spin dry?

[Tim Hoyt]

I recently got a load of sycamore. What a great wood to turn! Tools nicely and looks great! But boy oh boy is it wet. I seriously thought about wearing rain gear while turning. The only wood I have turned that was that wet was Buckeye. When turning at maybe 500 to 800 rpm I threw water about 10 feet.
While I was fooling around with the sycamore I got to thinking (danger, danger!)why not get rid of some of the moisture fast. I left a rough turned bowl spinning for a few minutes. Soon no more water was being spit out. All I had to do was increase the RPMs slightly to start the whole cycle of water spraying over again.
I suspect this will speed up the drying times a good bit. But like my wife says, some of my "good ideas" aren't so good.
So what's the down side of spinning some of the moisture out of wood?
Thanks

[Roger Chandler]

Accelerated warping, could lose enough moisture to cause the tenon to warp, sending the bowl flying into your face or across the shop....making a mess all over the shop, and with sycamore, be careful of wind shake. I had a chunk of a heavy sycamore blank fly off when turning and hit me square in the face shield. I was so glad I had on my Trend Airshield Pro! That chunk weighed nearly 3 lbs. and that was not a pleasant experience back a few years ago!

[John K Jordan]

I recently got a load of sycamore. What a great wood to turn! Tools nicely and looks great! But boy oh boy is it wet....
So what's the down side of spinning some of the moisture out of wood?
Thanks

I sometimes stand logs and boards from my sawmill on end to let some of the water drain out. Besides re-tightening the chuck a time or two to make sure it's tight, staying out of the way of the wood (and the mess), and controlling the rust I can't think of a big downside. That seems like a perfect use for the safety cage if one came with your lathe. The safe speed would depend on the size of the piece (which I don't see mentioned), the balance, the integrity of the wood, and the method and integrity of the holding.

The way I understand wood the water you are throwing is "free" water, water in the pores between the cells, so immediate shrinkage should not be a problem. The "bound" water that slowly leaves the cells when drying is what causes the shrinkage, warping, and cracking. If you spun the bowl dry then wanted to turn some more on it a little later just be sure to cover it with plastic till then or spray the surface occasionally with water.

Hey, easy to do with a hollow form but would take more effort with a bowl: I watched the other John Jordan (the famous one) connect an air hose to the opening in a hollow form and much of the free water came bubbling out through the sides! He said it did accelerate the drying process but I think he meant over the next few weeks. You could contact him and ask.

I do like turning sycamore but I've only turned dry.

JKJ

[Tim Hoyt]

Hey, Thanks for the well thought out responses.

Roger, I usually rough turn my bowls with a mortise, so I guess things could shrink up to the point that a crack could occur near the chuck. I'll keep an eye on this. The sycamore/windshake warning is VERY appreciated. Just another reason to stay out of the line of fire.

John, These bowls were mostly in the 8 to 14 inch range. I do have a safety cage, of course I didn't think of using it. I guess I'm like a lot of turners and let the cage gather dust in the corner, although I do pull it out every few months for something I'm not comfortable with.

Funny story: After a week of turning this very wet sycamore, I put a piece of cherry on the lathe last night. It was an offcut from a sawmill. I actually saw it cut 2 weeks ago, so I knew/assumed it was green. It wasn't spitting water. Made me wonder if it was dry for some reason. I actually put the moisture meter on it, 25% moisture. Back to normal reality.

[Perry Hilbert Jr]

I cut a black walnut tree about nine inches n diameter (because it was in the way) in late February a few years ago. It landed on the up hill side of the stump and sap poured slowly out of the cut end of the log for over an hour. So I tapped a few black walnut trees standing in the same area and boiled down some syrup. Every bit as good as maple. Read somewhere that sycamore could be used for syrup too. If the sap flows that well, there must be a huge amount of water in it. Seems like turning it would be like a wet sponge suddenly on a centrifuge.

[Hal Taylor]

Tried that one time - won’t do it again. As others have said the piece may come loose - mine did, and in the process destroyed lights shower/dust curtains, etc. Luckily, I was not in the line of Fire - it would have destroyed my face shield too.

[Reed Gray]

Sycamore is about the only wood I have seen that will warp as much as madrone. Main difference is sycamore warping is pretty predictable where madrone is not. If I am spending a lot of time on a wet piece, I will make sure to tighten it up a time or two as I turn, but generally in that short amount of time, it will not warp enough to make any difference. It can compress more than dry wood because it is more spongy. Black metal stains from the chuck can be removed almost instantly with concentrated lemon juice. You can spin out a lot of the free water if you leave the bowl on for a long time, but not the bound water. I learned to stand out of the line of fire by turning sloppy wet wood. There is a 2 foot wide racing stripe on the wall and ceiling in my turning room, and my left shoulder on my turning smocks are pretty discolored...

robo hippy

[Bill Splaine]

What is "wind shake" ??

[Roger Chandler]

What is "wind shake" ??

Wind shake is when due to the wind blowing/twisting the tree, the layers/growth rings separate. Sometimes you can see it, sometimes you can’t, especially on green wood. When separation occurs with the lathe spinning, it can launch and severly injure/kill a turner. Sometimes a tree out in an open field can be exposed to greater forces from the wind than a tree surrounded by lots of other trees.

[Reed Gray]

I have never been sure if ring shake/check and wind shake are the same or not. There are almost always checks coming off of the pith in any log you get. Most of the time they radiate straight out. Ring checking is cracking along the growth rings, so going around the tree rather than out from the center. Most of the time you can see it as a darkened growth ring. Some times not. The sycamore out here (London Plane most of the time rather than American Sycamore, but you have to be an arborist to tell them apart...) can get huge as in 4 foot diameter trunks. I haven't had any with ring shake. Pacific Yew has it fairly often. I had a sugar maple that had some rather clearly marked ring shake, and some koa where it was not so obvious because the wood is dark colored as well. Some times the piece that has the shake will fall out, some times it will hold on long enough to get the piece turned. If I know it is there, I use extreme caution.... As always, stand out of the line of fire...

robo hippy

[John K Jordan]

In the literature shake is called both ring shake and wind shake. The jury is apparently still out on what causes shake. Some researchers say it is some kind of bacteria. Some say from stress. Who knows. It has nothing to do with the amount of water in the wood.

Regardless, it's horrible when sawing or turning. I've had boards fall apart off the sawmill. Shake and checks are why I like to cut a thin slice off end of turning blanks grain and bend it to see if it breaks easily. If so, I'll cut more slices until the wood is solid or it goes in the burn pile. In my experience most of the ring shake when present is extensive, ruining much or most of the log. I have found ring shake on black walnut, chinese chestnut, and maple.

JKJ