Archive for the Category ◊ Wood ◊

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• Sunday, September 23rd, 2018

Khaya

Next up is khaya. The wood available to us may be any of four species in the Khaya genus: K. ivorensis, K. grandifoliola, K. anthotheca, and, less so, K. senegalensis. Ask the guy at your lumber yard what species he’s selling and he’ll probably look at you the same way we look at an 88° try square, even if the importer had kept the species distinct. In fact, you’ll probably create confusion by asking for the “khaya” bin because it is more commonly referred to as African mahogany.

And so, this is the only wood comparable to genuine/true mahogany (Swietenia) that generally bears the “mahogany” name. Botanically, it is in the same family (the next major grouping above genus), Meliaceæ, as Swietenia. It comes to us from West African countries.

Just like true mahogany, when African mahogany/khaya is good, it is indeed a very good wood. The problem is that I have had just as much frustration with inconsistency in density and color in khaya as with true mahogany. There is variation among species, but also with the geographic source of the tree, and the local conditions in which it grew. Therefore, as a practical matter, I suggest that you not be too concerned with the provenance of the wood, but evaluate each board on its own merits. Khaya is about half the cost of true mahogany, and there is some great stuff available.

Some khaya is less dense, and quite light in color – an uninspiring pale pink hue. The flatsawn wood looks particularly anemic. When quartersawn, these boards often have a hairy surface that can be difficult to finish. They come off the planer with hairy rows that are hard to tame with planing, scraping, or even sanding.

I try to avoid these boards and instead look for darker, denser boards. Many quartersawn khaya boards exhibit a fairly coarse, beautiful ribbon stripe. The boards in the photo at top are a good example of dark khaya with great ribbon stripe. Look how nice it finishes:

African mahogany

More quartered African mahogany:

Khaya

The color below is a bit more red but also very nice:

African mahogany

Good flatsawn khaya is also very worthwhile. In some case, it is difficult to distinguish from high quality true mahogany. In general though, I’ve found that true mahogany’s legendary chatoyance is harder to find in khaya.

Unfortunately, khaya seems to be quite susceptible to the dreaded compression failures that I discussed in reference to mahogany in the previous post. With the possibility of these defects, as well as the great variation in the other properties of khaya, I suggest buying your boards S2S planed or hit-or-miss planed, if possible. Look them over carefully.

Coming up: sapele and others.

Category: Wood  | Tags:  | 2 Comments
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• Saturday, September 15th, 2018

mahogany

Fasten your seatbelt as we ride through the world of mahogany! Our tour will be mostly about woods that are similar to mahogany, and sometimes referred to as “substitutes” for it, but are better considered on their own merits.

We start our journey with “genuine mahogany,” aka Swietenia macrophylla, big-leaf mahogany, Honduran mahogany, Central/South American mahogany, or if you want to live and buy dangerously, just call it “mahogany.” Just the name sounds, you know, classy. People, including people who buy furniture (such as you might build) but know nothing about wood, are almost always impressed by “mahogany.”

Note that in the rear-view mirror is Swietenia mahogani, aka Cuban mahogany, the best of them all, once used for building ships and furniture, but long since essentially unavailable. You might find a bit of it for sale that was rescued from the occasional tree downed in a storm in south Florida, and there is a plantation operation on a South Pacific island. I once read that it works like “cold butter,” and having had a tiny piece of the stuff some years ago, I can confirm that description.

But back to S. macrophylla. When it’s good, it has a lot going for it. Boards with good density and color are a pleasure to use in your projects. It usually planes easily on the flatsawn surface, while the quartersawn surface often exhibits attractive “ribbon-stripe” figure due to interlocked grain. This is difficult to plane but quite manageable with scraping and sanding. The wood is soft enough to saw and chisel easily but firm enough to hold detail.

The stability of mahogany is legendary. Radial shrinkage is 2.9%, tangential 4.3%, yielding an excellent T/R of 1.5, and paltry volumetric shrinkage of 7.5%.

Then there’s the chatoyance – that wonderful shimmery gleam, lovely but not overpowering – that mahogany does so well. You know, classy. A shellac and wax finish looks great.

