end grain -- alternate or not for table top?

[Gil Liu]

Have read several differing opinions on assembling a table top and thought I'd ask this forum. Some say to alternate the end grain, while others say to keep end grain in the same direction. I'm planning to try making a mission style table out of quarter-sawn oak. The planks have been sitting for 6 weeks in my shop. My jointer is 6".

Thanks,
Gil

[Gary Keedwell]

Gil
No need to alternate with QSWO. Some people like to alternate Plain-Sawn because of the rings, they will cup. I work with alot of QSWO and I just pick my boards to moke the most pleasing top.
If you look at the ends of the boards, you would be hard-pressed to figure which way to alterante them, anyways.:)
Gary K.

[Cody Colston]

I say don't worry about alternating the end grain. Just arrange the board faces to give you the most attractive table top.

If the wood is going to move, it will move, regardless of orientation.

[Bob McGovern]

Hi, Gil. For flatsawn stock, there are two opposing camps: those who think alternating heart/sap wood cancels out seasonal cupping; and those who think uniform cupping is easier to control & preferential to 'waviness.' The latter advocate all boards oriented the same. Myself, I just glue up according to best grain match, color, and figure & ignore the whole debate. It works just fine.

HOWEVER! You say your wood is quartersawn. That's an entirely different matter. There's a solid consensus on quartersawn edge gluing: match sap to sap, and pith to pith. Otherwise, you can get sharply defined ridges at the glue lines as the adjoining boards swell & shrink at differing rates.

[Jim Becker]

When I glue up boards for a large surface, such as for a table top...the grain match and color takes precedence over which side is the inside or outside of the log. It really will not matter if the piece is constructed to properly support the top and also accommodate wood movement. The look of the top is primary.

[Rob Will]

HOWEVER! You say your wood is quartersawn. That's an entirely different matter. There's a solid consensus on quartersawn edge gluing: match sap to sap, and pith to pith. Otherwise, you can get sharply defined ridges at the glue lines as the adjoining boards swell & shrink at differing rates.

Bob,
What happens if all of the sapwood is trimmed off of the QS oak? Do we still need to orient the boards with pith to pith and outside to outside?

Once the pith and sapwood is removed, does the remainder shrink / swell at a uniform rate?

Also, if I have wider (12"+) QS oak, can it safely be used in a table top? Anybody have an opinion on the practical limit for board width when using QS oak?

Thanks,
Rob

[Joe Jensen]

I say don't worry about alternating the end grain. Just arrange the board faces to give you the most attractive table top.

If the wood is going to move, it will move, regardless of orientation.

I respectfully disagree. Wood movement is actually quite predictable. There is a great book, "Understanding Wood" by Hoadley. If the end grain is perpendicular to the face, (true quartersawn), it won't cup. The less perpendicular to the face, the more the board will cup. There are tables in the book for every species. You can calculate how much a board, (or top) will move during the year with humitity changes. For example, I live in AZ and it's pretty dry here, and never very humid. I have a red oak kitchen table that is 37" wide 6/4 stock. Here it changes width about 1/2" from widest to narrowest during the year.

If you have quartersawn (true) stock, it doesn't matter, but if the wood is mostly flat sawn, or variable, you will have the most luck with alternating the end grain direction....joe

[Bob McGovern]

Rob: The wider the quartersawn board, the more pronounced the wood movement differential from one edge to the other. A 12" wide Q-sawn board (Wow! I'd love to find that) means one edge is very dense heartwood, and the other is quite young growth -- may even have sapwood attached. (Unless you have a board that spans an entire log, sawn thru-and-thru.)

We all know wood moves about twice as much in its tangential plane as in its radial plane; that's why quartersawn wood will move half as much laterally, great for wide items like tabletops. But we forget the corollary: that quartersawn wood is less stable in thickness than flatsawn wood. And butting together new growth and old is asking for visible glue lines, even cracked finish.

I'm not one for spewing back by rote the wisdom of the old masters. I generally observe this rule, because it matches what we know about wood movement. Enh ... but maybe you can ignore it without consequence. I can think of four situations when it doesn't matter:

1) the plank is sawn thru-and-thru; both edges of the board are sap, and the center is pith.
2) you are using a stable wood with low tangential movement. Like mahogany, or yellow poplar.
3) you are using fairly narrow boards (six inches or less?), or wood from warm climates: not so much density difference between one edge and the other.
4) you live in a place/house where seasonal moisture content doesn't change much. Here in Wyoming, we are 7% year round. In Michigan or West Texas, look out!

