Woodsense: Spotlight on ElmComments (0)
This article is from Issue 53 of Woodcraft Magazine.
The once-common commercial hardwood we almost lost
By Pete Stephano
Technical consultant: Larry Osborn
Elm may not be as conspicuous and popular as are many of the “cabinet class” wood species in modern-day furniture making and woodworking. After all, the three most common North American elms represent only about three percent of all commercially available domestic hardwoods. That’s mainly due to the fast-spreading Dutch elm disease of the 1950s and 1960s that devastated millions of stately elms from the East Coast to the Midwest as well as in Great Britain and Europe, nearly wiping out the species. Since that crisis, disease-resistant elms have been botanically created and reintroduced to American woodlands.
The domestic elm species represented as lumber in the U.S. include American or gray elm (Ulmus Americana), red elm (Ulmus rubra) also known as slippery elm, and rock elm (Ulmus thomasii). Great Britain’s most prominent is English elm (Ulmus procera), which is called Carpathian elm in continental Europe.
No matter the individual elm species, the stock shares similar qualities, except that rock elm is harder and heavier. Flatsawn elm boards can sometimes exhibit a distinctive “W” or bird-feather grain patterns. The wood has open, coarse grain much like white ash that is most often interlocked, making it somewhat difficult to work. Although only moderately strong, elm bends easily, is shock resistant, and can take abuse.
It’s a fact that…
Elm’s interlocked grain adds difficulty to machining, but to some users, it was a blessing. In early America, tough elm was a favorite material for horse barn floors. The grain showed impressive resistance to the wear of horses’ hooves!
History in woodworking
Elm’s woodworking roots go back thousands of years. The first written references to elm occur in the Mycenaean Period of early Greece–lists of military equipment mention the wood’s use in chariot parts. Centuries-old bows found in Europe employed elm–even the famed English long bow was occasionally crafted of it when bowyers lacked the preferred yew. Elm was even favored for the keels of English sailing ships; in fact, much American elm was exported for that very purpose.
Surprisingly, elm resists decay when in constant contact with water, so bored-out elm (along with hemlock) logs ended up as below-ground city water pipes in 18th-century Europe and America.
In the United States, elm’s early usage included wagon wheels and hubs, barrel staves and hoops, children’s wagons and sleds (it won’t easily splinter), agricultural implements, tool handles, hockey sticks, boxes, and even baseball bats. In contemporary applications, the wood’s ideal for steam-bent chair parts as well as tabletops and cabinets.
Where the wood comes from
In North America, two of elm’s principal lumber species– American and red–grow from the Midwest to the East Coast and southern Canada to northern Florida. The smaller rock elm has a range roughly limited to the northern parts of the Great Lakes states.
English elm grows throughout Great Britain and the temperate regions of the continent. Some elm species also grow in Asia and Australia. Due to precautions against the transmittal of Dutch elm disease, you’ll only find English elm burl veneer being sold in the U.S., and it’s expensive.
What you’ll pay
The National Hardwood Lumber Association (NHLA) grades for all elm except rock elm are somewhat complicated, but you can expect to find lumber graded from FAS (first and seconds, the highest) to Common grades (the lowest).
For rock elm, NHLA grades are similar to those for hickory and pecan in that they allow for narrower 4"- and 5"-wide boards compared to the minimum 6"-wide boards in the best grades. A 4/4 (one inch thickness) board of FAS elm will cost between $4 and $5 per board foot, with many sellers not differentiating between red and American elm. The much heavier and harder rock elm, though, is usually sold apart from the other elms and can cost a bit more. You may only be able to find rock elm lumber close to where it grows. Only some local dealers in the range carry gray or red elm lumber so be sure to call around before wasting gas. Don’t expect to find it at big box stores and small urban lumberyards.
Paperbacked, rotary-cut elm veneer, both American and red,
is available by the square foot (about $5) or 4× 8' sheet ($170) in 10
millimeter thickness. Thicker veneer (22 mil.) costs more as does flat sliced
and quarter cut. Scarce Carpathian elm burl veneer may top $500 per 4×8' sheet
in 10 mil. thickness.
Finally, while English and Asian elm is made into plywood and sold in Europe and Asia, you’ll not find elm plywood made and sold in the United States.
How to select the best stock
Elm varies slightly in color from species to species. American and rock elm have a grayer cast to their natural tan heartwood color while red displays a warmer orange-red color. The sapwood of all three is a very light tan. American and rock elm lumber can show some staining, which detracts from appearance. And all elm boards can have tiny bird pecks and pin knots, both of which are allowed in grading because neither affects the wood’s performance.
When selecting boards, be discriminate concerning quality. Improperly stored elm during seasoning may show warp and/or twist that may result in working problems and waste. After purchasing elm boards be sure to store them in stickered fashion off the floor with evenly distributed weights atop the stack.
Working elm in the shop
American and red elm species rank half as hard as sugar maple, and rock elm nearly as hard. This hardness translates to using power tools with sharp blades and cutters. Because elm contains interlocked grain, it makes splitting the wood difficult. Ripping, however, poses no problem. On the other hand, shaping with a router, jointing, and planing can prove challenging. Limit tear-out or chipping by making very light passes and using backers when cutting across the grain.
While pre-drilling pilot holes for screws is necessary, you’ll discover that elm bonds well with all adhesives. The wood also sands easily. Using progressively lighter grits will enhance its natural luster. Finally, elm’s interlocked grain means taking a little more time and care when carving or turning it.
Deciding on the right finish
Due to its open, coarse grain (think red oak and white ash), a glasslike top finish requires filling the pores. But other than that, the wood takes all dyes, stains, and finishes equally well.
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