Unfortunately, big-leaf mahogany is a big pain in the neck. Why? First, because it is expensive. I cannot find even the drabbest mahogany for less than $10 per board foot. Yet it is extremely variable in quality. Some boards in the bin will have that nice density and color, while others are junk wood – light in color and density, or often with defects. In fact, I suggest avoid buying mahogany in the rough; look for S2S or hit-or-miss planed stock.

In the photo at top, all three boards are genuine mahogany. Yup, the real thing. The top one resembles sapele (more on that in an upcoming post), the middle board is what I consider nice flatsawn mahog, and the bottom one is genuinely trash wood, as far as I’m concerned.

The most notorious defects are compression failures, sometimes called “windshakes.” These are jagged cracks across the grain, usually through the full thickness but not the full width of the board. The fibers are broken, rendering that part of the wood useless. It occurs in the tree from severe wind forces, snow loads, or, what I suspect is mostly the case with mahogany, when the tree is felled. Beware: this defect is very difficult to notice in rough boards, where it lurks to disappoint you when you bring the wood home and plane it.

compression failures

See the defect in the board below? No? Neither did I before I took it home.

hidden compression failures

Here is the other side of the board, with the compression failure clearly visible after I skimmed it on the jointer. The defect goes through the full thickness of the board.

compression failure

S. macrophylla is listed in CITES Appendix II, and on the IUCN Red List as Vulnerable. We are probably encountering mostly plantation grown wood, and the quality is uneven at best.

And so, regrettably, mahogany is nearly off my list of good options for wood. Next, we’ll look at a common alternative, Khaya, aka African mahogany. There’s that word again.

Category: Wood  | Tags:  | 3 Comments
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• Friday, June 22nd, 2018

wood rack

What is the most likely pitfall to cause your next woodworking project to fall short of your hopes? Answer: injudicious choice of wood.

OK, sorry, I’ll state it positively: each project has the potential to be greatly elevated by smart choices in choosing and using wood. But let’s look more closely at this matter.

On the one hand, there is knowledge of wood in general. This includes things like wood movement, strength properties, and grain. As you design a piece, you choose species of wood, and then, much as an engineer, use that knowledge to work out the details.

However, wood is not clay, steel, or plastic. Each board is the product of the incredible diversification of the biological world. For this reason, to be really successful at using wood, you must be intimately familiar with the species of wood that you are using. Go beyond your designer and engineer mentalities to that of a biologist.

For any species, there is so much to be cognizant of when choosing the specific boards and deciding how to make the best use of them. Where was the tree grown? How was the log sawn? Were the boards air-dried or kiln-dried; were they steamed? How does this affect the working properties and color? What defects is this species prone to? How will the color change over time? And on and on.

Let’s take cherry as an example, but the important point is that every species has its own large set of potentials and quirks. Cherry’s generally wide availability and easygoing workability can lull you into complacency.

Of course, cherry darkens with time and exposure to light to produce that legendary brownish, brick red color, but this is accompanied by a varying amount of softening of the original figure. Some people like this, others may be disappointed. Some boards have more distinctly etched figure, sometimes with a greenish tinge, and seem to retain it better. Speaking of figure, I find the quartered surface of most cherry to be somewhat disappointing.

More vexing is cherry’s tendency to produce a blotchy effect with some finishes, especially oil. If a board has the tendency to blotch, it is virtually impossible to fully avoid, but it varies widely among boards, so, again, the key point is to recognize this and choose wisely.

Gum streaks are a defect to the eyes of some woodworkers, others may like a few. I’ve also encountered some cherry boards that have fairly heavy gum streaks along with an unappealing “dirty” look that is hard to detect in the roughsawn state. As for the lighter sapwood, some reject it entirely (accepting only “all red”) but some may like the effect, such as with live-edge boards. Cherry from northwestern Pennsylvania is said to be the best available.

When choosing curly cherry, it is a mistake to suppose that it is similar to curly maple. Curly cherry is essentially very blotchy cherry in a nice pattern. Thus, cherry that is sold as “curly” but contains only minimal curl looks poor, and you’ll pay more for it. I’ve also found that curly cherry that is sanded or scraped never looks quite as good as when it is handplaned to the final finish (and that can be tricky pull off), even when a film finish is applied. Curly cherry is quite a different matter than curly hard or big-leaf maple.

