Friday, June 26, 2009

Coffee table, day one.

So, I'm still waiting to hear back from a client about choosing a final design for a project, so I took this afternoon to work on a coffee table for my house.

The slab is a piece of English brown oak I bought a couple of years ago in Pennsylvania, shortly after I left school. It's gorgeous, and perfectly quarter-sawn, but the problem is that it's the exact center of the tree, dead center.

For those that don't know much about wood, I'll explain a few things.

Quarter-sawn means the board is cut radially from the center of the tree, so that the growth rings are running perpendicular to the board. This minimizes wood movement, so warping isn't as much of an issue. It also reveals the medullary rays of the tree, which are cells running radially out from the center of the tree. In the picture at left, they appear on the sides of the photo. For the tree, they transport water and other things between rings, moving minerals and other things into the inner layers. For furniture, well, they look pretty cool. Oak in particular has some spectacular medullary rays, which is one of the reasons that quarter-sawn oak figured so prominently in furniture from the arts and crafts period. Stickley furniture in particular used a lot of quarter-sawn oak.

The pith of the tree is the exact center of the trunk. Typically, it's very unstable, and prone to splitting. And, sure enough, as you can see in the picture, it did. When I bought the board, this had already happened, but the rest of the board promised to be really, really gorgeous, so I bought it anyway. And sure enough, when I splashed it with some water, the real colors came out. But so did some of the issues.

The rest of the pictures show me going thorough the process of figuring out where I wanted to put in wooden dovetailed "butterfly" joints to hold the slab together as a table top, cutting mortises, and inserting the butterfies. At that point, it was time to go home. But this is just the start of what will clearly be a pretty cool looking table, so I'm sure there will be more to come about this in the future.

Apologies about all the text squished into the sides. Next time I'll do a better job of organizing this.

Luckily for me, the split down the middle was pretty straight- forward. It was more or less continuous for the length of the board, and it was pretty clear that the two halves would come apart pretty easily.

The wood is still wet in this photo, but this is a good approximation of what the final color will look like... this table is going to look really good.

There were a few parts I had to saw through to separate the two halves, but they came apart pretty cleanly.

I used a jigsaw to make the cuts. But I had to loosen the base to let the saw tilt back and forth, because the orientation of the crack changed along the length of the board.

Inside the crack, things were a little gross. Some of the wood had either rotted, or gotten some kind of fungus. I'm not sure which.

I was able to scrape out the gunk and softer spots with a small drawknife and a couple of card scrapers.

Once everything had been cleaned up, the resulting gap is a little wider, anda little uneven, but very organic looking. Honestly, I wasn't sure how it would look, but it looks pretty cool.

It's funny... sometimes working with the wood, and allowing it to dictate some of the form makes the work easier, and helps make the final product look a little more interesting.

I used colored paper (actually, pink post-its) to cut different sized and shaped butterflies. these are the ones I settled on.

The butterflies have to be pretty thick, since they're going to provide some rigidity across the gap. The top will also be supported from underneath, but this ensures that the top itself still acts as a solid piece.

Originally, I tried cutting them out of the scraps left over from trimming the board down, but those scraps were full of cracks, and they didn't look like they'd hold up very well. So these ones are cut from quarter-sawn white oak.

Butterflies mortised into place. I haven't glued anything up yet, because I want to fine tune one of the butterflies. It's easy to lay things out and get them to fit in tightly as individuals. But one of them doesn't fit quite right when everything is together, so I may have to cut a new one to make it fit.

One more shot. This one gives a better idea of what the gap looks like.

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