To make a beautiful end-grain coffee table out of a solid slice or “round” of a tree, it's best to start out with a log at least 20 inches in diameter and then cut out a cross section. It’s tricky process that we’re working to perfect at Treeboard, and here are the basic ten steps.
- Find a suitable tree. The tree needs to have a cross section that’s big enough for a table. We’ve been sawing away on a trunk with a diameter of 25 inches (64 cm) from an oak that fell naturally near our workshop.
- Saw off a disc, or “round.” Pretty straightforward, if you have a chain saw or band saw mill. We have experimented with different thicknesses and found that two inches (51 cm) is solid enough without being needlessly heavy.
- Dry the round. A very important step. We use a fan in the basement and allow many weeks to dry the wood to below 10% water content. The round will warp and crack while drying, and we’re experimenting with ways to minimize large cracks without applying chemicals (some woodworkers soak wood in petroleum-derived products to displace the water or stabilize the wood).
- Fill any large cracks. The round of wood inevitably stretches and cracks because the wood shrinks much more along its circumference than along the radius, effectively pulling the circle apart and leaving a missing "slice." We fill the largest cracks with inert epoxy resin.
- Flatten the wood by machine. Even if your chainsaw cuts were straight and parallel, the drying process involves warping. So Treeboard built a special jig to help with the labor-intensive process of flattening stubborn end-grain wood. We use an electric plunge-router and other tools with our jig.
- Hand-plane until it’s flat as a pancake. Nothing drives a woodworker or a customer as crazy as a noticeably jagged surface or a rocking piece of furniture (unless it's a cradle or rocking chair). So we use a Stanley No. 62 low-angle hand plane to complete the flattening process and remove the machine marks from the table top, working up a sweat in the process.
- Add the legs. Flat surfaces make it easier to attach legs of equal length and get a solid, level table. We’re currently using half-inch (13 mm) iron pipe and pipe fittings to make the sturdiest possible finished product. We favor made-in-America products but we found some of the Ward pipe fittings we used to attach the legs to the table weren't flat enough for our level so craftsmanship, so we're looking for alternatives. One thing we've learned is that having three rather than four legs eliminates the possibility of rocking. (If you have other ideas for table legs we’re happy to hear them or to read any other feedback submitted through our contact page.)
- Apply a natural finish. At Treeboard we're avoiding synthetic finishes, relying on natural oils to bring out the stunning look and feel of the tree without locking the grain behind a layer of plastic. We use food-grade boiled (polymerized) linseed oil, often called Danish oil, and we rub it into the grain by hand. Some of the oil actually flows through pores and cracks and comes out to the bottom, which is also rubbed with oil. Customers can renew the finish when needed with the free jar of oil included in each order. A bit of food-grade charcoal mixed with the oil brings out the grain, and the side of the table—a "live" edge of the sapwood—gets a little extra water-based stain for uniformity.
- Pack and prepare for shipping. The good news is that the coffee tables are rock solid and very unlikely to suffer damage during shipping and handling, which we're currently offering free of charge. Still, if there’s a problem, please let us know and we'll repair or replace the table.