Q&A: Job-Site Glues

Q&A Jop-Site Glues

Glue Glossary

Acrylic glue

is the best glue for melamine. This water-based glue is technically EVA (ethylene vinyl acetate). Two EVA glues are Roo Products' RooClear and Franklin Internationals' Titebond Melamine Glue. Although EVA can be used on many materials, including vinyl, rubber, metals, stone, and plastic, it is rarely used on anything but melamine, because it forms a soft bond with a tendency to creep.

Adhesive caulks

like Gloucester's Phenoseal can be used to bond wood, fiberglass, carpeting, vinyl, tile, and concrete. Adhesive caulks are waterproof and do not require clamping. They are not as strong as most glues and are more expensive than most construction adhesives. Typical applications include attaching kitchen backsplashes and exterior trim. Construction adhesives are thick glues that come in tubes and are applied with a caulk gun.

Construction adhesives

can be either solvent-borne or water-borne. Typical construction adhesives include Liquid Nails and OSI's PL400. A wide range of construction adhesives are available for a variety of applications. They are used to join wood, metal, plastics, and rigid foam to wood or concrete.

Contact cement

is most often used to bond plastic laminate to a substrate like particleboard. However, contact cement can also be used to bond wood, hardboard, plaster, plastics, metal, drywall, and fiberglass. The bond is heat-resistant and water-resistant. To use contact cement, both surfaces are coated and allowed to dry until they are tacky. The surfaces are then pressed together, and they bond immediately without tight clamping. Because contact cement contains a flammable solvent, it cannot be used near an open flame.

Cross-linking PVA

glue is a weather-resistant type of yellow glue. Cross-linking PVAs are very strong and versatile. Titebond II and Elmer's Weather-Tite are cross-linking PVA glues. Cyanoacrylate glue, also called super glue, can bond a wide range of materials, including wood, veneers, rubber, plastics, and metals. Among its disadvantages are its high cost and low tolerance for shock. For an instant cure, add an accelerator like Zip Kicker. Cyanoacrylate is a good choice for quick repairs -- for example, to repair a raised sliver on a cabinet or door. Epoxy glues have two parts, a resin plus a hardener. They cure by an exothermic chemical reaction. Epoxy glues are expensive but form a very strong, waterproof, heat-resistant bond. Epoxy is excellent at filling gaps and requires only light clamping. Epoxy can bond a wide range of materials, including wood, fiberglass, concrete, glass, leather, and plastics. Epoxy is often used for anchoring masonry fasteners and repairing rotten wood.

Hide glue

gets its strength from animal protein. It is made from bovine leftovers like hide, hooves, and bones. Hide glue's bond is not very resistant to moisture. Franklin's liquid hide glue is more convenient to use than traditional powdered hide glue, which needs to be heated for use. (Incidentally, the bull logo that Borden uses on Elmer's Glue-All has no connection to the production of hide glue. Elmer the Bull is a substitute for his mate, Elsie the Cow. Elsie was Borden's logo for its original glue, which was a casein glue made from skim milk.) Hot-melt glue comes in solid sticks that are heated in an electric glue gun.

There's more than one way to skin a cat: Although a bottle of yellow glue and a tube of construction adhesive will handle a great many gluing needs, there are times you might want to choose a special glue from the wide range available.

Hot-melt glue

is inexpensive and has gap-filling ability. It cures almost instantly and is more often used for temporary than permanent bonding. Polyurethane glue is often used for exterior woodwork. It has almost no solvent content. It cures by chemical reaction with moisture present in the air or the materials being glued. As it cures, it foams, helping to fill gaps.

Polyurethane glue

can be used with wet wood and forms a strong waterproof bond. It stains the skin and is difficult or impossible to clean up. Gorilla Glue and Excel Glue are typical polyurethane glues.

Polyvinyl acetate (PVA)

glues are a category of glues including common white and yellow glue. PVA glues are inexpensive and nontoxic.

Resorcinol glue

is a two-part glue containing a liquid resin and a powdered hardener or catalyst. Like epoxy, resorcinol cures not by drying but by an exothermic chemical reaction. Resorcinol is a very durable, strong, heat-resistant, waterproof glue used for exterior applications. It has long been used for making wooden boats and airplanes. Among its disadvantages: It is relatively expensive, requires long clamping time at high pressure, and leaves a dark purple stain on wood. DAP Weldwood sells resorcinol glue.

Silicone caulk

can be used as an adhesive. Silicone is suitable for exterior use and can be applied at temperatures as low as -55¡F. Silicone can solve awkward bonding problems -- for example, it is used to attach small access ramps to raised door thresholds.

Urea formaldehyde glues

come either as a powder that is mixed with water (for example, DAP Weldwood plastic resin glue) or as a two-component glue (for example, Unibond 800). The glue develops its bond when urea and formaldehyde are mixed. Urea formaldehyde glue is very strong and inexpensive; however, it can only be used above 70F and requires tight clamping.

White glue

, which is a polyvinyl acetate glue, is a common inexpensive wood glue. Elmer's Glue-All is a typical white glue. Although white glue does not form a waterproof bond, it is cheap and very strong and is suitable for many interior applications. Unlike yellow glue, which has a shelf life of about a year, white glue will stay fresh for years in a sealed container. White glue cures by loss of moisture. One of the disadvantages of white glue is its tendency to gum up sandpaper.

Yellow carpenter's glue

, like white glue, is a type of polyvinyl acetate glue. Typically, yellow glue is thicker and tackier than white glue. The use of yellow dye to distinguish improved varieties of PVA glue from the earlier white varieties is a manufacturer's convention; the color of the glue is no indication of its quality. Most yellow glues are more resistant to solvents and heat than typical white glues. They are also less likely than white glues to clog sandpaper. Titebond is a typical yellow carpenter's glue.