Question about "bending" wood

[Boz]

I have limited experience working with wood, but am eager for the challege. The 4-player cardboard control panel I've been modeling has rather large symetric curves in the 3 and 4 player positions. When working with rather thick corrugated cardboard, making the curves was easy as pie. BUT, I'm positive that doing this with 10-ply oak plywood will take some special wood-working methods that I'm not aware of.

Can someone steer me in the right direction to accomplish what I'm after.

Thanks

My project link

[shardian]

I'm not woodworking vet, but I don't think you'll be bending 10 ply plywood any time soon. Your best bet would be to build up the side walls with several cuts of 3/4" ply in the curve of your choice. Glue and stack several layers of ply and there you go! Sand and putty the final side to get it smooth.

[Boz]

Well, I saw something very similiar at a supermarket. They built twin arches out of plywood. When I examined the structure I found that they cut sections out of the plywood and bent the wood to make the curve. I'm hoping to stain the wood so I don't know if putty is going to look right.

Hmmmpphhh!!!  There *has* to be a way to do this. Soak in water?

[ahofle]

Just guessing, but the furniture you saw was probably bent before the glue between the layers of wood dried.  Trying to bend it afterwards is probably going to be futile.

[Turnarcades]

  You could go for a less sheer curve on the base and just bracket the inside corners, then use wood filler or fibreglass filler to smooth round the corner. Once rubbed down it could look really good, but bending wood is something that should only be done in the manufacturing process as it compromises the rigidity of the wood anyway.

Or like has already been suggested, layer the wood and glue them together, then smooth that of for a nice finish. This may make the final item very heavy though and also make it look clumsy on the inside, so decide carefully what you are going to do.

Most people who have curved control panels choose to keep with a strong, squared box for strength, as well as practicality.

[Brax]

To bend wood you need steam. Lot's and lots of steam. In cedar strip canoe building we use an abs pipe to hold the wood and direct the steam into it from a kettle. These are just thin strips though. The glue in plywood won't stand up to this treatment.

I've also worked for a company than made the frames for laminated (plywood) circlehead windows. The plys are placed on a curved form during glue-up and clamped in place during the kiln drying phase.

You're not going to bend plywood of any significant thickness after the fact.

[babydickonboard]

well, i don't know if this would work for you, but when i was building the transition to my skateboard ramp, it was nessesary to find a process of bending all of the sheets of plywood.  what i did, was for the first layer, i used 3/4" plywood and cut a whole bunch of 1/4" deep noches into it. (its called keefing or something similer.) then for the next layer i used 1/2" plywood, and keefed it like 1/8" and soaked it  in water all day long. for the final layer, i skipped the cutting process (which leaves slightly noticible bumps) and let the plywood soak all day.  I then put an increasing amount of wieght onto the center of the board, allowing it to bend slowly of the course of a day or two. This will give the final layer a completly smooth curve, while the pieces behind it give it strength.



i think it will be impossible with a single 10 ply piece of plywood tho.....

[NoOne=NBA=]

For a long single arch, "kerfing" is a good method.
It allows the wood to bend, but won't allow it to bend tightly.

For intricate curves, I would go with a substructure covered with a single piece of very flexible facing.
That is the easiest method of getting multiple curves.
The nice thing about this method is that you get the strength of the substructure, without the hassles of multi-ply gluing.

You would have to build a jig for multi-ply gluing anyway, so why not just make it part of the finished product, rather than throwing it away when you are done?

[Boz]

Kerfing is what I saw with the plywood at the grocery store. The arches were actually part of the remodel they are going through and they were outside about 10-feet off the ground (something for people to walk through as if they were doors). This is the method I used to create the rounded corners on my cardboard control panel mock-up. I anticipated this would probably take a lot more effort and thought with wood, but I guess I didn't know just how much.

I've thought about a couple of ideas and these don't seem too bad from my point of view, though, again, I haven't a clue how hard it would be.

Option 1
Instead of kerfing, I could cut very explicit triangle cuts as far into the plywood as possible without cutting through. Then I could bend the outer most "ply" to my liking. The downside is that although it seems like it would be structurally sound, I would still end up with multiple flat faces in a faux curve.

Option 2
I could buy a couple of big blocks of oak from one of the specialty stores here in town and cut my curve to size as necessary. The downside to this is the amount of wasted wood for the cut and the REALLY expensive prices for blocks like I'm talking about.

Option 3
Block the curve out as much as is possible, fill with wood filer or fiberglass filer, then apply a sheet of oak laminate. The downside of this is that I don't even know if you can stain a sheet of laminate, plus, the grain would be significantly different from the oak plywood.

None of these options really appeal to me. I'll likely spend more time on getting these curves right than I would building and wiring the entire control panel.

[Orclord]

http://www.ipirti.com/product_dev_16.htm

[shardian]

Here is an idea: Cut three curve sections from plywood, like in the stacking method. Space them apart with 2" spacers and screw together. Face the much lighter structure with a veneer facing.

