Bowed walnut question

[Tom Porter]

I'm not sure if this is the proper forum for this question but a moderator can move it if necessary with my apologies. A few years ago, I picked up several pieces of live edge black walnut from a local retired farmer. If I remember the story correctly, his son worked at a mill or had a small mill of his own or something like that. Anyway, the wood was nice and it was very cheap. Most of it was used for a variety of small projects like cutting and serving boards. I have two pieces I set aside for a bench or table but they have become significantly bowed over time. I can only assume they weren't fully dried or perhaps I didn't store them properly (they were in an unheated garage for a few years). They're about 40 inches long, 7 inches wide, an inch thick and still have the bark attached. If laid with both ends on a flat surface, the bow in the middle of one board is almost an inch from the surface and the other is about a half an inch. Last summer, just out of curiosity, I put some wet shop towels between them with the concavities facing, clamped them together until they squeezed shut and set them in the sun for a few days. When I unclamped them, they were a lot closer to flat; not perfect obviously but enough to work with. However, since then, the bow has returned.

Are these boards pretty much done for except for small projects? I considered trying to bring them close to flat again and edge join them using floating tenons and orienting the bowing in opposite directions but I figure the stress would just make the board really wonky. Is there anyway to reasonably make these boards useable at near their full length?

Bear in mind, this is more an exercise in me learning more about wood movement than an imperative to use this particular wood. I'm just curious.

[Steve Demuth]

You will likely never get them flat through manipulation of moisture content and stress alone. If they are worth something to you, it would be trivial for a piece that size to rig up a steam chamber. 90 minutes in a steam chamber and they can pressed flat (actually, clampled just slightly over flat in the opposite direction) and will stay that way. But it's a lot of work for a board, and the character of the walnut will suffer - steamed walnut is just muddier than kiln dried which in turn is muddier than the (I am guessing) air dried wood you have.

[Ron Citerone]

My gut tells me manipulations are not going to work. I would think you would be better off using it for small stuff. Others with a lot of live edge/slab experience should chime in though.

[lowell holmes]

I would rip them into three or four pieces and glue them back together with the bow opposite in each piece before throwing them out.
I would use 3/8"x1 1/2" on maybe 12" centers on the seams.

[Jim Dwight]

How much force is required to flatten them? If it is something a screw can pull out, you could use them in a structure where they will essentially be clamped flat. If you don't think a screw will hols them, then cutting them up is probably the best option. I finished my new dining room table in January. The top is 10 feet long and is made up of 6 boards for a total finished width just over 42 inches. My jointer is far too small to joint a 10-12 foot board on it's face. So I just ran them through the planner. At least one was significantly bowed but less than your boards are over a much shorter distance (my worst one was no more than 1/2 inch over 10 feet). Finger pressure would push it back. I used 8mm dominos in the glue joints and the top of the table is flat. So lesser amounts can be managed but an inch over 40 inches is a lot.

[Jim Matthews]

What's the typical width of your projects?

Door rails, legs, etc. are not usually more than 3 inches wide. While the stock may not be suitable for large panels, it should yield plenty of usable parts.

[Austin Perera]

I think that's going to be a difficult situation especially with the slabs only being an inch thick to begin with. The one time I built a live edge table I specifically went with a 2 in thick kiln dried black walnut slab to help avoid this issue. There are large wood shops that can do live edge slab leveling and planing, but I think this is a situation where you're better off just starting with new slabs for anything but small projects from them.

[Tom Porter]

Thanks for the replies. Pretty much what I expected. I might experiment with them a bit since I have nothing but time to lose. I'll post another reply if I have a result that is either successful or disastrous.

[Austin Perera]

The practice is definitely helpful, especially to hone a technique for cleaning up the edges. My slab also came with the bark. I found that a two handled bark stripping knife was invaluable, and they aren't very expensive. For sections of the edge that were tight, a dremel with carbide grinding tips was a big help. You can also practice your epoxy techniques on it - taping, using a torch to get the bubbles out, mixing different dyes to see how the final result looks, etc.

[Doug Dawson]

I'm not sure if this is the proper forum for this question but a moderator can move it if necessary with my apologies. A few years ago, I picked up several pieces of live edge black walnut from a local retired farmer. If I remember the story correctly, his son worked at a mill or had a small mill of his own or something like that. Anyway, the wood was nice and it was very cheap. Most of it was used for a variety of small projects like cutting and serving boards. I have two pieces I set aside for a bench or table but they have become significantly bowed over time. I can only assume they weren't fully dried or perhaps I didn't store them properly (they were in an unheated garage for a few years). They're about 40 inches long, 7 inches wide, an inch thick and still have the bark attached. If laid with both ends on a flat surface, the bow in the middle of one board is almost an inch from the surface and the other is about a half an inch. Last summer, just out of curiosity, I put some wet shop towels between them with the concavities facing, clamped them together until they squeezed shut and set them in the sun for a few days. When I unclamped them, they were a lot closer to flat; not perfect obviously but enough to work with. However, since then, the bow has returned.

Are these boards pretty much done for except for small projects? I considered trying to bring them close to flat again and edge join them using floating tenons and orienting the bowing in opposite directions but I figure the stress would just make the board really wonky. Is there anyway to reasonably make these boards useable at near their full length?

Bear in mind, this is more an exercise in me learning more about wood movement than an imperative to use this particular wood. I'm just curious.

Save them, age appropriately under good storage conditions, then when the opportunity arises rip them into thin strips on the band saw and use the strips for bent laminations.