Contact Adhesive Is Unlike Any Other Glue
Contact adhesive... a glue with a mission
Contact adhesive... also fondly known as "contact cement"... is a special adhesive for a special purpose. When spread on a surface, it dries by the quick evaporation of a flammable solvent. Like other adhesives, it sticks things together. But it has a unique characteristic no other adhesive shares. For a period of time after it appears to be completely dry and no longer tacky, it will still stick to itself with abandon! This makes it an excellent adhesive for gluing together materials that are nonporous.
In your home, the most common use of contact adhesive are plastic laminate countertops in kitchens and bathrooms. Envision the perplexing problem solved by this product. You have two very wide pieces of material and both have limited porosity... particle board (the standard countertop substrate) and plastic laminate. Virtually every other adhesive would fail because the glue would never dry... the moisture or solvent could not escape from between them. Or drying would take so long that special clamps would be needed to keep the materials in contact for the lengthy drying period. Since the contact adhesive is already dry before assembly, this problem is... well... not a problem!
Once the contact adhesive is applied to both surfaces and allowed to dry, the actual assembly of the two parts takes but a few minutes, and the countertop is useable immediately! Of course, there is no room for error with contact adhesive. Once it sticks, it is stuck for good! Disassembling items glued with contact adhesive usually requires damaging one or both of them. And does it stick fast... momentary contact is all that is needed for adhesion, making positioning and planning vitally important for success!
Contact adhesive can be finicky when not used correctly.
Most problems with contact adhesive failure are caused by:
1) not allowing the adhesive to dry fully before assembly
2) waiting too long before assembly
3) applying too thick a coating of adhesive
4) not applying enough adhesive.
When used on a porous or semi-porous material such as wood or plywood, a first "priming" coat of contact adhesive may be needed to preseal the material. Otherwise, some areas may absorb too much adhesive to form a strong bond. This prime coat is followed by a second gluing coat. Following the label directions concerning drying times, application thickness, and using the proper tools will keep you on the right track!
Contact adhesive is available in the traditional solvent-based formula and a newer water-based formula. Solvent-based contact adhesive dries in under 15 minutes but releases a highly flammable solvent into the air. Precautions must be taken to assure adequate ventilation to prevent accidental ignition of the fumes. Read the label for all precautions! Also, the article Level-Headed Low Down On Loose Laminates And Crappy Countertops has more on this topic.
DAP manufactures both solvent-based and water-based contact adhesives, and their products are widely available in hardware and home stores.