Finishing Wood

Finishing is not one of my strong points, although I have tried several different products and also have read numerous articles and books on the topic. It seems that my finishing techniques are constantly changing. When I was an apprentice in my early twenties I was taught to use General's tung oil finish applied with a sponge brush and then wiped off if there was any finish left on the surface after twenty or thirty minutes.

Soaking with tung oil/urethane.

Then water based finishes starting to emerge so I began experimenting with those. I didn't like how you couldn't go back over what you had already brushed on, I was used to applying the finish heavily and then going back over it with the brush to even it out. I remember using water based urethane on a set of nine sliding doors for a house in Oregon. I am sure that this finish didn't hold up because a decade later I went back to using water based finishes and noticed that the finish didn't seem to stay on the wood for very long at all. It was almost as if the finish itself just evaporated away. I discovered this by using it on three different kitchen cabinet projects and seeing for myself how what seemed like a well covered finish when the cabinets left the shop, only a month later seeming like raw wood with no protection at all.

I read a book given to me by Alex Cockburn called Adventures in Wood Finishing : 88 Rue de Charonne by George Frank,  about a French chemist who worked as a wood finisher in the early 1900's. He made his own finishes and being a chemist experimented with many different chemicals. I followed this path for a bit making my own linseed oil mix and even using a double boiler to make a wax and oil finish. Sam Maloof also talks about concocting finishes this way in his book Sam Maloof, Woodworker. It was messy process and the finish took a long time to dry.

I discovered how to make my own shellac when I took some summer classes in Fort Bragg at the fine woodworking program started by James Krenov. I bought shellac flakes and had a concentrate that I would thin and apply with a rag. I did this for a few projects but the super thin coats took too long to build up and I longed for something more durable, long lasting and non-toxic. I used fast drying polyurethane for a bit but the toxic fumes were unbearable. I tried spar varnish but it seemed impossible not to have drips.

I went back to using water based finishes after our neighbors used a w.b. finish on their floor in their newly constructed cabin. I liked that it didn't have a particularly bad smell and it dried really fast. I got used to just going over the wood once without doubling over what I had already applied until after it had dried and was sanded. This is when I used water based urethane for the three different kitchen projects I already mentioned.

Finishing carcass parts before assembling.

I decided to try something new, I browsed the finishes at Pierson's Building Center, our local hardware store. I started using a penetrating tung oil by Deft. I really liked how the finish soaked into the wood and the smell was much better than Watco's oil finish. The only thing I didn't like was how it took so many coats to build up the finish.

A woodworking friend told me that he had read an article about someone who used the pre-mixed shellac by Zinsser, by cutting it one to one with denatured alcohol. I decided to try this out since I felt I still had not discovered the ideal finish for my work. I liked this very much, it dried fast, left a solid finish after two coats on wood and smelled good. I started using it on everything, however my wife felt that it might not last and needed to be more durable especially for outdoor applications like windows and doors.

Thinking back to all the articles and books I had read I decided to add the penetrating tung oil to the wood that was first sealed with two coats of shellac. This is what I do now, what a beautiful result! Of course there is more to finishing that just applying the product, there is sanding. Who likes to sand? I like to sand as little as possible, it is just another particle that could damage my lungs.

Redwood Door finished with two coats of shellac and two coats of Deft Oil.

Before applying the first coat of shellac I sand to 150 grit, if it is plywood I only sand once with 150 on an orbital sander. If it is wood I will start with 80, then 100, then 150 grit. Apply the first coat of shellac with a sponge brush, it dries fast and raises the grain. Then sand with 220 grit with a palm sander, hitting the corners and edges by hand. Apply the second coat of shellac. Then sand with 320 grit with the palm sander and this is the last time I need to sand. With a sponge brush I apply a liberal amount of Deft penetrating oil, let it sit for 20 to 30 minutes and use blue paper towels to wipe it down. One (or better two) days later I rub the wood with fine steel wool and use an air compressor to blow away the steel wool particles as I wipe it with a cotton rag. I apply one more coat of the Deft oil, wipe it off after 30 minutes, a day or two later rub it down with steel wool again and buff it with a cotton rag. The result is stunning. For plywood carcasses I only use shellac and four coats are applied.