Bowl out of round after taking off lathe.

[pete00]

Howdy

Odd thing happened a little while ago. Been working on this bowl 10â€x 6 “ had it just about ¾ way done. Took it off lathe to get a better look, kept face plate on. I played around for about 10 min. then put it back on lathe. Turned machine on and it was out of round. Got the wap..wap..wap when I put the gouge to it..

I used a face plate with four screws. Check the screws all were tight except one. Running the face plate didn’t seem to be out of wack when I put my finger on it, seemed pretty smotth. Took bowl off again and on again a few times, trying to screw it in on differently. But no difference wood still seemed to be off balance. Never removed the screws.

The bowl blank is made up of 2 pieces of cherry (3x5) glued together klin dried.
Been sitting in house for a few days. Temp when I started was around 25 it was 45 when I stopped. heat wave !!!!

Is it possible to pick up that much moisture in 10 â€" 15 min to make it change shape ?

Or is there something else sinister going on with my lathe… or ?

thanks pete

 

[Old Griz]

Yes it is....

 

[woodwish]

I've had some green wood bowls warp from one day to the next but not that fast. I have seen them warp fast if they got hot from sanding too hard, but not while still using cutting tools. My GUESS is that it was not really on straight to begin with, had a wood chip in the threads or something, but when you remounted it was clean and straight. Unless it's really bad you should be able to true up but do not remove again if possible.

I think the more serious concern here is that you are turning in a shop below freezing! Dang, I ain't that tough! [:0]

 

[dubdrvrkev]

Not only will it gain enough moisture but it will also relieve enough stress to warp in just a few minutes. I was turning one yesterday that I believed to be dry and started seeing cracks as I was turning. So I waxed it up and bach in the bag it goes. It was warping the whole time too.

 

[pete00]

thanks all
guess ill have to turn faster.....[]

 

[alamocdc]

Pete, it sounds like stress in the wood. I've seen kiln dried wood warp as it was coming off my tablesaw.

 

[woodman928]

Originally posted by alamocdc
<br />Pete, it sounds like stress in the wood. I've seen kiln dried wood warp as it was coming off my tablesaw.

Bill
That's what they call casehardened and that is caused by poor kiln drying practices. The outside dried faster than the inside and it leaves the wood under stress. I have had boards stop a 7.5 hp 16" table saw because of it pinching the blade and then I have had boards that blew apart half way through the saw. Its a wild ride when it happens.
Jay

 

[Doghouse]

It depends on the wood and the moisture. But Yes you can have warps occur while turning. You are releiving a lot of stress from dry wood when you remove the inside. Which is why you should never go back and "touch up" the lip once you have the inside removed. It will no longer be in the exact same location when you cut it. The degree of movement depends on the type of wood and how much moisture is available for gain or loss.

 

[penhead]

Speaking of moisture content, since I am thinking all pretty much agree just how amazingly wood can move, could anyone recommend a 'good' moisture meter.

I know the ones at HarborFreight have been talked about - checked those out - and also the ones that Woodcraft sells - bought my little inexpensive pin type meter there. Sometimes though, having little pin holes in a little piece of wood is an annoying thing.

But I also know there are some meters that weigh in around the $300+ mark. These are usually the ones that do not use pins, but work on frequency (i think but could be totally wrong in that). Do these work as well, actually better I would hope for the price difference? This type, I believe, also have different settings for different types of wood. Is this required only for this pinless type meter?

Anyone recommend a fairly inexpensive, pinless brand/model that works well..?

 

[Rifleman1776]

The replies are right on the money with regard to losing moisture. My thought too, was the wood was not properly dried. A master bowl turner in my club turns part way, wraps the work in a dampened towel, then puts that in a plastic bag if he leaves the lathe for even a few minutes. When the turning is almost complete, he will put the work aside for a period of time (days or weeks), then remount and turn to round. For really artistic work he leaves it warped and sells for twice the money. True.

 

[pete00]

thanks all

I guess i should rough turn piece (wet or dry), then let it sit a day or so, then finish. Now i have to worry about wood stressing out as well as me.

John HF has there meter on sale for 19.99, i got one on the way, dont know how good but its comming anyway.

thanks...pete

 

[alamocdc]

John, one of IAP's members has an expensive moisture meter and one from HF and told me that there didn't seem to be any significant difference in the result. That being said, I'd get the HF model.