How far to go

[woodfarmer]

Today I had a bit of respite from trying to turn some rather hard oak I have and started to make up my first bowl blank out of some lovely green pear wood I was given. I have never used green wood before. So some questions.
When I rough turn the blank, how thick should I leave it to dry before finish turning it?
This blank illustrated led me to the shape and form it is, but there are still bits of bark etc. Should I turn all of that away?
Is it possible (and advisable) to finish turning green wood?

 

[Bodrighy]

In my experience green fruit wood in general will split unless you turn it really thin and let it warp and twist. You can of course turn ity to about twice the thickness you want it eventually, wrap in newspaper and put on one side wit fingers crossed but unless you are luckier than I have been it will still split. Other may have some way of preventing it using plastic bags that you invert every few days but apart from that I await others experience.

Pete

 

[Woodmonkey]

Agreed, fruit wood is a bugger for splitting as it drys out. As pete says, you can turn it thin so it dries quick, you'll need to sand it with some wet & dry while its still wet as it will be difficult or impossible to put it back on the lathe once it has warped. I have had some success using a microwave to speed up the drying process.

Rich

 

[bellringer]

pear is the worst wood to turn green

 

[renderer01]

WF, mate
There is a bucket of good advice here and I agree with all of it to some extent. The fruit woods are really twitchy, The only thing I feel I should add is that all pear isnt the same, same for apple / cherry whatever they have a greater tendency to go pearshaped! :roll: but just because one tree cracks to firewood doesnt mean another grown elswhere will do the same. If its cut in the winter after tree has shut down you have a better chance maybe.
I think you have a lot of reading to do but maybe even more experimenting.
Trying to help matey, hope this has.
Just a thought wet wood I like is birch/ elm/ ash/ maple, but all require care, if you need ask and will send you some links.

All best
Rend.

 

[chipmunk]

Just a couple of thoughts.

PVA as a sealer slathered all over the outside (not the inside of the bowl) of your rough turned bowl will help slow down the drying. I'd also try to take some weight out of the foot area as this is where rough turned bowls often spit and I'd take off all of the bark.

If you decode to turn it thin from green then when you get to hollowing take the bowl down to final thickness in steps beginning at the rim. Don't try to gradually reduce the overall thickness a bit at a time.
Turn, sand and finish only about 1/2 - 1" at a time and work your way down from teh rim to the bottom and don't expect to be able to go back to the rim when you get into the base.

HTH
Jon

 

[Paul.J]

Isn't the rule of thumb to turn down to a third of the dia.So if a piece is 300mm wide you leave 100mm for drying??
The wall thickness has gotta be even all the way down but as Chipmunk says its usually the tenon that splits.
Make sure the pith is well out and anywhere there were small branches seal those well.
On saying that i had some pear and it turned lovely,a really nice wood to turn and in fact it was a piece of wet pear that was my deepest/biggest hollow form nearly 14" deep if i remember right and it didn't move at all.

 

[woodfarmer]

Thanks for all your help, this one I started to turn to clean it up, so have gathered if I just make clean blanks and dry them slowly I might get some good bowls...

 

[chipmunk]

Isn't the rule of thumb to turn down to a third of the dia.So if a piece is 300mm wide you leave 100mm for drying??
The wall thickness has gotta be even all the way down but as Chipmunk says its usually the tenon that splits.
Make sure the pith is well out and anywhere there were small branches seal those well.
On saying that i had some pear and it turned lovely,a really nice wood to turn and in fact it was a piece of wet pear that was my deepest/biggest hollow form nearly 14" deep if i remember right and it didn't move at all.

Hi Paul, I reckon on closer to 10% than 33%.

So for your 300mm bowl I'd leave the sides about 30mm thick but the base would also be about 30mm thick too.

HTH
Jon

 

[Paul.J]

Isn't the rule of thumb to turn down to a third of the dia.So if a piece is 300mm wide you leave 100mm for drying??
The wall thickness has gotta be even all the way down but as Chipmunk says its usually the tenon that splits.
Make sure the pith is well out and anywhere there were small branches seal those well.
On saying that i had some pear and it turned lovely,a really nice wood to turn and in fact it was a piece of wet pear that was my deepest/biggest hollow form nearly 14" deep if i remember right and it didn't move at all.

Hi Paul, I reckon on closer to 10% than 33%.

So for your 300mm bowl I'd leave the sides about 30mm thick but the base would also be about 30mm thick too.

HTH
Jon

Is that what it is Jon,I knew i was going wrong somewhere :lol:
Its been that long since i done any wet turning.
Thanks for correcting :wink:

 

[tekno.mage]

I sometimes rough turn bowls from green wood and leave them to dry before finishing them. More don't split than do split, most go very oval! I've even managed to do this with freshly felled holly (a notriously difficult wood to dry). The key things that I've found are important are:

1. Make sure the wall and base thicknesses are roughly even - they can be quite thick (25mm - 35mm)

2. Notice where every potential defect is in the wood - every pippy bit, every knot, every bit of pith where a twig joined on - and paint both sides (inside & out) of every potential defect with PVA

4. Paint the end grain on the bowl with PVA.

5. Allow the PVA (which should be a relatively generous coat) to dry, then store the roughed bowl in a cool, dry place out of direct sunlight for around a year before returning to to finish.