Sticking points Specialization sel ls adhesives

\ZEARS AGO, retailers could sell a I single adhesive for most construction needs. Nowadays, one sealant does not fit all.

With new building materials and challenging construction techniques the norm, the adhesives industry has recognized the need for project-specific bonding formulations.

"Through ongoing research and development, construction adhesives manufacturers are getting better results," explains Jeff Trattner, marketing manager for adhesive, caulk and sealant maker Macco. "They're formulating new adhesives----especially for new materials-that not only meet project-specific bonding needs, but are providing optimal performance given their typical project conditions."

Adhesives manufacturers are expanding their product lines to include more products which minimize use restrictions, such as temperature and weather, to ensure successful applications. The products have many formulas, developed for the various substrates the adhesives are meant to bond and for the environmental conditions in which they're applied, such as low temperatures or wet weather.

PROJECT.SPECIFIC adhesives help customers find the right producl and improve pertorman@.

"Subfloor and deck adhesives for exterior use contain anti-oxidants to help guard against aging and weatherizing," says Macco's senior adhesives chemist, Glen Kaszubski. "The solvent in this type of adhesive will penetrate wet, frozen and treated lumber."

Adhesives for paneling and moulding are designed for greater grab and sufficient working time, usually about l0 minutes. "Using an adhesive while installing paneling makes the job easier since it holds the panels in place while you reach for and apply metal fasteners," he says.

Better performing products also have been formulated as a result of environmental and health concerns. For example, in compliance with VOC standards, multi-purpose adhesives have been developed featuring lowsolvent, high-solids formulas that provide greater gap filling and adheslon,

While the general definition of a solvent is an ingredient that makes an adhesive wet-which means that water can be referred to as a solvent in the case of water-borne adhesives-the adhesives industry usually means fastevaporating chemicals. Other ingredients in adhesives are pigments and binders (resins and rubbers), the materials that give the product strength, adhesion and flexibility; and fillers, which provide consistency, color and sag resistance.

"While water-borne adhesives have been around for decades and have withstood the tests of time (in fact, they perform better than solvent-based adhesives in ceramic tile applications), they do not work as well as solventbased adhesives in some instances," Kaszubski says. "This is for two main reasons. Water-based adhesives can walp some substrates, like wood, and when applied between two non-porous substrates such as plastic, the water has no place to go and won't dry. Conversely, a solvent will travel to the surface to dry."

Since the reputation of your contractor customers and, subsequently, the success of your business rely on how well their projects hold up, ensure that building professionals consider the following when selecting adhesives: the ability of the product to bond the material an{ the length of the product's service life.

Additionally, they should look for the America4 Society of Testing Materiafs (ASTM) standards on the product label to confirm that the product will do what it claims.

According to Trattner, workmanship is just as important as selecting the right product for a particular application. "The biggest challenge manufacturers have today is communicating to building professionals that they need to read labels carefully," he says. "Professional builders and remodelers typically use products the way they've been shown, which generally, is a great way to learn. But with products advancing nearly every day, the application that worked l0 or 20 years ago may not work today. Field failures are most often attributable to using too much or too little adhesive, or the wrong adhesive for the application."

He predicts that construction adhesives of the future will remain projectspecific and become even more durable and safer to use.