Jeff explains the importance of selecting straight, long-grain material for chair-making, emphasizing the need for large logs to maximize usable heartwood. He highlights the aesthetic value of straight grain in chair design and the significance of milling parallel to the log's pith for optimal results. Jeff's methodical approach to finding and utilizing straight grain in live edge boards underscores the key role it plays in creating strong joints and beautiful chairs.
Transcript
Jeff: For the round tenon and round mortise, there are six components of making that a strong joint.
We're going to start with long grain and a straight grain. And straight grain starts with choosing a log.
00:23 Choosing A Log For Straight Grain
People look at this process of the Boggs chairs as dissimilar from the Jenny Alexander chairs. The greenwood chairs: "Make A Chair From A Tree".
Now it's more clear the process of log to chair or tree to chair in a greenwood chair. But these chairs are the same way. We go back to the log.
And so the first part of the process is log selection. I'm looking for logs that are as straight as possible, as boring as possible. No evidence of large knots, you know, a big, what they call that, a cat's face. I look at the grain in the bark. If the bark looks like it's running straight up and down, good chance the grain inside will be doing that as well. If the grain, if the bark is twisting around the log, that's probably a pretty good chance that it won't be a good chair log.
Might be good for other stuff, but not chairs.
So we're looking for really straight logs, boring as possible.
Mark: So no curly figure?
Jeff: No. No crotch wood, none of that.
01:35 Why You Need A Big Log
And also as large as possible for our purposes, I would say the very minimum diameter would be 15 inches. But that's, that I'm absolutely not going below 15 inches.
Because you have about four inches in the center that's basically unusable. All that juvenile wood you can't use. And then you often have inch or two inches on the outside.
That's sapwood. I always mill off the sapwood.
And so, if you have 15 inch log, you take out four inches in the middle, and you take out two inches on each side, you're left with seven inches split (in half by the pith). You're only left with three and a half inches of good heart wood on either side of the pith.
There's not much you can do with this. It's not useful in what we're doing.
So I would say an effective minimum would probably be 18 inches. But the bigger the better. If you get a two foot log or a 30 inch log, that's even better. You'll get lots of good usable lumber out of that.
02:50 Mill Your Boards Parallel To The Pith Of The Log
The other thing, when you're milling the log, you need to get a sawyer that's going to pay attention to the milling.
Every log, no matter how straight it looks, is always a taper. So you want to get the pith parallel to the path of the blade. And then from there, I generally just mill through and through. I don't do anything special.
03:15 Straight Grain Contributes To The Design Of The Chair
The thing I like about what this constraint of using milling for straight grain, and doing everything possible to get straight grain, because of the joinery is that to me, it ends up with a beautiful chair aesthetically.
We make this choice, a quarter song for the slats for because of the joinery. This nice subtle straight grain provides a nice... is just the right amount of emphasis on slats and not too much. The wood is beautiful in and of itself, but I'm not relying on wild grain. That's for sure.
Mark: Okay. Yeah.
Jeff: And I know people have suggested, you know, why not put something that has wild grain in the slats. And to me, it's too much for the chair.
04:05 How To Find Straight Grain Parts In A Live Edge Board
So this is a lot of live edge board. You can you can even clearly see the sapwood in this. So what I'm doing is I'm laying out the parts off of this board.
In general, with a live edge board, you can have the straightest grain parallel to the to the bark edge. So that's what that's what I'll do. This was the first line I drew. I drew a line here parallel to bark edge, milling out all of the sapwood and did another one here.
I always mill out the sapwood, mainly because I'm teaching and when students want cherry and they want that (dark) color and not that (light) color.
Essentially, you're creating a reference surface with this cut. And then I measure off three and three quarter inches for an arm blank. And you can see one arm blank here and one arm blank here. I measured off two and a quarter, two and a half here, two and a half here. That will give me two rungs. And on this side, I only have room for one rung.
And you're always left with a wedge shape in the middle because the boards, no matter how straight they look, are always tapers. So this distance from here to here is 13 and over less than three feet, it goes out to 12. And that's a very typical of what will happen in any board.
And, if you can see the grain in the two outer pieces, you'll see that the long grain runs nice and parallel to the outside edges of the board. And that's what we want. We want straight, long grain.
So this is a really good example of how I would cut up a board like this. Same principle, we're going for long, straight long grain in the legs as well. Same thing for the slats. So we repeat that, this process on all parts.
If you're buying lumber that's been milled, you don't have a sawyer that you go to and buy boards out of a log, the first thing you have to choose is lumber that looks like it has straight grain.
That's really important.
Then secondly, when you get it back to your shop and you're milling it, you're going to mill it up for... breakdown of board into small parts. If the board does not have a live edge, you need to look at the long grain. And on one edge, depending on how wide the board is, at least on one edge, follow the grain, draw a line that's parallel to the grain, cut that off.
However, you can do it. And then use that as the reference surface for cutting subsequent part blanks.
Again, looking for straight long grain at every step.
Every step.
That's the first component of making a good joint - Straight, Long Grain.
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