Tuesday, February 2, 2010

Where Tung Oil Shines

Yep, it's February, let the tough times begin. This time always begins the long slog until the end of winter, which, to me, is the start of syrup season.

I couldn't resist digging through the photos that I took last year and putting this one up as my desktop. Sue and I literally laughed with glee when we saw it on the screen.

I recently read an interesting post that Kari over at the Village Carpenter wrote about finishing. She addresses a number of different finish options for one of her projects and the conclusion put Tung oil at the rear of the pack. It got me thinking, because for a very specific application, I love the stuff.

When I started making chairs without painting them, I had all sorts of trouble keeping the parts clean. In chairmaking, there is a lot of part wrestling and once a little dirty oil gets on cherry, you're sunk. Plus, because I don't sand my turnings, I couldn't just sand away the offending smudges. So I started applying a coat of finish right on the lathe.

First, I used my normal varnish mix, which worked fine. But then I remembered that I had some pure raw Tung oil from the Real Milk Paint Company. I bought the stuff because it's completely nontoxic, no metallic dryers or spirits. It smells great, but to finish a chair with it would be a chore, because it doesn't build a film without rubbing and rubbing and rubbing.

Here's where the lathe comes in. By applying the oil to the spinning piece and then holding a cloth on it until I feel the heat (should I be worried about exploding?!), the oil builds a lovely finish that I'm able to keep clean for the rest of the process.

I'm no finishing expert, but I think that the heat helps the oil polymerize (which I believe is the job of the metallic dryers normally in boiled linseed oil and hardware store tung oil) and build a quicker, tougher finish.

As you can see below, the finish is lovely and highlights the woods natural character. I do still add more coats of oil/varnish when I finish the assembled chair, but it seems like it takes about 3 applications before the other chair parts catch up with the turnings.

It's even inspired me to dig out my old can of Tried and True non toxic Varnish oil finish to try on my chairs. I know that the rubbing is added labor, but on a well prepared surface, it's like a victory lap. Plus, I'd love to cut my exposure to the nasty stuff in the spar varnish as much as possible.

By the way, Kari, great post!


Kari Hultman said...

Peter, I should have added a disclaimer to my post that said I realize that in the right hands, tung oil works beautifully! ; ) I'm a terrible finisher and am always so impressed with people who can get a piece of wood to look like you can.

Love the landscape shots! :o)

Peter Galbert said...

believe me, finishing is still the hardest part, the only trick I know is to not be surprised at how much effort it usually takes!

想想 said...


Premodern Bloke said...

Why do you not sand on the lathe?

Peter Galbert said...

I prefer to finish all of my turnings with a skew chisel, after which, sanding isn't necessary. Early in my turning experience, I decided to forgo sandpaper, which made learning the skew a necessity. I tend to think that it helped me become proficient with the skew, albeit with a somewhat brutal learning curve. It's a personal choice that keeps the lathe work lively and challenging.

greg said...

Victory lap!! I can't believe you said that. I love your finishes, and now I know why. Attitude.

I really need to get better at finishing. My problem is I hate, hate, hate it! I have 4 chairs I've made over the past year that are bare, and one that has been sitting around for 4 years waiting for the second through final coats. I need to do some radical inner Zen thing or my chairs are doomed.

Peter Galbert said...

I think that finishing is horribly misnamed, it should definitely be called "beginning", or at least "avoiding". It's always tough that the make or break for a piece comes during the part of the process that is beyond all the fun stuff. But that being said, there are no excuses for naked chairs!