Sunday afternoon with problems

[Mark Stewart]

This is a small green bowl I turned this afternoon. As I am still kindof new to "Bowl Turning" let me tell you what happened to the last two attempts. I mounted this one on the face plate, did a good job of centering. Took extra time to line it up.I started to rough out to OD of the bowl an got a vibraton. it continued all the way through the turning. As you see from pics I ended up with lines on the inside and the out side two small places that wont clean up. My other question is what do you put on a gerrn turning? I have bees wax on this one. wasnt sure whatelse to use.

sorry these are a bit blurry sut its a cheep camera. Thanks For looking ans a s allways thanks for all the advise I get from all of you.

Thanks Mark

 

[DaveO]

Mark, one of the issues you might have with green bowl turning is movement while you are turning it. If you ride the bevel a lot it can create heat by friction and start the wood warping. I had that problem with my last green turning, but it had a bit more to do with the time it took to turn it. Most green wood turners quickly rough out a bowl and set it aside to finish drying and then turn it again to take out the warp. A good rule of thumb is to turn it down to about 1" thickness and then employ one of many method to allow it to slowly dry until it's stable and can be re-turned.
I don't have the patience for that, nor the space to store turning while they dry. So I often turn green to finished and let the bowl do what it wants. Then I call it ART. If you turn to a consistently thin wall and watch the heat generated by ridding the bevel and sanding, the final product shouldn't crack, but might warp to a more pleasing form that is not possible off the lathe (think oval or Pringle Chip shaped). My green to finished bowls usually get some BLO and then paste wax. You wouldn't want to use a film finish on them as it might crack as the piece moves. But after a few weeks in the house, and all the movement occurring you can go back and Lacquer, Shellac or Poly the piece, providing you clean the wax off first.

Dave

 

[FredP]

dave gave good advice as usual.:icon_thum when I turn to finish green wood I dont finish the bottom. this allows the moisture a place to go as it dries.

 

[Trent Mason]

Mark,

I think it turned out very well. As far as the vibration goes, the only thing I can think of is that it became off center. The wood was green, so it might be more prone to "movement", "shifting", etc while you were turning it. I know I had problems with that on a big bowl of Claro Walnut that I turned. I think that one side of it was more dense than the other, so when it was turning on the lathe, the unequal weight distribution made it wobble quite a bit.

As far as finish goes, if you want it to dry as easily as possible, over time, I think you need to use a sealer and put it away in a paper bag for 6 months. Then take it out and touch it up on the lathe, as it will probably not be round. I believe the sealer does a good job of keeping it from cracking as it dries. I haven't actually done this, but I saw it on a dvd one time. I would definitely check that out. It helped me out quite a bit. DaveO taught me everything I know about finishing bowls and I use BLO and paste wax. I'm sure some folks will give you more/better advice than this, but HTH. :icon_thum

 

[Mark Stewart]

So if I have a green blank that has been was sealed how long do you let it dry befor turning?

 

[DaveO]

If it's a hunk of green wood that has been sealed with a wax emulsion (like you often buy from a turning blank supplier) it won't dry in your life time. If you have green wood blanks sealed or un-sealed you need to rough turn them to a larger than finished diameter then allow them to dry. Removing a large majority of the wood will allow them to dry much faster. How you let them dry, or enhance the process is a matter of choosing your methods.
Many folks pack their rough-turned bowls in shavings and then place them in a paper bag. That slows down the rate of moisture loss.
Other enhance it by soaking the rough-turned bowl in Alcohol, dish-washing soap or something else that will drive the moisture out of the wood.
Here's a little info on Alcohol Soaking
Green wood turning
More drying methods
Still more info
Green to finished fun
Pentacryl


Dave

 

[DaveO]

So if I have a green blank that has been was sealed how long do you let it dry befor turning?

I guess the most definitive method is to weight the blank when you get it and keep checking the weight until it stops losing weight. Once that has happen it's lost all the moisture it can and reached Equilibrium Moisture Content (EMC) with its environment.

Dave

 

[Mark Stewart]

Daveo, you r da man. I thank you for all your knoledge sharing and I enoyed meeting you and the others at the picnic. Thanks again

Mark

 

[BobcatBob]

I don't think Dave O missed a thing. :icon_cheers.

 

[Mike Davis]

Were you gripping that bowl by the small protrusion on the back?

That may be your problem, the size looks a bit small for the bowl. What kind of chuck and jaws did you use?

Can you show a picture of it mounted?

Green wood is very flexible so you need a good strong surface to grip. It can bend and twist while you are turning and you may not notice, but wonder why it seems wobbly.

Next time try a bigger stub or make an inset so you can grip it with the outside jaws of the chuck. Of course then you have to leave enough wood so it doesn't split.

Or just tell me I'm full of it, I get that a lot. :rotflm:

 

[Mark Stewart]

No Mike iI dont think you are full of it I appreicaite all this (what I think of as)good input. I have a small new river chuhk on a mini lathe. I think next time I might try gripping from the inside. These are some small blanks I got off oe ebay a while back. I think part of the problem may have been dull tools:embarrassed: I stilll need to work on my sharpening skills. But yester day I got my self a wolvereen system. Might just get a bit better today.

Thanks for sharing what you know. Thnaks for the help.

Mark