EXCEL Polyurethane (PU) glues are excellent for all interior and exterior applications except gap-filling bonds where structural integrity is a factor. PUs can be used with a wide variety of materials and are specially formulated for deeper penetration and difficult glue-ups. They are primarily engineered to bond any two materials as long as one of them is porous, i.e., wood to wood, glass to wood, plastics to M.F., stone to bronze, etc. The user should be prepared to sacrifice some strength when bonding involves at least one non-porous material and should determine the amount of strength needed in these joints and perform tests to determine if the desired strength is present. Because of their foaming action and easy sanding quality, EXCEL PU glues are excellent where neat, stainable glue lines are desired. These PUs should not be used where strength is needed in gaps that appear in load bearing or stressed structures such as laminated beams.
SURFACES AND MATERIAL PREPARATION
EXCEL PU adhesives are water catalyzed, moisture curing products. Material moisture content should be between 8 and 20 percent. We recommend that the user dampen at least one of the gluing surfaces with water, even though moisture meter readings may be near the 8% mark. It is always best to dampen. This can be done by brushing, sponging, spritzing, or wiping with a wet cloth. Also, EXCEL PUs will perform best on surfaces that are a little rough. The PUs prefer a surface that has a “tooth” or “bite”. Whenever feasible, leave your gluing surfaces as rough as possible. For woods that dress out to a “slick” surface and for smooth surface materials such as glass, plastics, or metals, we suggest sanding the surface with 20-50 grit sandpaper or roughening the surface by some other means. Also, when working with oily woods, it is best to wipe the gluing surface with acetone, alcohol, or some other quick-drying solvent.
SPREAD (COVERAGE) RATE
Averages 1/3 to 3/4 oz. per sq. ft., with coverage needed on one surface only . When working with very porous materials, it’s best to apply a thin layer to both surfaces. For end-grain to end-grain bonds, we suggest using EXCEL XPRESS or EXCEL STRUCTAN. If using EXCEL ONE for this type application, apply a thin layer of glue to both surfaces and let them set for about 5 minutes. Then apply a second coat of glue to the surfaces.
Ideal temperature for applying glue is above 40 degrees F. Warm material and glue temperatures will accelerate drying and curing time.
Once a good mating of the two surfaces is achieved, stop the clamping. For clamping pressure on individual glues, refer to the product technical data sheets.
EXCEL glues are WATERPROOF, according to German Standard DIN 68 602 & EN 204 D4 commonly known as the boiling water test. These products can be used in underwater applications. For glueups that will be submerged indefinitely, the glue joints should be covered with a good quality paint, varnish or other coating.
TEMPERATURE RESISTANCE (Cured Glue)
Cured glue can withstand a temperature range from approximately -30 degrees F to 280 degrees F in glued joint.
Highly sandable, these adhesives will sand and/or grind to a powder without burning or softening, and will not clog sandpaper and sanding belts.
EXCEL ONE, EXCEL XPRESSand EXCEL STRUCTAN will accept stains better than any other type of glue. Additionally, these adhesives leave little or no visible glue lines, many times eliminating the need for coloring.
These glues can be painted over without affecting the glue nor the paint. This applies to all types of paint. Finishes and topcoats are compatible with these products.
Bugs and other insects reject these adhesives and will not attack the glue, even if left unpainted.
Inert solid. Once cured, these glues will not break down chemically and will not affect the environment.
SHELF LIFE AND STORAGE
Shelf life in unopened container is about 15 months. After opening, it is advisable keep the glue stored in a refrigerator or freezer. Cool, dry conditions will help keep glues fresh and usable. If stored in a refrigerator or freezer, we recommend removing them from the cold temperatures 2 to 3 days before usage, allowing the glue to reach room temperature or warmer. Low temperature glue will not affect bonding strength, but it will slow the drying and curing time.
The solvent for wet cleanup is acetone or better. However, since these glues scrape and sand so easily, we strongly suggest that the user simply allow them to dry and then remove any excess or glue spots by scraping or sanding.
NOT COMPATIBLE with Radio Frequency or Microwave Processes.