Redwood Slab Table Build

[Zuye Zheng]

Build thread for a Nakashima inspired redwood slab outdoor table. Due to dimensions and price, ended up getting one not fully dried, but decided to take a chance especially since it will end up outside. First time doing joinery so large and not working with dried hardwood, hopefully making semi-decent decisions.

Flattened with a scrub and a jack plane.
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Some butterfly keys to stabilize the cracks. Ended up using hard maple for the contrast even though it will be outdoors, hopefully wasn't a horrible decision and the finish will protect it.
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Nakashima inspired base from laminated 2x4's.
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Joined to the beam with a double mortise and tenon and dovetails. The beam was a BORG redwood 4x4 that was pretty wet, hopefully it doesn't do something crazy drying. The joint was very tight when dry fitting and glue probably wouldn't have done much with the wet wood so just a friction fit (but mostly since I couldn't get it apart again).
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The side panel is joined similarly at the top to supports that will be lagged to the slab with some elongated holes for wood movement. Did these first which was when I thought I should dovetail the sides as well.
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[Brian Holcombe]

Coming along nicely! Do you have plans to lift the base from the ground slightly? With small feet perhaps.

Nice work on the joinery especially.

[Zuye Zheng]

Have it built as initially planned, but will need to revisit the drawing board as I tried to defy physics and it didn't work out too well. The side leg needs to be thicker as it twists now when force is applied horizontally to the top. The diagonal support also should've been much thicker as it is currently quite springy. I plan on using some white oak to bolster both areas...

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Coming along nicely! Do you have plans to lift the base from the ground slightly? With small feet perhaps.

Nice work on the joinery especially.

Thanks! Yep, plan on some small feet screwed in that I can replace if rotted in the future.

[Stewie Simpson]

Zuye; the single diagonal brace currently supporting the weight of the table top is being held under tension; imo an inherent weakness within its design; you need to reverse that condition to allow the bracing to work under compression. The easiest way of achieving that condition is to modify the existing bracing to form an x pattern.

Stewie;

[Kees Heiden]

Nice work on the table top Zuye. And indeed I can see how the bracing needs extra attention. The X- idea is a good one.

[Pat Barry]

Have it built as initially planned, but will need to revisit the drawing board as I tried to defy physics and it didn't work out too well. The side leg needs to be thicker as it twists now when force is applied horizontally to the top. The diagonal support also should've been much thicker as it is currently quite springy. I plan on using some white oak to bolster both areas...

Hi Zuye, the top looks very nice. I do think the base looks, at least to me, undersized for the size of the slab. It seems it should have had a significantly longer bottom stretcher so that the cantilever on the laminated support side is reduced by at least 1/2 the overhang distance. The other end does need additional cross bracing as the angle of that support leg is a very weak one. I do not think that a X brace is going to do as much for you as it will not address the basic weakness of the design. I would add, at a minimum, two diagonal supports in opposition to it. One at the bottom that ties in to the stretcher and one at the top that ties in to the top stretcher. Even doing this the two table ends at this end of the table will be weak and prone to flexing. I see hat you were going for, but, I do think in retrospect that the base should be redesigned to be a more typical trestle table design. I

[Brian Holcombe]

Edit, I tend to agree with Pat, you're probably much better off building something with two large uprights and ditching the cantilever. That cantilever doesn't seem to appear in any of his dining tables that I have seen and I suspect there is a logic behind that.

[Prashun Patel]

Zuye-

Your design sense appeals to me.

Instead of scrapping the cantilever idea, can you just make the diagonal support a little closer to vertical? I think you can get the same visual effect (to my eye in fact a better effect) with a less drastically slanted leg. Also, I'd add cross supports along the top stretcher as in a Shaker trestle table.

[Stewie Simpson]

Brian; Zuye's design looks remarkably similar to some other Nakashima inspired work.

https://www.google.com.au/search?q=n...HVBQDmwQsAQIJQ

[Brian Holcombe]

I see that design used as a desk, but I don't see it as a dining table (it may exist as a dining table but I have not seen it). I suspect the thought behind that may include stability in use of multiple people, where a desk is typically used by one and not on the ends.

Also, you may note that when it's used as desk the wide portion of the upright is on the floor, not joined to the top. However, when used as dining table with two uprights the bottom is narrower than the top.

[Stewie Simpson]

Brian; this Nakashima inspired Dining Table ticks all the boxes for me. https://woodlandcreekfurniture.com/p...-dining-table/

[Stew Hagerty]

It looks to me like you were aiming for something like this desk of his:

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I like the design. So you just need to make a few changes to the geometry... It's cool looking.

[Adam Herman]

Could you post tension the diagonal support to the vertical slab to stiffen the structure? using 1/16 wire rope and a turn buckle or similar. this should take out some of the "spring" and relieve some of the bending stress on that member. I am thinking from the center of the diagonal to the point where the top meets the vertical.

[Zuye Zheng]

Thanks for the ideas guys, based the design off some of his coffee table and desk designs as Stew posted, guess it doesn't translate too easily to a larger dining table. My wife has began calling it the toothpick...

Before scraping the base, will try a couple more things to get the strength needed. For the toothpicky part, will be thickening it up lengthwise of the table with a tapered oak piece to also reduce the angle. Not sure if I should bolt it in or if glue will hold between the 2 species considering wood movement shouldn't be that great of a factor.

I'm also going to add another diagonal to form an unverted y to prevent sag, tried this out and it seemed to work pretty well.

Turning out out to be quite the Frankentable... Fun problems to solve though. Interesting idea about using wire though.

[Brian Holcombe]

Zuye,

Before you scrap anything, you may want to look at a style called the Minguren II, which IMO looks like yours might be able to be easily converted into that.