Rehabilitation of a Precious Crest Rail

Quandary

On a good day, Vidar's Chair presents plenty of worthy challenges for the chair maker, but when the material keeps biting back, it can be especially challenging. After eight faithful attempts to make the crest rail for this white oak iteration of the chair, I was forced to contemplate its future.

I honestly believe that there is just too much that is good about this chair to switch materials at this point. Of course, I've considered the time invested so far, but I think also that there is an opportunity to successfully complete this chair without starting over. There is a lot of good wood in this chair and it's only the crest rail that has held us back. Let's take a closer look. Out of the eight attempts, seven of them exhibited checking. The one that did not was a mess of grain graphics; certainly not in keeping with the rest of the chair completed, so far. It's Number 4 from right in the photo above. You can see the asymmetrical wavy grain lines.

Decision

So, what to do... what to do? It's been decided to take the best candidate of the remaining seven and see what can be done to rehabilitate it into a beautiful, durable part. Number 2 from the right is my selection. This happens to be the one that had been taken the farthest distance in terms of joinery and shaping. That's the one consolation, I guess. It had shown no signs of checking when first cut from the plank, and has remained completely stable since the checking emerged about a week after being cut from the plank. As you can see below, Number 2, in the center of the photo, has beautiful grain lines that dutifully follow the shape of the part, just as Vidar had intended in his design.

Problem Defined

But, as we have seen, there are issues to be addressed. They occur at three locations on the chosen part as shown in the photo below. Fortunately, most of the checking is relegated to the bottom, leaving the top, front and one end completely check-free. The checks that occur on the bottom are near the back and in a couple of cases wrap around very slightly to the back side and one end.

The following is a series of close-up shots showing the checks prior to any restoration attempt. Below, you can see checking near the bottom rear edge of the left end.

Also, on the left end is a slight indication that the checking runs a little deeper. Check out the thin line of checking in the center of a ray just left of center in the photo below.

Here is a small check a few inches from the left end, on the bottom and extending slightly to the back side. The millimeter tick marks give a sense of scale of what we're looking at.

More evidence is found on the right end; mainly on the bottom and slightly on the back.

Ordinarily, checked parts like this find their way very quickly to the off-cut bin, however, the persistent occurance of checking that I've found in the white oak from 4 suppliers, representing 5 different trees has put us in a tough position. Seeing the incredible grain graphics available in Number 2 is what tipped the scales in favor of rehabilitation. There is some risk in doing this, for example, what if there is continued checking? What happens if a hidden check emerges at the surface some years later threatening the value the client sees in the chair? Studio Tupla warrants that the furniture is free from defects in material, etc., etc., but in this special case, the client has agreed to let me proceed with this plan. What I have promised in return is that if this chair presents any cause for disappointment due to future checking of the crest rail or any failure of the rehab, I will replace the entire chair with another made from a different, mutually agreeable species of wood.

I'm very confident in the solution I've chosen and am excited to begin the rehab.

Solution

Rehabilitation of this part will consist of the injection of low viscosity epoxy resin as deeply as possible into the checks. This will provide a substantial degree of stabilization and durability for the part. Below, you can see the plastic tip of a syringe going into the 0.070" diameter hole that was bored into the underside of the part on the right end. I then provided continuous pressurization to the epoxy by holding down the plunger at the same time I maintained a sealed condition around the hole. I held this pressure for several minutes as the epoxy resin seeped into the crevices. It was a very slow process for each location, but I was rewarded when I could see the liquid migrating out of the checks; even out of extensions of those check lines that were previously unseen through my bifocal glasses plus 4x Optivisor.

The same procedure was done at the left end. As you can see, most of the holes will be hidden after the crest rail is attached to the rear legs.

While in the situation shown below, the injection ports were located on the bottom which will require additional work to conceal.

The low viscosity epoxy requires a seven-day cure time which I was obliged to abide by. I then rounded up the off-cuts from Number 2 to locate material to hide the injection ports where needed. I selected the piece cut from the bottom of the crest rail.

And removed a small section adjacent to where the repair was needed.

Below is the prepared blank for the patch. This preparation ensures that the grain of the patch matches the grain of the crest rail very closely.

And here's the prepared crest rail, ready for the next step.

I honed a small gouge that I then used to scoop out the surface material at the holes.

Then, using the same gouge, I cut a patch, doing my best to match the grain pattern.

Glue was applied and the patch was clamped overnight.

Upon removal of the clamps and clamping caul, here's what I could see.

After shaping with the spokeshave, here's what it looks like with the camera lens approximately 3/4" from the patch. Note the slight darkening of the check line where it is now filled with epoxy.

Below is a second shot of the repair from about 5" away. The repair is about 1/3 of the way up from the bottom of the image near the right edge of the facing surface.

It would be an understatement to say that this chair will have a story attached to it, there is no doubt about that, but persevere we shall. I have a few more items to address with the other checked areas noted above, so off I go...

Hej då!

Craig