How I Prepare Bowl Blanks

by Abe Sloan

In the beginning I used 2”x 2” x 12” pieces to practice making beads and coves using dry lumber. Many hours. Beads and coves. This was a good way to start because square lumber is easy to use and relatively safe to mount on the lathe. Instruction on getting started can be found in many books, video tapes, and DVD’s.

I started with the VHS “TURNING WOOD” by Richard Raffan. My favorite books are by Mike Darlow. His approach is very clear and thorough.

These days, I make mostly bowls and start with fresh cut logs.

There are advantages to using green wood.

· It is available

· It is free

· and it is easier to turn than after it dries.

Here in Florida the spring storms and late summer hurricanes leave plenty of raw materials to work with. You might have to be a little creative in your area if you do not have our natural advantages.

You might try the local landfill, or a tree service, or some other source. When people learn what you are doing, they will tell you about available wood and may even bring it to you.

Just last week a man I did not know showed up in my driveway with a pick-up truck full of red cedar. He was a friend of the electrician’s helper who had done some work for me a month earlier. Free and delivered. Can’t beat that.

I always give wood donors a finished piece of their wood. It makes them feel good and it helps them remember you when they see something you might use. I find his also leads to sales.

Green wood presents two problems that must be dealt with:

· checking (cracking) · and warping

I start dealing with checking when I first come into contact with a log by noting any small cracks I can see in the ends. If there are too many or they are too big I move on.

When a log shows promise I cut it into pieces as long as I can handle, but always longer than the diameter, and take it home. At home I paint the ends with a green wood sealer and stack it up off the ground in a dry, cool, shady place. There it will sit and I will get back to it as quickly as possible.

When I’m ready to start a bowl I again inspect the end of the log I will cut from for checks. If a major crack has appeared I cut away an inch or two to get past it.

Then on the fresh end I use a magic marker and draw a straight line to mark the cut through the pith along the path of the checks to eliminate any unseen continuation.

If there are other cracks radiating from the center I might cut away more of the pith with the chain saw, or I might wait and deal with it later on the lathe, or I might move on to another piece of wood.

If I see a check that is not radiating out from the center I immediately put that piece and the log it came from on my neighbor’s firewood pile.

That helps to keep wayward chunks from flying around the shop. And since such cracks may not be visible I use a face shield which is long enough protect my neck from these missiles because I have heard some pretty gory stories about splinters in the eyes and neck.

The final step before mounting the half log on the lathe is to make it round. Some (maybe most) turners use a band saw for this. I don’t because I could not afford a band saw large enough to do what I wanted.

I use the chain saw and round plywood templates. I nail (actually I use an awl because it’s easier) a hole in the center of the template and into the centerline of the flat side of the log. Then I cut off the corners that extend outside the template until the piece is nearly round, remove the template, and drill a mounting hole for a screw chuck in the nail mark.

At the lathe I rough out the bowl with two things in mind.

· First, to make the wall thickness equal to about 10% of the diameter of the bowl.

· Second, keep the wall thickness as even as I can top to bottom which helps reduce later checking.

These are guidelines, not rules. You will need to provide for a way to re-chuck to do the inside of the bowl, and that will require an adjustment in thickness. So will the final design of the bowl, but that will be done during the final turning. That will be done months or even a year form now.

All wood has internal stresses while drying which will cause it to warp. Warping can result in checks if care is not taken. This is because the inner layers and the outer layers do not dry and shrink at the same rate.

In general thicker walls are more inclined to crack while thinner walls tend to warp more. The game is to strike a reasonable compromise. Part of the compromise is to make the walls thick enough that after warping there is enough wood left to re-turn the piece to round. And all depends, in part, on the type of wood you are using. Some species are more stable than others. But regardless of species, the problem that needs to be solved is how to get the inner and outer layers to dry at more nearly the same rate.

This problem of ‘even drying’ has been approached in several ways.

Some turners start thin. They turn their green pieces so thin that they will warp but not crack. The result is one-of-a- kind free form pieces.

Others make natural edged pieces where perfect roundness is not expected. The drying process is relatively short and in my climate requires only a few weeks in brown paper bag before sanding.

Still others use microwave to aid drying and end up with translucent free forms (someone else will have to tell you how). All can have excellent results. Starting with thin walls makes it possible for the wall to dry a more uniform rate.

Some turners soak their roughed out pieces in soapy water. They say that it reduces cracking and makes turning easier. I tried it and found little difference between that and the method I was using at the time which was to store the rough pieces in brown paper bags and hope for the best. I lost about 15% with either method. Oh, I almost forgot. After a few days of soaking the soapy water began to smell pretty bad, probably due to our Florida climate. A little alcohol (in the water) did not help much. So I don’t do that any more.

One turner here in my neighborhood boiled his rough outs. He had a big iron pot in his back yard over a stone and brick fire pit. He used stones or bricks to weigh down the bowls and fished them out after they had cooled. He then wrapped each piece in newspaper held by masking tape and stored them in a closet. He showed me some of his bowls that were drying. I noted that my bowl in a bag method was doing about as well as his boiled in a pot system, so I never tried it. But some turners swear by that method.

My current method for drying roughed out bowls is to paint them thoroughly inside and out with green wood sealer.

Drying takes four months or more to complete, depending on thickness. That is quite a long time, but I have had very good luck with cracking using this method. I always try to rush this process and end up with bowls that warp after I have done the final cuts.

So now my finishing cuts are a two-step process. The first step is to take out the warp and give the bowl a hint of its final shape. Then I set it aside for at least a week and see if it warps some more. If it does, I repeat this step as often as necessary. If not, I do the final shaping and finishing.

My friend J. Sullivan is all excited about a drying method that starts by soaking roughed out pieces in alcohol. He says drying time can be reduced from more than six months down to two months. That would be great if it works. That would mean that you would need a lot fewer bowls drying, and that would require a lot less space. That’s if it works. I’ll let you know.

About the Author

Abe Sloan is an avid wood turner currently living in Gainesville, Florida. He loves to exchange ideas and tips with other wood turners and also enjoys collaborating with anyone who like beautiful wood. http://www.AbeSloan.com

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