Width, Length and other Ambiguities

[jbry3]

Sooooo..... being nonprofessional, I found myself doing a double-take when magazine articles use the word "width" when I would have expected "length", or vice versa.

It took a couple decades, but I finally came to the conclusion that "width" means "across the grain"...."length", along it.....irrespective of the actual dimensions of the board (a board could be much wider than its length, and up until my new understanding I would have reversed the words, to apply "length" to the longest dimension).

And then p29 in the current WOODSMITH, in discussing how to make crossgrain splines, says to "cut the splines to width (length)." aaaaack! I do see what, in their normally helpful way, they are talking about.....but got me to thinking.

Which led to my overthinking things and now I have a need to know.

Let's say you have a board that is 1" thick, 3" wide, 6" long. The "ends" are where the grain shears off. The "edges" are the thinner sides. The "faces" are the wider sides.

But if I were to rip a thin strip off ...say 1/2" wide, so that the smaller "board" is 1 x 1/2 x 6...have the "edges" and "faces" changed places? Is the "edge" still the thinner (1/2") side? If I rotate that board axially, the wider side (1") looks like a "face" to me. Or is there some subtle grain differentiation that I don't get?

Or did I overthink myself into stupidity?

john

[Chris Friesen]

Personally I'd say yes. The edge should be the thinnest side that shows long grain.

Of course it gets tricky if you have pieces with a square cross-section. :)

Incidentally, for cabinetmaking plywood the second dimension is the grain direction. So an 8x4 sheet has the grain going the short way.

Chris

[Nonny]

Thanks, I learned something today.

[-MIKE-]

Sorry, this is a tangent....

A pet piece of mine is when "woodworkers"-- especially ones on TV shows-- say the word, "heighth."

They think that somehow, because length, width, and depth, have a "th" sound at the end, then so does height. Sometimes, I'll jokingly say, "Hey, height only has two H's."

[Max]

Lowe's has some 4X4 sheets. What is one to do?

Max

[SonomaProducts.com]

Ehh... you need to be careful for what purpose is the statement being made.

Face and edge mean very specific things when you are considering grain. Edge grain is very different than face grain in terms of apperance and somewhat structurally when gluing. However, even that has some ambiguity because you cut wood from round logs.

So if you cut a 4" square timber from the center of an 8" round log it has face grain on 4 faces.

However, if you slice a 1" thick board from the same round log (rather than a 4x) it has face grain on the wide "faces" and edge grain on the thin sides. The face always shows edges of rings to varying degrees while the edge shows to varying degrees the faces of rings. The piece cut from the center of the log will have an edge grain with almost completely the face of a ring. Confusing enough?

An edge to edge glue joint is super strong. A face to face glue joint is super strong. An edge to face glue less strong. This last sentence is conjecture on my part but it seems to bear out in my experience but matbe because edges are usually narrow and faces usually wide so the joint has available leverage to break it.

[Chris Friesen]

Your conjecture is false.

The fact that longer pieces confer more leverage doesn't imply anything about the strength of the joint itself.

And besides, an edge-to-edge joint with the same glue area has at least as much leverage potential--imagine holding onto the edges of a panel and bending it over your knee right along the glue join.

Generally speaking a well-constructed long-grain to long-grain glue joint is as strong as the wood itself regardless of growth ring orientation. This is a simplification, but one that works in the vast majority of cases.

Chris

[Swingman]

More importantly, most "boards" are cut from the "length" of round logs.

Tree cells are generally elongated and and that elongation is aligned to carry water and nutrients along the length of the tree trunk (log) and limbs.

"Long grain", running along the length of elongated cells structures, and "end grain" running across the elongated cell structure, are much better terminology for joinery/gluing purposes, IMO.

Not to quibble, but I would tend to disagree somewhat with that conjecture.

