Leaps and Bounds
At long last, my coffee table project is progressing quickly. (About time I can almost hear some of you thinking.) After working through many details with my scale model, I got busy cutting the parts to size. It felt good to be making sawdust at full speed.
After cutting the base parts to length and width and detailing the ends of the cross pieces of the undercarriage, the next details included drilling dowel holes and sanding all the parts up to 120-grit. With that all done I did a dry assembly without glue. All the pieces fit together properly, and the exercise let me figure out a workable assembly routine.
Once the base was glued up and in clamps, I carried the subassembly inside my house (warmer temperatures help glue to cure). At that point I moved on to making foot pads for the base. I had some cut off sections of the bubinga which I ripped to width and then resawed to 3/8” thick. I cut them off at 3-½" and mitered all four corners of each pad. I liked the idea of the bubinga pads just peeking out from under the cherry base. I glued the pads in place and set it aside for now.
It was time to sand the tabletop smooth and prepare it for a finish. There were a few spots on the top where saw marks remained. To deal with those I grabbed my 4 x 24 belt sander outfitted with an 80-grit belt. I primarily sanded across the grain as I worked to remove the saw marks and get a uniform surface. I use a low raking light when sanding. It reveals the sanding marks and other flaws allowing me to deal with them.
With the belt sanding done, I grabbed my RO sander and starting again with 80-grit and proceeded to sand the surface and the edges up through 320-grit. I carefully broke the edges of the tabletop, rounding the edges just a small amount. I used a new 3M sandpaper for this task and was super impressed with its performance and durability. I’ll do another blog post on the sanding disks when I know more about them.
With the surface repaired I applied a coat of linseed oil thinned slightly with turpentine. And even though this was not my first rodeo, the way the figure in the wood popped when I wiped on the oil got me really excited. (See the video below.)
I set the tabletop aside and got to work doing a final sanding on the base. I sanded it up through 220-grit, finding a couple of glue spots on the way. I cleaned those up and completed sanding. I put a coat of the same linseed oil mixture on the base. Now it is a waiting game until I apply the next coats of finish.
My game plan for the finish is as follows. Once the linseed oil has cured sufficiently, I will apply several coats of shellac. That will let me build up a sturdy film coat quickly. I will de-nib as needed during the process. I am guessing about four coats of shellac. Then I will hand sand all the surfaces with 400-grit sandpaper, wipe away the residue and apply two coats of wipe-on polyurethane with a medium gloss. Let that cure and the table will be ready to use.
Here is my rationale for that sequence: linseed oil to pop the grain and seal the wood. Shellac to build up a tough film coat quickly. But the shellac will be too shiny for my taste and also degrades with alcohol, so I will finish with the polyurethane to add durability and bring down the gloss. I am wiping it on to avoid any possible drips.
