve STABILITY, at the cost of rigidity in one direction, gaining it in the other. 

[pkinneb]

I've used the bending ply as well and think it would work, well except for maybe cost but not sure you will be able to do it much cheaper either. FWIW the 1/8" is closer to 3/32" I may have a 4'x4' piece in the shop if your interested in seeing how tight it can be bent I could try and snap a pic or two tomorrow.

[Don Z.]

17 hours ago, Dolmetscher007 said:

I know that most of the time bent wood lamination applications never get much wider than around 6" or less.

You don't need the entire width to be one piece.  The plies underneath will add to the strength.

 

 

[krtwood]

3mm Baltic Birch comes in 60"x60" sheets and is about $20 a sheet and will bend to that radius if you go across the grain of the outer plies.  Here's a video of me doing pretty much what you want to do:

 

[Chestnut]

This is something that you would have to make yourself. You could also look into a local WW guild and see if a member would be willing to resaw plys and sand them. A cabinet shop might be willing to do the same if you find one that does specialty work. The bending ply is going to be cheaper in the long run I'd bet.

[Dolmetscher007]

I called a lumber yard, and they have 1/8" luan plywood in 4' x 8' sheets. I've heard of luan. plywood from a lot of my contractor friends. They use it for interior panels like wainscoting and certain parts of cabinets. I've never personally seen or touched it. Do you guys, who maybe have some experience with luan. plywood, think that it can bend around a 5-6" radius without cracking? 

[Tpt life]

34 minutes ago, Dolmetscher007 said:

I called a lumber yard, and they have 1/8" luan plywood in 4' x 8' sheets. I've heard of luan. plywood from a lot of my contractor friends. They use it for interior panels like wainscoting and certain parts of cabinets. I've never personally seen or touched it. Do you guys, who maybe have some experience with luan. plywood, think that it can bend around a 5-6" radius without cracking? 

No. That is too tight a radius. 

[drzaius]

3 hours ago, Dolmetscher007 said:

Do you guys, who maybe have some experience with luan. plywood, think that it can bend around a 5-6" radius without cracking?

Not a chance bending across the long grain face veneer, but it might the other way. Did you watch the @krtwood video? He did a 6" radius with 3 mm Baltic Birch. You should give it a try. It's much better quality than the luan ply.