Radially spit, tangentially split? Orientation? It all matters.....
Right then. If you've read the previous two posts you should have a pretty good understanding of the principles behind spoon carving, if you haven't, and you're wondering what the hell a "billet" is, go and read 'Splitting Logs for Spoon Carving' .
There is one more important step in sorting out your log before you start swinging that axe and getting into the fun stuff. Where is the spoon inside the log? Or more to the point, where will you put the spoon in the log?
Where you orientate the spoon in the billet is very important. Aside from aesthetics (more of that later) it is essential to ensuring the spoon doesn't crack, and also to minimise 'movement' in the wood as it dries. As mentioned previously, the centre 'pith' must always be removed, as should the surrounding first few growth rings as these are inherently unstable.
Expanding on the previous post, we are going to learn about two new terms to help understand how splitting logs affects the finished spoon.
Radial & tangential splitting....
The angle at which the growth rings of a piece of wood meet the finished surface will change depending on how the billet was split. This will effect how the wood dries and also how the finished spoon looks. There are two new terms we need to understand to continue.
Radially split & Tangentially split.
or, split on the Radius or Tangent.
The image below explains the difference.
The green marks indicate radially split wood. The blue tangentially split.
Note that on both billets, the wood near the centre of the log has been avoided
Radially split wood, if done correctly, is inherently very stable. The three rectangular billets I split out in the previous post are split this way. You can see when looking at the end grain that the growth rings all run nice and parallel across the billet. This means aside from minimal shrinkage between those rings, across the width of the billet, there should be very little other movement as it dries.
For tangentially split wood the opposite is true. The growth rings run perpendicular to the edges of the billet. As the wood dries, these rings will want to flatten out, creating some movement in the final spoon. This is the reason we orientate our spoon near the outside (bark) edge of the wood in this instance, because here the growth rings are wider and thus will move less as they flatten out.
When we cut through wood to create the bowl of the spoon, we are cutting through these growth rings. In a radially split billet, looking down at the 'top' or 'face' of the spoon, the rings show as long lines of grain running along the length. On a tangentially split billet, the rings go down into the spoon (when looking at the top, or face of the spoon). As the bowl of the spoon is a concave shape, and as the growth rings become smaller the deeper we cut, the concentric circles of growth rings begins to show themselves and create a wonderful effect. With practice and care you can orientate the spoon just right so the smallest concentric circle is exactly at the lowest and most central point of the bowl, creating lovely symmetry across the whole spoon.
radially split wood
tangentially split wood
Finally, here is a little video showing me splitting off the waste wood on a round log to creat a nice, rectangular, tangentially split billet, with a nice sweep through it to boot!
So, now you know! Enjoy playing with different splitting techniques to create different effects on your spoons, safe in the knowledge they should dry nicely and not split!