"Turning Wood into Art"

"Nothing is better for a man than that he should eat and drink,
and that his soul should enjoy good in his labor...."
-Ecclesiastes 2, 24

Thursday, January 21, 2010

From Tree to Table Part 3, Finish turning

Having spent the last week building and publishing my new website, which I hope you've had a chance to look at, I'm running a bit late on this series.  With that said: let's fast-forward 6 - 12 months from where we left off in Part 2.  Our rough-turned bowl is now dry and ready for finish-turning to complete our project.

But first let's look at our rough bowl.  It's certainly very different from when it came off the lathe so many months ago!  In fact it's barely recognizable!  It's warped, twisted, gone oval and done other weird things - all of which need to be fixed before our bowl can be used or sold.

Our first task is to re-mount the bowl on the lathe.  We also bring-up the tailstock to ensure that our bowl doesn't become an "unguided missile" as soon as we make the first cut. (Which can be a little hard on the bowl - not to mention anything (or anyone) that/who happens to be in its path!)

As before, we rotate the bowl through a full 360 degrees to make sure everything is clear- and that nothing untoward will happen when we start turning. We can now power-up the lathe and adjust the speed so that everything's running smoothly.

Using our bowl gouge, our first cuts true-up the rim.  Next, we true-up the exterior and establish its final shape. Then starting at the top/rim, we work our bowl gouge down toward the base.  It takes several passes, but the outside is now round and we're happy with it.   A couple more light scraping passes and the outside is smooth and ready for sanding.  This we do starting with 150 - 180 grit and proceed through 400 grit sandpaper.

We next re-sharpen our bowl gouge to ensure clean cuts, remove the tailstock and start our "inside" work.

As before, we work our bowl gouge from top to bottom to establish a clean, round surface.  With that done, we cut a slight bevel into the rim and then slightly undercut the rim.  This gives a good firm place to grip and makes carrying the bowl much easier - especially when it's full!  Continuing our undercut, we want the thinest point of the bowl about 1/4 - 1/3 of the way down, then gradually increase the wall thickness so as to lower the center of gravity ensuring a stable vessel. Again, we sand down through 400 grit and create a smooth interior surface.

Now, borrowing technique from old-time gunsmiths who needed a glass-smooth finish on their gunstocks, we spray the entire bowl with a light coating of water to raise the grain.  We sand off the raised grain with 400-grit paper and repeat the process 2 - 3 times - or until the grain no longer raises when wet.  We can now move on to 3 grades of non-woven abrasive pads (think nylon scouring pads on steroids!), which remove the last of the micro-scratches and burnish the wood to a soft satin luster.

We now reverse the bowl on the lathe and finish the foot/base. Our bowl is ALMOST done!  We can now sign and date the finished bowl and note the wood specie for posterity.  The final step is to soak our finished bowl in pure walnut oil, which penetrates the wood, then hardens (polymerizes) to form a durable, food-safe finish.

After soaking for a couple hours (or overnight), we remove it from its walnut oil bath, wipe off the excess, and set it aside in a warm space for a few days to allow the oil to polymerize.  At the end, we have a piece that, with reasonable care will last for generations! (Good thing given the amount of time and effort we've invested!)

I hope you've enjoyed this series so far.  Please feel free to add any comments.

Next time, we'll look at turning a "green" bowl to completion and finally delve into the history of bowl turning.   Until then...

P.S. Blatant Commercial Plug: You can easily get past all the work described above by buying a finely crafted bowl from me.  Check out my website link on this post!

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