How to bend wood like this - Outdoor furniture project

[Ron Selzer]

yes it is very dusty to work with, did a lot with it at one time in my work life. get bunks of 3'x10' up to 5'x12'. was in shape when handling the 5'x12'. Always hated working with the imported mdf, liked domestic better.
Ron

[Alan Lightstone]

OK. Now the next problem. I have built 8 forms, to be attached to each other to make the required 5-1/2" height to bend the wood laminations against the jig. They have been rough cut on the bandsaw, and then using a pattern bit made as close as possible to the pattern:
Bending Jig Stacked.jpg

I have also on the drill press drilled a number of holes to use clamps to hold the wood against the bending jig:
Jig Pattern for Bending with holes drilled.jpg

My present problem is how to drill all those holes in the 8 pieces of 3/4" MDF. Now the holes lining up perfectly would be nice, but certainly not as important as the edges of all the pieces lining up so that the wood laminate pieces have a smooth contour when bent against it.

Taking every piece individually to the drill press is really a non-starter. They are too heavy, and want to tip off the drill press. Plus no way I could remotely handle lifting all 8 pieces together.

So lets assume I attach all 8 pieces plus the pattern together. How do I then, without the drill press, drill those 1-1/2" diameter holes in 6" of MDF accurately? The pattern on top would act as a guide to some degree.

[Phil Gaudio]

It's easy enough to build a temporary auxiliary table for your DP. Here is the project I am currently working on: that table supports the 50 lb slab that will become the seat of a bench.

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[Alan Lightstone]

I did just find a 2" diameter hole saw whose description says it can drill up to 6-1/4" depth.
https://www.grainger.com/product/SPY...8HY29?opr=ILOF

I can't imagine how difficult it would be to remove the 6" plug from the hole saw after each cut.

[Alan Lightstone]

OK. The forms are built. Just waiting for a deeper hole saw to drill holes in the forms for clamps. And yes, perhaps I should have made the middle hollow. It weighs more than I can possibly lit.
Bending Jig Form Before Large Holes Drilled.jpg
Now the $64,000 question.

I was only able to get kiln dried white oak from my supplier. He laughed when I asked for air dried white oak. So clearly not as easy to bend. Oh well, that's what I have. So for technique, looking at the above suggestions I have a question.

No doubt I could make it out of a boatload of bent laminations from the white oak without steaming. But I do have the materials to build a large steam box and just bought the steam generators from Rockler (which can be returned). But will this allow me to use thicker laminations, or is this just a waste of time and money considering the kiln dried white oak that I have?

I was thinking of trying the Michael Fortune technique of steam bending the wood in both directions to make it more pliable, and then doing bent laminations with them, as springback is a total no-go for me. https://www.finewoodworking.com/2007...ding-technique

Is this double the work and will the kiln-dried white oak just not steam bend any thicker than just bent laminations? Again, these will be 5-1/2" tall and 1-1/2" thick, so lots of laminate pieces to be bent.

[Steve Demuth]

Alan,

If you're steam bending them before doing a lamination glue up, then a little spring back is not a big problem. A little bit can even be helpful in getting the lams fit onto the form.

As for the steam bending of kiln dried white oak: You should make a test piece 3/16" thick (or maybe 1/4" if you're feeling really adventurous), steam it, and see how it bends. My experience is that at those thicknesses, the difference between air dried and kiln dried isn't all that significant (it certainly is if you go much thicker, but you won't get great laminations from anything thicker anyway). Again, you don't need a perfect, zero spring back bend, because the glue up will take care of any modest spring back quite nicely as long as you use a glue that won't creep on you.

The key to getting near perfect laminations in a situation like yours is to use a glue with adequate open time, and start the clamping at the center of the bend, working out symmetrically. Use lot's of clamps. Roll the laminations down onto each other as you work away from the center. It can be useful, if you can swing it to clamp with cauls that give you a lever point, so you can push each successive caul both down and away to smooth and eliminate any bulges in the lams.

[Alan Lightstone]

Making the steam box is next as I'm finally done with the form.

I've been watching many videos on wood bending. This one from a very talented furniture maker takes things to an amazing extreme. Not my style of furniture, but very impressive work:
https://www.youtube.com/watch?v=eZOY9DBXprI

Another talented Aussie. Lots down there.

[Jim Becker]

Pedulla is one of my favorites. He's referenced the other fellow's work (the guy with the bending fixture) when discussing steam bending, actually.

[Alan Lightstone]

Pedulla is one of my favorites. He's referenced the other fellow's work (the guy with the bending fixture) when discussing steam bending, actually.

The "other fellow" Darren Oates, has unfortunately taken all his content off of Youtube. Pity, as I hadn't downloaded it as I saw no need. It was very instructive, and he produces beautiful furniture.

[Jim Becker]

Strange...he has a large subscriber base. I wonder what happened.

[Alan Lightstone]

So, my next question. I'm building the steam box now (big sucker - 89" long x 12" wide x 7" tall). Considering how large the size of the required steam box is, my question is regarding steam generators.

I purchased two steam generators from Rockler. But should I be using two, versus returning one and just using the single one. I will have pressure relief hole/holes in the box, but I wonder if the far end will get enough steam to help the wood bend. In particular this will be kiln-dried white oak, so that's not in my favor to start with. And if I use two, where to place them.

[Bradley Gray]

I have an Earlex steamer. Works well but only runs for an hour before it's out of water. With two, you could stagger the start. The biggest issue is insulating the box. A thermometer is really helpful. I bend cherry and walnut 1 x1" squares for music stand legs. They need 1 1/2-2 hours. A metal band with end blocks reduced my breakage from 60% to 20%.

[Alan Lightstone]

I have an Earlex steamer. Works well but only runs for an hour before it's out of water. With two, you could stagger the start. The biggest issue is insulating the box. A thermometer is really helpful. I bend cherry and walnut 1 x1" squares for music stand legs. They need 1 1/2-2 hours. A metal band with end blocks reduced my breakage from 60% to 20%.

I thought of staggering the starts, but I'm wondering if a single steamer can provide enough steam for that large a volume box.

[Bradley Gray]

If you're using the Ealex you will have plenty of steam. Go nuts insulting the box and make a steel backer with end blocks. You have to compress the fiber on the inside of the curve and keep the outside fibers from fracturing.

[Alan Lightstone]

If you're using the Ealex you will have plenty of steam. Go nuts insulting the box and make a steel backer with end blocks. You have to compress the fiber on the inside of the curve and keep the outside fibers from fracturing.

How do you insulate the box? It's 3/4" exterior plywood. I'm using the Rockler steam generator.