[zaphod]

What I've seen done on This Old House with curving banisters is that they take the length  (plus some extra) they need and run it through the table saw to make very thin strips (1/8"?).  They have a jig that has the inside curves they need.  They glue the strips together and immediately attach the sandwiched strips to the jig with clamps.  The individual strips will slide out the ends enough to make most any curve.  Then when it has dried, they finish it up with sanding and final cuts.  This way you'd end up with a smooth curve and have it very strong.

I may not have explained this very well but perhaps it gives you some food for thought.

[Quarters]

mMke your curve from whatever wood you like then glue on some oak veneer. You can get veneers that are 2 and 3 ply. stain as with any other oak.

[GadgetGeek]

This project (http://forum.arcadecontrols.com/index.php?topic=46723.0) has a curved keyboard drawer.  There is plenty of discussion on how to create this curve.

[Boz]

http://www.ipirti.com/product_dev_16.htm

Oooooooooooooooooooooooooooooooooooo.   

Google turned up less than 100 results on flexiply and many of them look like they are outside the US, my home. I bet shipping would be a beast! That's VERY cool technology though.

[Boz]

Here is an idea: Cut three curve sections from plywood, like in the stacking method. Space them apart with 2" spacers and screw together. Face the much lighter structure with a veneer facing.

This actually sounds like a viable solution and something I might be able to handle with the limited degree of experience I have with wood.

U dunno yet. I need to read through the project that GadgetGeek linked first though.

However, since Quarters said I can stain as necessary, the verneer is looking better and better the more I think about it.

[Boz]

Ok... I just checked the post (scanned it for the pretty pictures, really) that GadgetGeek just mentioned (thanks, by the way) and it looks like probably the best method for creating my curved fronts. You just gotta love DrewCarey and his willingness to help out.

I figure as long as I can build substructures (NoOne=NBA=, thanks) with enough "oomph!" to support the top and the inevitable weight it will bear -- by people pushing down -- I should be ok with those curves.

I like both the idea put forth in the post mentioned above as well as the idea of using a verneer.

That's 1,000 points to everyone who responded. Thanks Guys! This hobby / project would be MUCH, MUCH harder with out ya'll.

-Brian

[DrewKaree]

B, kerf the wood.  You have a sawboard.  It's nothing more than repetitive cuts over and over again until you reach the curve you wish to attain.  It's not only going to be the easiest, it's going to be FAR more foolproof than building up or removing something that may or may not work.  Also, from the size you're going to be doing, it's not going to affect the structural integrity of your CP AT - ALL!

For a good idea of what you'll need to do, how to achieve it, and possible results, take a look at this thread:

http://forum.arcadecontrols.com/index.php?topic=49644.0

DO NOT - DO NOT - think that just because he was dealing with MDF and you're dealing with oak ply that you won't be able to achieve this.  I've used this technique to round the ends of cabinets in people's kitchens with NO PROBLEMS WHATSOEVER.

If you're SERIOUSLY bugging about it and have to have the curve, you could also do what I did and miter that area.  I didn't need/want a curve, but since you do, sand it to the curve you wish, but it's SO easy to just kerf it, I waited until now to even bring up that option.

Kerf it.  You know in your heart of hearts after looking at that link that it's the right way to go.  NoOneNBA gave you the right direction to go in.

[Howard_Casto]

If you haven't started already another suggestion.  At your local lowes they have a material that is similar to flex-ply used for floor underlament.  It is a wood-based product but it doesn't have any grain to speak of.  It bends quite well though.  So if you are going to paint the whole thing, then use that. 

Kerfing is the right way to do it, but main it's a pain in the butt.  You'll go mad after the 631st cut.  I know I did. 

[Boz]

Kerfing is the right way to do it, but main it's a pain in the butt.  You'll go mad after the 631st cut.  I know I did. 

I dunno. I thought about doing a number of things for the first cabinet that would make it look really good. In the end, I pretty much decided that my limited wood-working skills (and the patience it requires to spend 4 hours setting up a jig for a cut that takes 60 seconds) would probably benefit more from the overall experience than from a single piece that takes forever to get "just right". My CP will have corners and edges like so many of the beginning cabs have.

BUT... it'll be 5 feet wide! 

* In2ishun nod's and smiles at Drew

[BackAgain]

I just checked out your project link and your CP.  I'm just wondering why you are using 3/4" plywood for the sides that need to be bent.  You could use 1/4" plywood that would EASILY bend to that radius without any cutting or steaming.  You could probably make those bends with 1/2" plywood as well, but you might need a few extra braces you probably don't want to mess around with.  The 1/4" ply will be PLENTY strong to take the abuse your panel will get from enthusiastic button smashers.

Just my thoughts.  I bent 1/2" plywood for the curves on my cab with no problems.

[Boz]

I just checked out your project link and your CP.  I'm just wondering why you are using 3/4" plywood for the sides that need to be bent.

Someone hasn't been paying attention. In both this thread and my project thread I mention that I will NOT be bending wood on this go-around. I've opted for that run-of-the-mill, boring, angled CP. As soon as I have at least one cabinet under my belt, I'll feel more free to be creative.