[Bob McGovern]

Hi, Joe. See Hoadley, page 81 for a graphical view of why gluing bark (sap)- to - pith is a bad idea in quartersawn lumber.

[Cody Colston]

I respectfully disagree. Wood movement is actually quite predictable. There is a great book, "Understanding Wood" by Hoadley. If the end grain is perpendicular to the face, (true quartersawn), it won't cup. The less perpendicular to the face, the more the board will cup. There are tables in the book for every species. You can calculate how much a board, (or top) will move during the year with humitity changes. For example, I live in AZ and it's pretty dry here, and never very humid. I have a red oak kitchen table that is 37" wide 6/4 stock. Here it changes width about 1/2" from widest to narrowest during the year.

If you have quartersawn (true) stock, it doesn't matter, but if the wood is mostly flat sawn, or variable, you will have the most luck with alternating the end grain direction....joe

With what part of my statment do you disagree...The fact that wood will move or the advice to arrange the boards for the most attractive appearance and ignore the grain orientation?

I don't have to read Hoadly to learn that wood will move tangentially...I believe even Noah knew that. And if it cups, I'd personally rather deal with a bowed top than one with a washboard surface.

Respectfully,

[Joe Jensen]

Hi, Joe. See Hoadley, page 81 for a graphical view of why gluing bark (sap)- to - pith is a bad idea in quartersawn lumber.

Great one, thanks.

joe

[Jesse Thornton]

For what it's worth, here's what Andy Rae has to say on the topic in 'The Complete Illustrated Guide to Furniture and Cabinet Construction':

"How should you orient the annular rings when you edge glue planks to form a top? The correct approach is to arrange your boards so the growth rings all face in the same direction - an easy task by looking at the end-grain pattern on the end of each board. There are two reasons to avoid alternating the grain: The first is that, as individual boards move and cup, the top takes on a washboard-type surface. Second, alternating boards results in a visual light and dark contrast between different boards, most noticeable when strong light rakes across the top. With matched boards, you'll get an overall curve, which will be held flat by the frame or case that supports it. Plus you'll achieve an even reflection or contrast as the light plays over the surface.
Once you've arranged the boards facing the same direction, you need to decide which face to show. Whenever possible, avoid the "outside" of the tree. You'll find it best to display the inside of the tree on all the show faces. This surface has a richer grain pattern and a deeper reflection."

I though that last part was particularly interesting. It wasn't something I was aware of until I'd read that, even though I'd heard several variations of the alternate-or-not debate. Of course, if the 'outside' of the board just plain looks better, it's a no-brainer, but if they both look fine I take Andy's advice and opt for the inside face.
An easy way to remember which side goes up: The end grain should 'smile'. ;)

[Joe Jensen]

With what part of my statment do you disagree...The fact that wood will move or the advice to arrange the boards for the most attractive appearance and ignore the grain orientation?

I don't have to read Hoadly to learn that wood will move tangentially...I believe even Noah knew that. And if it cups, I'd personally rather deal with a bowed top than one with a washboard surface.

Respectfully,

The part I pasted in bold.
I say don't worry about alternating the end grain. Just arrange the board faces to give you the most attractive table top.
If the wood is going to move, it will move, regardless of orientation.

It's true wood moves, no arguement there, but it moves differently depending on grain orientation. I interpretted that post to mean that wood moves willy nilly.

Also, you said in your first post
Just arrange the board faces to give you the most attractive table top. Now you are saying to arrange will all the same direction.

It's ok for us to disagree, and debate is fun as long as it stays civil. Cheers...joe

[Russ Filtz]

I had a relatively narrow, but long, bar top out of maple cup upwards quite a bit (a lengthwise cup, transverse). I had alternated most of the boards, but happened to forget a couple in the middle due to matching wood grain concerns. I cranked it down with a caul to flatten and sure enough, got a nice crack right in the top surface. Wasn't too bad so I jury rigged it with epoxy to fill the gap. Hard to even tell now. Should have re-ripped the whole top and re-glued, but too lazy!