Replies

1. 
   wop | Nov 10, 2005 12:48am | #1

       Be carefull with branches . They are usually used as fire wood because they are usually reaction wood.  Because of this if you use them for turning, even after drying ,the finished turning will have a tendancy to bow beacuse of the internal stress difference in the wood from one side to the other of the branch.

                                                                                    Philip

2. 
   PlaneWood | Nov 10, 2005 08:06am | #2

   There are 3 directions that wood shrinks.  Tangential, the largest amount, is along the growth rings.  Radial, about half as much as Tangential, is shrinkage perdendicular to the growth rings.  Linear (I think that's what it's called), is shrinkage up and down the tree (almost negligible).

   So, try this,  Cut a piece of limb about 4" long, clean off the bark, then set it aside to dry.  After a few days you should see a crack starting to form along the axis of the limb.  Pretty soon, that crack will probably be 1/2" wide or wider and it will extend clear into the center of the limb.

   If you cut a bowl quickly from a section of green limb and make the bottom thin enough, you might defeat this natural tendency to crack as it dries.  Soaking it in PEG right after turning would definitely help.

   But, if the first few growth rings aren't in the center of the limb, it is 'reaction' wood.  Don't mess with it other than for firewood (IMHO).

   Maybe some turners with lots of green wood turning experience will jump in here and clean up what I'm saying.  (or nullify what I'm saying!)

   Oh yeah, Vermont aught to have lots of saw mills out in the woods.  Go direct to them and get them to provide you with green lumber about 5" square.  Then build a kiln and wait 4 years for the lumber to dry.  After it is dried you will need a jointer to get the first good straight edge.  Or, you might get lucky and find some already kiln dried.

   PlaneWood by Mike_in_Katy (maker of fine sawdust!)
   PlaneWood

   
   

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   Edited 11/10/2005 12:16 am by PlaneWood

3. 
   DennisS | Nov 10, 2005 08:35am | #3

   How long are the spindle pieces you're turning? Perhaps you could riv some logs into sizeable enough pieces. If you start with a log that's say 12" across, split the log in half, then in quarters working to split it such that the pith, or the center 1" or so diamter of the log is not included in any of the quarter pieces of the log. One side benefit of this is you get much straighter grain for the spindle work by riving the blanks as opposed to sawing them.

   As green wood you will, or probably should allow it to season before turning. Coat the ends with a good green wood endgrain sealer of your choice then forget about the pieces for a few months.

   Like Mike said, branches are subject to a lot of bending stress thus there's probably a log of reaction wood especially close to the main trunk. I'd look at the option of splitting out logs, assuming you don't have suitable re-sawing facilities. You can get a ripping chain for a chain saw to rough out the log as well.

   In addition I think a branch 4+" in diameter will be difficult to season without having it split on you.

   What species of wood are you thinking of working with as branchwood?

1. 
   ianburgin | Nov 10, 2005 05:16pm | #5

   I was thinking of turning walnut, sugar maple, and cherry.  Perhaps my best bet is to split the logs like you described and just laminate in the meantime.  I appreciate all the responses, guys.  This is my first time using the discussion and I've already learned a lot.

4. 
   Telemike | Nov 10, 2005 08:53am | #4

   Like the other posters said, the rounds will shrink too much to be usable because they'll crack radially. I've turned some branches without cracking, but they came from extremely slow growing woods that don't shrink much at all because they're mostly dry to begin with. These are semi-desert chaparral brush like manzanita, chemise, and buck brush and some yew from landscape in San Francisco. The common characteristic of these woods is that they grow really slowly and you need a magnifier to see the growth rings. Even then they don't always dry without cracking.

   I'd agree that split quartered logs may dry OK if you can wait. There's a reason why thick hardwood is so expensive.