I could go on. It sounds like choosing players for a baseball team – good batting average but can’t hit left-handers . . .

I enjoy using a lot of different species of wood, and I’ve paid the price, literally and figuratively, for sometimes falling short in this area. On the other hand, knowing wood really well is a joyful and fulfilling part of the craft, well worth deeply exploring.

Category: Wood  | One Comment
Author:
• Friday, May 04th, 2018

wood sound

Have you listened to your woodwork lately?

We are all cognizant of the visual beauty of wood, its tactile warmth and texture, and the memorable scents produced while working at least some species. But here is a reminder to tune in to the sweet sound of wood.

Notice the resonance when closing a lid or drawer made of solid wood. Or the sound of a ceramic bowl placed on a solid wood table. Compare those to the discomforting clamor of melamine-coated particleboard. The sound of real wood just seems like the ease and contentment of home.

Our lives are filled with the cacophony of sheet metal, glass, plastic, and concrete. How welcome is the comforting sound of solid wood.

We woodworkers create in a very special material.

I recall even early in my youth intuitively sensing that there was something special about wood, and some of that came through its sounds. I remember particularly a sturdy solid wood truck in the kindergarten room and the sounds of loading it with solid wood blocks. That rig had a dignity unmatched by plastic stuff.

Of course, the sound produced from wood reaches its full potential in musical instruments. Remarkably, even with all the advances in materials science, the best acoustic strings and woodwinds are still made from wood. And some of that acoustic magic is present in the solid wood furniture and household objects that we make.

Take notice and enjoy!

Category: Wood  | 4 Comments
Author:
• Friday, June 30th, 2017

sensing wood moisture content

Can you really sense, with any practical utility, the moisture content of wood simply by touching it? Yes. Let’s take a look.

An object feels hot or cool to the touch of your hand because of the flow of heat between your hand and the object. For example, an object feels relatively cool because it is drawing heat from your hand.

Remember how mom or dad could tell if you had even a bit of a fever just by touching your forehead?

Consider wood. The heat flow depends on several factors. The variable that we want to isolate is the moisture content (MC) of the wood. Wetter wood will draw heat from your hand faster and thus feel slightly cooler.

We want to keep these other factors constant:

  • The wood species – density is the key. Denser wood will transfer heat faster.
  • Surface texture. The greater contact of a smooth surface will transfer heat faster than a roughsawn surface. To a lesser extent, a diffuse porous wood such as cherry transfers heat faster than a ring porous wood such as oak.
  • The temperature of the wood, especially relative to your skin temperature, of course, affects heat flow. Heat energy flows from the warmer object, usually your hand, to the cooler object, usually the wood.
  • The surrounding temperature and moisture conditions will likely affect your perception of hot and cool.

Those four other factors are constant in the typical situation of sorting through boards at the lumber dealer – a particular species, roughsawn, at the temperature and surrounding conditions on that day.

So, can you sense differences in MC based on how cool or warm the wood feels to the touch of your hand? I think I can. No, I cannot tell the difference between 8% and 10%, but with the aid of a pinless moisture meter, I have shown myself that I can tell the difference between, say, 8% and 14%, and even closer than that. Every time? No, but reliably enough that I can use my sense of touch to quickly sort through boards of one species at the lumber dealer and help me make choices. Larger differences are more apparent. This also can alert me to certain situations, such as a poorly stored 10/4 board that is much wetter on one side than the other.

The differences I am sensing are relative, not absolute, but that is what I am concerned with as I sort through the piles. It is even possible to “calibrate” my hand for absolute measurements for a particular pile of wood by taking a couple of readings with a pinless moisture meter, and correlating that with what I feel, but I wouldn’t rely on that and it is not what I need.

I am not suggesting you discard your moisture meter. I also understand that the “measurement” is shallow. And I’m not going to put my lips on the wood; that’s weird. Yet, with some awareness and very little practice, you can get a pretty good sense of the relative moisture content of boards just with your hands.

What’s your sense of this?

Category: Wood  | 4 Comments
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• Tuesday, December 20th, 2016

inlay banding

Here is another product that I think you will appreciate knowing about, which I alluded to in the previous post. It is inlay banding made in North Carolina by Matt Furjanic, sold on his website Inlay Banding.

