Research on Waterproofing Wooden Furniture

I'm working on a pair of knock-down benches on a design by my friend Sean. These are being built with the ash I purchased last fall. I've finished gluing up the tops in one big panel that will be ripped down for two bench tops and one or two stretchers (as yet to be determined) Once the cutting gets under way, these should come together in under a day.

Since the benches are intended as camping equipment, and last year's two-week camping trip included 6 consecutive days of rain, I need to waterproof these appropriately. Some quick research turned up a couple sources.

First, from the U.S. Government, I found a short piece on finishing wood for outdoor use. This one sticks with traditional Big Box finishes—paints, stains, and varnishes—rating them on appropriate use. This gave me some thought: did I want to paint the benches, as this article suggested. Not really. And Ash wasn't on the list of recommended outdoor woods. Hmm.

So I started thinking about wooden boats, and my trip to Mystic Seaport last year. What would a boat builder do? Assuming that a boat builder would use ash in the first place. I turned up two more sites of interest: one about spar varnish and the other about a homemade polymer coating. As intriguing as the homemade option is, I think I'm planning to track down some spar varnish. I found three brands that seemed promising: Sutherland Welles, Man O'War, and Z Spar. I think one of these will end up on the benches.

If anyone has suggestions or cautions on finishing these benches correctly, please chime in.

The Promise of Pinch Dogs

This week I conducted a quick experiment: I jointed a couple of warped scrap bits to see how the pinch dogs I received last Christmas would work. The first thing I learned is that pinch dogs want roughly even surfaces: I knew they could go around corners (for mitered joints or more difficult multi-angle glue-up), but it didn't seem likely that they would work on the ends if the surfaces were not relatively coplanar.

Out came the hand saw (it was late and children were sleeping) and I cut down the longer board to roughly the same length as the shorter board. Then I smeared both edges with glue and started pounding in pinch dogs.

Thats when I learned that this tool could benefit from a little help when being applied. I would have liked to have a couple straight pieces of wood clamped together on each end of the work piece to keep the boards in the same plane. It also would have worked better if the boards were lightly held in place on the bench and had not been cupped (and therefore more like a rocker than a pedestal).

Even with these challenges, I managed to clamp the boards using these glorified staples, and set the assembly aside to dry. That was Monday night. When I came back to it this evening, I set it on the bench and it looked like the picture at the top of the page. The joint looked tight in spite of the trouble I had during glue up, but the rough cut surfaces and misaligned edges could be hiding the reality.

To get a closer look at the joint, I planed the surface down until the joint was revealed. Sure enough, the pinch dogs had done their job and held the joint tight. If you look closely at the picture below, you might see the joint, but it is tightly glued. The holes are visible where two pinch dogs held the joint together on the surface, but there will be many projects where that holes like that will be concealed. I expect to use these for the bench project I'm working on now: the holes won't be visible on the underside of the benches, and I've rough cut the stock long enough that I can trim off the ends after glue up.

Pile of Boxes and Warping Lid

I went to an event that had a marvelous door prize: 18 boxes made by my friend Sean. These were intended as prizes for a tournament, but there were only 23 entrants total, so almost everyone went home with a box. These boxes were made from some of the ash purchased at the same time as my stock pile.

As a member of one of the tournament teams, I came home with one of these boxes. It sat in my front hallway for the last four days, looking pretty. But now that the heat and humidity have returned to normal levels, the lid and front side are starting to cup away from the box. In part, I think this is a case of grain orientation; in part, a case of excessive moisture. I've taken the box into the basement and lightly misted it with water on the cupped sides. I've also cracked the lid to get the inside drying faster. I don't know if either of these actions will help, but it's worth a try.

Now I'm worrying about the benches I'm making, and hoping that the better treatment of my lumber (painted ends and tarp over top) will mean less moisture content. I did some research to see if you can figure moisture content without a meter, and found a method for calculating moisture content with an oven and a scale.

Perhaps I'll try it before building my benches.

Bench for the Radial Arm Saw

Soon I will have the table mounted back on the Radial Arm Saw, which for now is the only stationary saw in my shop. Once it is mounted, I'm going to build a new bench for it that does not wobble and places it at the same hieght as the workbench it sits next to. I'm thinking I'll build it like the low cost benches being built by Robert Lang, at Popular Woodworking.