WoodSense: Spotlight on IpeComments (1)
This article is from Issue 58 of Woodcraft Magazine.
The Brazilian construction lumber that wears like iron
Technical consultant: Larry Osborn
Although it’s often frustrating to woodworkers, the world’s lumber marketers of imported stock try to make wood choices easier for customers by creating a trade name with a familiar ring rather than use its scientific or common name. Take the subject of this piece, ipe (pronounced “ee-pay”). Its scientific name Tabebuia subspecies (spp), which may also include Handroanthus spp, applies to a few other woods with nearly indistinguishable characteristics. These include lapacho, Brazilian walnut, and guayacan. Ipe, pau lope, ironwood, and Brazilian walnut make up the trade names.
Due to ipe’s toughness and long life outdoors, the popularity of this attractive and dark olive-brown wood continues to rise along with its availability. Its use in construction, however, dates back decades. The Coney Island Boardwalk, which opened in 1923, was made of ipe. It has supported the foot traffic of millions, as well as the weight of garbage trucks and rescue vehicles. In 1960, it survived hurricane Donna relatively unscathed while nearby concrete was mangled.
History in woodworking
Durable and very hard, ipe has been and still is employed for everything from bridges to boardwalks, decks to docks, flooring, and railings. Figured ipe veneer, which resembles a dark Ceylon satinwood, becomes highly expensive doors and other millwork. Among the heaviest and most dense of commercial hardwoods, ipe also has a Class A fire rating, the same given to iron and steel!
In North America, woodworkers principally employ the beautiful wood in decks, railings, outdoor structures, and flooring. Because of its weight and difficulty to work, you won’t find ipe in furniture with complex joints, such as dovetail and mortise-and-tenon. You will, however, find online sites that sell lines of simply constructed ipe furniture for use both in the home and outside on the deck and patio.
Where the wood comes from
Where it grows best, in the Amazon region of South America, ipe is king of the jungle, towering 140' or more with trunk diameters to 6'. Logs are normally available in 100' lengths. Although Amazon-grown ipe is larger, the tree naturally grows throughout Brazil and has been planted in plantations there and in adjoining countries, as well as Central America and Mexico. This commercially valuable tree grows in many types of landforms–from marshes to riverbanks and ridge tops–and in such abundance that it is not an endangered species.
It’s a fact that…
Ipe weighs 69-80 lbs./cubic foot. It’s so dense that it sinks in water.
What you’ll pay
You probably won’t see ipe at smaller lumberyards and home centers, but you’ll find a wide selection of boards and milled parts at stores specializing in decking and flooring products and at online sites.
Ipe lumber has few grades, with Select & Better (S&B) the best. Three-quarter inch thick nominal boards in widths to 10" surfaced two sides (S2S) run about $12 per board foot. Decking is offered in two grade categories: “clear heart,” the best, and “rustic” (with knots and color variations) at about 35% less. All decking material is sold by the lineal foot, with 3⁄4" S4S 1×4s beginning at about $2.25 a foot.
Highly figured–and highly expensive–ipe veneer, destined for architectural applications, is available online. Here, you’ll find that costs vary widely depending on the degree of figure and sheet size.
How to select the best stock
Ipe is generally straight and close grained, although you might find some mottle and lace figured stock. Unfortunately, the interlocked grain, coupled with the wood’s hardness, will make the boards extremely difficult to work.
Heartwood color varies from reddish brown to yellowish olive brown to a dark blackish brown, and contrasting stripes are not unusual. However, the wood obtained from other trees in the genus or from differing growing conditions can offer stock that ranges from tan to a dark grey! So the best advice here is that when buying ipe in quantity, make sure it all comes from the same imported shipment to ensure similar color and grain. Also note that ipe, a jungle wood, doesn’t fare well in hot, arid climates, or indoors, where it can dry out and crack. Air-dried ipe with a moisture content of 14% to 18% has proven more stable than kiln-dried.
Working ipe in the shop
Ipe may be one of the most difficult woods to work. Its hardness and density resists sawing, planing, jointing, and routing. So if you want to do more than minimal machining, go to high quality carbide cutters and high-speed drill bits. Pre-drill pilot holes to avoid splitting.
Use a modest feed rate when sawing and light passes to remove material at the jointer or thickness planer. The interlocked grain can tear out when planing, so do it at a slight angle.
Ipe can also be difficult to glue up. Preparing mating surfaces with a swipe of strong solvent such as lacquer thinner will remove extractives. Then use an adhesive with a long open time so that it may absorb properly in the dense wood. (Note: In its traditional outdoor use, mechanical fasteners are the norm, not glue.)
Ipe sands relatively easily for such a hard wood and doesn’t splinter, but the resulting dust may cause an allergic reaction. Always wear a dust mask and long sleeves when sanding, and be sure to wash up afterwards.
Most ipe projects (decks) are left unfinished. Exposure to sunlight will lighten ipe to a pleasing grey, but color can be refurbished with a high-pressure wash. To reestablish the original color, you can also use ipe oil. The sawn ends of ipe boards can check if left unsealed. Here, consider a wax-based sealer, and reapply as needed.
Excellent article. Very informative.
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