Here are the steps I followed for fuming the clock. “Pay attention, this is a tricky”, I say with a sarcastic tone in my voice.
You’ll need a large container. I opted for a clear plastic tote, but you can build a tent from sticks and visqueen if you prefer or if you decide to use this technique on other, larger projects. Seal any openings before moving on. This process is called fuming due to the ammonia fumes reacting with the tannin in the oak. Any introduction of outside air could weaken the solution and retard the fuming.
To begin, position your clock off the bottom of the tote with a couple sticks, then slide the door and back into the tote as well. It’s OK to lean the extra pieces against the clock, but make as little contact as possible so you don’t affect the reaction. Next, pour some ammonia into a plastic dish. We used about a 1/4” of ammonia in a 4-1/2” diameter dish. (Not really a great amount of ammonia, huh?) Place the dish inside your container, clamp the lid in place and let it cook.
On a serious note: This ammonia is dangerous to your eyes and lungs. Be careful and wear protective gear such as eyeglasses or goggles, some type of gloves to protect your hands and an appropriate mask. I can speak from experience. Not being the sharpest chisel in the cabinet, I wanted to experience this awful smell first hand. I did and it damn near knocked me to my knees. I do not wish to experience this again! I suggest you not experience it either.
As I watched the tote most of the afternoon, I noticed that the door and back were gaining a dark color quickly while the main clock was slower to react. It seems that within a species, different woods react differently when fuming. That’s exactly what happens when using other finish methods and it’s why you should try to use wood from the same tree – known as matched sets – when building projects.
Bob suggested that I pull the door and back from the tote and allow the clock to fume overnight. Careful does it when removing the lid from an active fuming process. Again, the fumes can be overpowering. A friend’s help is important so you can pull the pieces but continue to keep fumes enclosed.
The next morning was like opening a present. I carefully pulled the lid off the tote and allowed any residual fumes to escape into the air. My ammonia solution was all but water at that point. Once it was safe, I reached into the tote and removed the clock. Interestingly, all the pieces, those pulled the day before and those revealed that day, were very close in shade.
I allowed the project to sit for a couple hours until the ammonia smell diluted, then lightly sanded the project with #400- grit sandpaper and a gray abrasive pad. I had an area along one edge that was lighter in color – I had seen the difference earlier as I built the clock, but failed to remember to orient the piece toward the rear of the clock as I cut the groove for the back.
After I ragged-on a single coat of amber shellac and lightly sanded the project, I used a medium fumed oak aniline dye to pull the lighter color more in line with the darker fumed color. A couple layers of dye skillfully applied with a cloth did the trick. I then let that added color dry.
I followed with another coat of ragged-on amber shellac. When the shellac was dry, I lightly sanded again with the #400-grit paper, then added a protective layer of paste wax.
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