I've finally completed the tabletop for the desk I said I wanted to build from rough cut lumber back in
this post.
I planed the boards with a hand plane, getting the faces fairly flat, then ran them through the table saw with a jig to cut straight, square edges. Next, the boards were glued edge to edge, reinforced with dowels.
Once the slab was glued up, I made a router sled to get both sides of the tabletop perfectly flat. I don't have a photo of the router sled process, but in this shot you can see the flattened tabletop sitting on the router sled after flattening. Here, the tabletop is resting across two parallel rails. The router sled itself is in the background. It's a wooden tray that rides on the rails, with parallel sides that the router slips between. A slot down the middle of the sled allows the router bit to pass through. You set the depth of cut to the low spot on the slab and then work the router back and forth, skimming wood off the slab until the whole thing is flat.
To reinforce the top, I made a perimeter frame out of small diameter logs, with mortise and tenon joints holding them together. Once the glue was dry, the perimeter frame went onto the router sled to flatten the surface that would contact the tabletop. With the top of the frame flattened, I glued and dowelled the top to the frame.
The aspen tree this wood was cut from has been eaten in places by worms, leaving tunnels through the wood that generally run with the grain. Some of these were exposed on the boards and, rather than cut those sections away, I decided to fill them with clear acrylic so you can see the worm channels, while still having a flat, smooth top.
I then finished the top with 8 coats of lacquer, sprayed with an HVLP gun. Here is the tabletop, along with the four legs (set up in a drilled plank) right after spraying one of the coats.
After the last coat, I wet sanded to 2000 grit, polished with cutting polish and coated with a beeswax finish. The finish is smooth as glass.
Some of the wood has very pretty, fiery grain.
It turns out that I didn't bring home quite enough wood to finish the table when I harvested it in the fall. The next time I'm in the mountains, I'll need to bring back one more small log to make the cross braces to connect the front legs to the back. Everything else is ready to go. It'll probably be sometime in April before I can get those last sticks and complete this thing.