This is beautiful material made with precision from highly select, solid hardwoods. Only some of the narrow outer stripes are made from veneers. Most of the bandings are about 1 mm (3/64″) thick – enough to work with as real wood instead of as curled up, long potato chips like some other bandings. Lengths are generally 36″.

These bandings consist of all face-grain wood, not end grain, so they look great and finish beautifully and predictably. This also makes them easy to work with. They glue well into the slot and pleasantly scrape flush to the surrounding wood. By the way, scraping works much better than sanding for flushing, especially for banding containing ebony, which tends to muddy the lighter woods if sanded.

They come in a wide selection of patterns, mostly low-key. These will enhance your projects and not be obtrusively glitzy.

I knocked together a long plywood box to safely store the bandings in my shop:

storage box for inlay banding

Matt also sells guitar bandings, stringing and stock for line-and-berry work, federal shaded fans, and very select thin stock for making your own inlay materials. He also does custom work, and sells some great looking boxes, which, of course, feature inlay bandings.

This is the best inlay banding material I have found. This review is unsolicited and uncompensated. The last paragraph of another post explains why I present these reviews.

One more thing. Some woodworkers may balk at including woodwork made by someone else in their pieces. This makes no sense to me. Virtually all of our work contains elements made by someone else, such as hinges, handles, locks, other hardware, and glass. And don’t forget the finishing materials. It is how you use these materials that counts. Even aside from this, we have had lots of help, starting with the guys who cut down the tree, drove the trucks, milled the log, and so forth. I am happy to add expertly-made inlay such as this to my work.

Author:
• Sunday, November 13th, 2016

crosscutting lumber

So often I bring to mind the admonition from James Krenov in the Fine Art of Cabinetmaking, “Cross-cutting should always be preceded by careful thought.”

When divvying up rough stock for a project, it is those early crosscuts, often particularly the very first one, that so much determine the successful use of the wood, and in turn, the entire success of the project.

We tend to let our guard down at this early stage because the lumber is rough and the cuts are rough, so it seems like little could go wrong. We are not naturally in a precision frame of mind as when approaching joinery work. Moreover, it seems like there is so much wood now, maybe much more than needed.

But beware, these early breakdown crosscuts will in large part dictate the figure and color matching of the wood in the finished piece. After The Crosscut – the one that felled the tree – and the sawing and drying of the boards, these initial crosscuts in your shop are critical to the efficient use of your expensive wood.

As with most matters in woodworking, winging it is not often rewarding. So think it through with the measured drawings nearby, and tape measure and chalk in hand. Be alert. Look at the wood, study the figure and grain, find the defects. Make thoughtful decisions.

The eternal woodworking quest for a board stretcher remains unfulfilled, so I heed the advice of the master.

Category: Wood  | 2 Comments
Author:
• Monday, October 31st, 2016

live edge wood

The rustic look of furniture featuring a live edge board currently has wide appeal, as it seems to draw a response even from those people who otherwise pay little attention to the intrinsic beauty of wood.

Here are two uncommon options for designing with live edge wood: let the natural “path” of the board’s live edge guide the whole structure of the piece or, similarly, determine the shape of just other components of the piece. The live edge can be followed loosely or closely.

In the small table above, the front rail in ash follows the general sweep of the live edge of the walnut top. As with other pieces, I carefully striped the bark and prepared the live edge to retain almost all of the organically interesting wavelets. Thus, the live edge follows the peaceful flow of the ash rail but also presents an exciting contrast in form.

The rail construction is a bent lamination. I worked out the angles and joinery in a full size drawing because they were trickier than I first imagined.

In the wall shelf below, I again preserved the undulations as well as the fine ripples in the curly big-leaf maple board. The pear drawer front is a rare specimen with exquisite flame-like heartwood. As seen in the second photo below, I matched its contour to the waves in the maple’s live edge.

live edge wall shelf

live edge design

The photos of this piece are a bit weak but the actual piece projects a distinctly “live” feel. I really let the wood “design” the piece.

These are just some ideas for working with live edge wood. Though they involve a lot more trouble in construction, the wood is inspiring and sustaining.

wall shelf with drawer

Category: Wood  | 5 Comments