I was recently turning an elm burl, and that had grain running in every direction conceivable. I wouldn't have fancied planing it, but it turned like butter fortunately! It was only part seasoned when I turned it, and now it has been inside for a couple of months, and has dried out, the top has distorted around the "pips" so much that it looks like leather! :shock:
A. The theoretical board with the grain running absolutely parallel to the face of the board - which doesn't exist.
B. The grain is more like real life with the grain running "up hill". Plane in the direction of the arrow and all will be well.
C. But try to plane "downhill" and all will be misery. Don't do it, unless...
D. You find a board like this, which you will, when you have to plane "the wrong way" for part of its length. This is when you need your plane well tuned, and expect to have to plane is all directions when you reach the smoothing stage.
Don't laugh, but it also often helps to stroke the board; it'll feel smoother in one direction, and that's the way to plane.
It can sometimes be hard to see this on the side of a board. In such cases, look at the end grain on a clean sawn surface.
If the rings dip towards the floor (think "syncline" - a geologist's term) where "syn" approximately means "with" - then plane in the direction of the cathedral arches on the face. If the rings arch towards the ceiling (think "anticline" - another geologist's term) where anti approximately means "against" - then plane in the direction opposing the cathedral arches on the face.
Syncline = plane with the arches: Anticline = plane against the arches.
If this is as clear as mud, I shall try to find a picture.
Go on then Chris - give us a picture... I satisfy myself with respect to grain direction by looking at the alternating bands and 'feel', which works for me.
That said, I have read the 'cathedral arches' line many times - but I've never been able to visualise what the hell this actually means... Pure intellectual laziness on my part, but a simple explanation would be much appreciated...
(edit - and yes, synclines and anticlines are clear as mud to this simple ex-soldier... I like 'up' and 'down', meself...)