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Apple logs

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Mark Sanger:
Hi Malcy

I hope you don't mind I have taken the picture of your log and added some graphics to help me explain.

Great advice, I just want to add a few bits. ( If I am teaching you to suck eggs I apologise).

The log you have here is 'Reaction wood', this is wood that has grown under stress and results in the pith being off centre and the growth rings condensed to one side.

Reaction wood is of little use for the turning of end grain hollow forms or vases, yes you can rough it out but the resulting uneven shrinkage during seasoning means that a form has to be roughed much thicker and seasoned much slower than 'Normal' wood where the pith is central and the growth rings concentric. Often such a processed form will crack unless turned to a thin wall and allowed to move as a result I generally only use it for bowls as shown. And you will find that it is not worth the bother.

So the best option is if any to cut through the pith aligning the growth rings to be balanced out across the bowl either side of the pith.

'Reaction wood' means that its shrinkage rate is greater with it being far more prone to failure than normal wood due to the stresses under which it has grown. People often think that by balancing up the symmetry of growth rings that it will act like 'normal' wood, this is not the case.

This is not a major issue you just have to take a few things into account.

1/ Reaction wood will shrink and move more than the same species when processed from 'Normal wood' , so it has to be roughed out to be thicker in cross section, as indicated on the picture, 20% of dia for 'reaction wood', and 10%- 15% of dia for 'normal' wood ( depending upon the species). Fibres that have grown under a higher level of stress than normal require sympathetic seasoning, with it being slowed down to to a minimum, around twice as slow as normal. This allows for the fibres to shrink and relax slowly without failure.

Fruit wood by its nature is slow growing and therefore dense, with fibres that are less flexible than with a faster growing woods, such as sycamore and Maple. So fruit woods of all kinds have to be seasoned much slower or the fibres will fail quickly with the wood cracking.

I leave my fruit woods in plastic bags, reversing the bags every 3-4 days, whereas Sycamore I will do it every 1-2 days. I then keep it in a open bag again for twice as long as for sycamore, around 2 months.

Hope this helps.

TWiG:
Further to Marks very good explanation of reaction wood .....  Reaction wood is the trees response to stress in the wood  eg from the tension and compression that occurs on lateral branches or on leaning trees or trees regularly exposed to prevailing winds , the tree responds to this stress by increasing growth where extra strength is required , interestingly this is on TENSION wood in Hardwood species , and COMPRESSION wood on conifers !   an old timber merchant I often used to work with used to just look at the trunk ( when felled ) and say ?!"%*ing useless the middle is not in the middle !! so it is no good for planking .   Terry...

ravenge:
Great explanation by Mr Sanger!!!
Don't know how long you have been turning, but sometimes when I was starting to learn I would mount the most nasty pieces of wood that people had given me (friends and family and such) and turn them knowing they would split/crack just for the practice (try different cuts and such) and just whittle the wood away, I'am a real cheap-skate and hate throwing it away without getting some use from it (the wood that is)
If you are not new to woodturning and are a competent turner then please accept my apologise (I'am new to this forum sorry!!!)

woodndesign:

--- Quote from: ravenge on April 04, 2013, 12:39:02 AM ---Great explanation by Mr Sanger!!!
Don't know how long you have been turning, but sometimes when I was starting to learn I would mount the most nasty pieces of wood that people had given me (friends and family and such) and turn them knowing they would split/crack just for the practice (try different cuts and such) and just whittle the wood away, I'am a real cheap-skate and hate throwing it away without getting some use from it (the wood that is)
If you are not new to woodturning and are a competent turner then please accept my apologise (I'am new to this forum sorry!!!)

--- End quote ---

Ravenge, Welcome to the forum and all comments are welcome, keeps things active ..  ;) ... so don't be sorry, look forward to reading more from you and seeing the results of you're whittling, that's a first in turning terms.

Mark & TWiG thank you for your enlightening explanations.

Cheers  David

Mark Sanger:

--- Quote from: ravenge on April 04, 2013, 12:39:02 AM ---Great explanation by Mr Sanger!!!
Don't know how long you have been turning, but sometimes when I was starting to learn I would mount the most nasty pieces of wood that people had given me (friends and family and such) and turn them knowing they would split/crack just for the practice (try different cuts and such) and just whittle the wood away, I'am a real cheap-skate and hate throwing it away without getting some use from it (the wood that is)
If you are not new to woodturning and are a competent turner then please accept my apologise (I'am new to this forum sorry!!!)

--- End quote ---

Welcome to the forum

The more the merrier, don't be shy and I am looking forward to seeing your work.

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