A Minor Project

I’m finally completed some work that was under a N.D. Agreement, so I can return to regular programming, blog-wise. Look for another post in the Dark Chocolate and Sponge Cake series soon!

Meanwhile, I can talk about a small project I tackled over the last couple of afternoons in my frozen cold shop: a wooden serving tray. Maybe it is hardly worth writing about, given that it took less than 6 hours to put together, but it did allow me to explore some fun joinery that came as a result of considering various options for connecting some sort of feet to the tray top.

I’ve made many sushi geta previously, which are simple wooden tops with transverse battens, held in to the top with full length sliding dovetails, and serving as feet. If you google the term you’ll see what I’m talking about.

The issue with that sort of construction, even with a top as narrow as 6″ (155mm) across, is that seasonal movement in the top across its width will leave the end of the dovetailed battens either protruding or slightly recessed at different times of the year. It’s no big deal, considering what they are used for, but it is nonetheless a drawback to that form of connection. The exposed dovetail joint is also a decorative feature on the geta, a sort of message most people will get, if that’s going to be part of it, design-wise. If you’re not interested in such messages, then it’s a drawback to have the joint exposed.

Also, while a flat-bottomed batten is a relatively simple thing to produce, in order to have a piece that will be less prone to rocking from bottom surfaces that are not co-planar, or are bowed slightly by movement of the top, one might resort to hollowing out a mid-portion of the batten undersurfaces to produce, in effect, a pair of ‘feet’ at either end. This is what I’ve been doing anyhow, and on recent pieces I’ve taken to more deeply machining out a hollow in the bottom surface which leaves much more pronounced 2-footed look.

With a wider top board, even if one were to employ quartersawn material, the dimensional difference between the width of the top (which shrinks and swells) and the length of the battens (which hardly change length at all) would be evident at both the driest and the wettest time of year, so it is an even less ideal solution when you get into wider tops.

And if you’re going to shape a batten’s undersurface to produce 2 contact points widely apart, then you’re well on your way to another form of feet for the tray altogether, one consisting of 4 separate feet instead of 2 battens. That way the feet can float back and forth with the movement of the top board. The batten doesn’t serve much purpose besides that of a foot in a sushi-geta, so though simple, I thought more about having 4 independent feet on the tray.

Along those lines, I considered different ways one could connect those feet to the top. There are plenty of options, and in thinking about placing feet so that they meet the perimeter of the top in some locations, one consideration that came to mind was thinking ahead as far as the chamfering is concerned. It’s an issue with the regular exposed end of the sliding dovetail batten form of construction – it is a joint interface which doesn’t lend itself well to chamfering unless you also partially house the batten sidewalls into the surface.

So, with those considerations in mind, this is the solution I decided to explore, by all means not the only one, but one which I think may have a certain usefulness. Here’s an overview of the connection, assembled:

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I’m fortunate to have an off-cut chunk of quartersawn Honduran mahogany kicking around, and that seemed like a good piece with which to make a large serving tray. In preparation for the layout and joinery, I leveled the bottom surface of the board:

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Despite a clean appearance, the board had a 3″ (76mm) long slightly scalloped band in the surface, which you can faintly see in the above photo after the first round of passes, and there was no point taking many shavings to get rid of that dip when just 3~4 heavier passes, one of which you see above, did the job. Obtaining a clean, tool mark-free surface is the goal regardless of how many passes one takes, and that was managed somehow.

Then, entirely on the mill, using a sequence of cutters and operations, I produced some double-dovetailed sliding trenches at four points:

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A closer look reveals the double dovetail trench:

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Then some chisel work followed to clean up the interior abutment:

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A small block of tight-grained cocobolo, 4″ (105mm) square and 1.25″ (30mm) thick provided enough for the four feet:

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As the run of the grain is aligned between the top and the sliding dovetailed feet, I could have glued without the usual concern for seasonal movement working over time against the connection. But instead I decided to do the connections dry, using just the friction of fit between the parts, and trust that to hold up over time:

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This piece will be in use in our home, so I can observe how this dry fit joinery approach plays out over the years. I’m not much concerned though, as I’ve plenty of other pieces with dry-fitted joinery in my living room and they’re doing fine.

Besides, cocobolo, being an oily wood, is tough to glue and my strong preference for that task would be to employ a special epoxy that I have for oily woods. While mixing a bit of glue is no big deal, after a brief mulling over I concluded ‘some other time perhaps’ for that way of doing things. Let’s try an alternative route.

The foot starts its journey, a hand press-in to start:

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Then a mallet does the persuasion:

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I know there should be final ‘all the way in’ pic inserted here, but I forgot about taking a picture, so…

…and there we have it, four feet fitted:

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I applied some wax, which brings out the cocobolo especially:

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One can apprehend other uses for this sort of connection, when one sees the parts in the above orientation.

The chamfer follows a pleasing jog around the foot:

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A view of the underside – the ends of the feet overlap the ends of their mortises by 1/4″ (6mm):

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Before the top and feet were brought together, I did give the top and all edges a finish planing, so once the wax is rubbed out the piece will be done:

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That’s our new tray, and has taken up residence inside the dining room cabinet. I look forward to using it.

Thanks for tuning in, and hope to see you next time.