Long grain to long grain, whether it be on a "face" or "edge", should have the same relative glued strength characteristics for the most part and, MOST IMPORTANTLY, should also the same relative dimensional stability for joinery/gluing purposes (although the way it was cut from the log (i.e., flat, rift, QS, etc) will cause some differences in the latter)

Why? ... mainly because both have same elongated axis of cell structure exposed to the chemical reaction of gluing.

[SonomaProducts.com]

Chris and Swing,

I stand corrected. I really started out just to say that width usually means face grain and actually never said it and tangented off into other topics. I've never done that before.

Who knows, maybe I am also wrong about the health care thing being another government sink hole for my money with minimal return. I hope I'm wrong.

Caveat: Not a real woodworker, I just play one on TV.

[Swingman]

LOL ... in that regard, you're more than one up on me! :)

I really wasn't trying NOT to be a smart ass, sorry if it came across that way.

If you use your head for something besides a hat rack, you can't argue with that bottom line, and the perspective.

I'd also take exception to that ... your work speaks otherwise.

[jbry3]

You mention the different cuts, Karl. When I see them drawn in magazines, I understand the difference among rift-, quarter-, and plain-sawn...but damned if I ever could tell by looking at an actual piece of wood. Maybe it's just that I've only "played at" woodworking off and off for 30 years....

Although....thinking about it, I *do* see that the oak in front of me has those weird spots ("pickling"?) only on the "edge" and when I make banding I prefer to put the "face" out front of the plywood shelf.

john

[SonomaProducts.com]

[Chris Friesen]

Look at the end grain and you should be able to clearly see the growth rings. The angle of the growth rings relative to the surface determines whether its quarter or plainsawn. If the ring is less than 45 degrees relative to the face it's plainsawn, more than 45 is quartersawn.

Rift-sawn is sometimes also called bastard-sawn, and means that the rings are 30-60 degrees relative to the face. This can be useful for legs as it means you get similar figure on all four sides.

Chris

[Swingman]

Although....thinking about it, I *do* see that the oak in front of me has

Those weird spots are medullary rays and characteristic of quarter and rift sawn, particularly noticeable in red and white oak.

You will notice that often plain or flat sawn woods do have a very apparent quarter sawn edge. AAMOF, I often seek these pieces out when I want to show the edge in a drawer/dust divider where the rest of the wood is quarter sawn, as you can see here:

the wood is thick enough, say 3 or 4", you can actually make a wider quarter sawn board out of it by ripping it to thickness.

If you really have an eye for picking out and buying rough lumber, you can save money by buying rough stock and seeking out a real thick plain or flat sawn board (which are generally cheaper) that exhibits the typical quarter sawn medullary rays on the edge, and then rip it to the appropriate thickness in the shop for some nice quarter sawn boards.

Lots of graphic info here on all the above:

[Robert Bonomi]

Do what a purported disconnected number recording at MIT once advised:

"The number you have called is imaginary, Please rotate your phone 90 degrees, and try again."

[Max]

But of course. Why didn't I think of that.

Max (hitting himself in the forehead)

[Bill]

Cute. You mean multiply it by exp^(i \PI /2). I've never seen the word imaginary and degrees in the same sentence--no, never before. Obviously undergraduate MIT students... I guess you could use the cord for the initial side of the angle of rotation---but, what if you only have a cell phone?

Bill

[Steve Turner]

As in "That bastard sawn my wood rong!" ? :-)

[Robert Bonomi]

No, I don't 'mean' that. :)

If I'd said that, it would *not* have been acurate reportage of the story _as_I_heard_it_.

Admittedly, it is a complex subject.

But, even with 'pure' imaginaries, it's still a matter of degree.

what's sqrt(-i), for example? "imaginary in the 2nd degree"? *GRIN*

[Bill]

sqrt(-i) = exp(-PI/4) or exp(3PI/4). Not "purely imaginary" at all--the real part is +/- sqrt(2)/2. It's as plain as a point on the unit circle. You could double-check that if a = sqrt(2)/2 - sqrt(2)/2*i, or b=-a, then a^2=b^2=-i. Simple trig and De Moivre's Theorem...

Bill