Soy adhesive's developers hope to make it stick
New homes could soon be called the houses that soy built. Or at least helped hold together.
An adhesive made with soybeans — the versatile cash crop of many a Midwest farmer — is making its way into mills producing construction-grade lumber.
Medford's Jerry Scheid, a displaced timber worker who now works for a Michigan company called Omni-Tech International that helped develop the adhesive, is traveling around the country to pitch the product to mill operators.
— the year's end it should be in use in several mills in North America, Scheid said Thursday during a United Soybean Board press conference.
For now, only one mill is using it. Hampton Lumber of Willamina has begun producing finger-joint studs, such as the 2-by-4s commonly used in house framing, held together with the soy glue.
Scheid says few Rogue Valley mills deal in finger-joint products, so interest locally has been minimal.
The adhesive is a combination of soy and phenol-resorcinol-formaldehyde, the petroleum-based glue has been the industry standard for decades. Soy-based adhesives were widely used before World War II but were abandoned in favor of cheaper petroleum-based ones.
But the soy glue has become viable once again. Its advantage is that it can be applied to both dry and green lumber, promoters say. Petroleum glues work well only with dried wood and being able to bond wet and dry woods cuts costs for mills.
Mike Lipke, general manager of Hampton's mill, says that is what inspired his company to begin using the soy glue.
Historically, it's only been a viable product in the dry form, he says. Producers have had to dry the lumber before finger jointing it because of the limitations of the adhesives.
Hampton opened a new mill last year to produce finger-joint lumber from green wood; it added a second shift this spring. Lipke says finger-joint studs — basically shorter pieces that are glued together — have advantages over solid studs.
Contractors like the finger-jointed studs because there are fewer defects, he says.
Solid wood studs are more likely to twist or warp than finger-joint studs, Scheid says. When that happens after construction, it creates an expensive mess for the contractor who must redo the wall.
The finger-jointed wood stays straighter and the glue is stronger than the wood, he says.
Finger-joint studs cost $5 to $10 more per thousand, Lipke says, but the price tends to be more stable and works out to cents per stud.
The soy adhesive is manufactured by Hopton Technology of Albany. Early on, it was approved only for vertical construction uses such wall framing. In December, the Western Wood Product Association also approved it for horizontal uses — roofing trusses, door and window jam headers and the like.
This will further expand its use in the lumber industry, says Scheid.
Aside from the green wood advantage, finger-joint and other engineered wood products such as particle board also allow mills to use more of the log. Promoters also say the soy glue cuts the amount of petroleum-based adhesive needed by a half, reducing pollution and the reliance on a nonrenewable resource.
Finger-joint stud lumber — — a market estimated at 30 million board feet a year — is far from the only area the United Soybean Board is targeting.
We're hoping that the oriented strand board, the particle board and the plywood markets will be using this glue in the-not-too-distant future, says Gene Lewis, chairman of the soybean board's new uses committee.
The board also is promoting a soy-based foaming glue for plywood production and is working to develop soy-based waterproofing products, inks and solvents. Eventually, the soybean board estimates that such uses could consume 158 million bushels a year — — a big boost to domestic soybean farming.