Choosing the Right Adhesive
Cyanoacrylates (CAs) have become the adhesive of choice for most hobby and household applications. High quality CAs such as INSTA-CURE™, when used properly, form bonds that in many cases are stronger than the material that is being adhered. INSTA-CURE™ is a highly refined CA which, combined with its freshness, gives a guaranteed 2 year shelf life. CAs are reactive monomers that chemically link (polymerize) when pressed into a thin film. The very thin layer of water moisture present on most surfaces acts as an alkali, or weak base, which is the catalyst that results in bonding; however, the presence of detectable amounts of water usually degrades the performance of CAs.
Read More About How To Use Cyanoacrylates
Oderless CAs do not produce any fumes that irritate the nose and eyes. Odorless cyanoacrylates are formulated for use by those persons who have become sensitized or allergic to standard CA. Their use is recommended whenever sufficient ventilation is not possible. Odorless CAs have slightly less strength when compared to standard CA and are much more expensive. They can be used, however, on materials such as white foam that are otherwise dissolved or frosted by standard CA. They are non-frosting and do not attack white foam and are 100% safe for all foams.
The surface properties of some materials, such as being acidic or having very low moisture content, slow down the curing of cyanoacrylates. CA accelerator is formulated to harden CA in ten seconds or less. Accelerator allows large gaps to be filled in loose fitting joints and cures the excess CA that sometimes oozes out of joints so that objects can be handled within seconds without the worry of sticking one’s fingers to the parts. Accelerator makes the repair of household items much easier.
Debonders will soften cured CA. If parts are bonded incorrectly or your fingers are stuck together, a few drops of UN-CURE™ will dissolve the CA in about a minute.
If CAs are the cure-all for just about all bonding problems, you may be wondering, "Why do I need epoxy?" One primary reason is price. Epoxy costs are about one fourth that of CA. When large objects are being bonded, economics can be a deciding factor on choice of adhesive. The specific characteristics of epoxies also give them advantages in some applications. All our epoxies are mixed with a 50-50 ratio. Any scrap material or paper scratch pad can be used as a mixing surface. We have found, however, that the plastic tops to coffee cans work best due to their outer border and their flexibility, which allows the unused cured epoxy to be released and thrown away.
Squeeze out equal length beads of the desired amount of epoxy, then mix together thoroughly with a popsicle stick or scrap piece of material. In cold weather, epoxy takes longer to cure (too cold and usually they never fully cure) and becomes more difficult to get out of the bottle, especially if it’s less than 1/2 full. The epoxies can be heated in a microwave oven for about 10 seconds so that they flow easier. The heating process, with the caps off, also releases any moisture that can be absorbed by epoxies. Their shelf life, therefore, is virtually unlimited.
Acetone works as the best solvent for cleaning epoxy from brushes and unwanted surfaces before it cures. If epoxy gets on surfaces that acetone will attack, use isopropyl alcohol. We do not recommend any additives for thinning epoxies due to their effect on curing and overall strength. If thin epoxy is required, either use heat or switch to EX-SLOW™ or FINISH-CURE™. Epoxies bond best to clean, textured surfaces. Smooth, non-porous surfaces should be roughened with coarse sandpaper to improve adhesion.
A small amount of CA can be used in strategic locations to hold parts in place while the epoxies cure. The minute designations for epoxies refer to the working time, i.e., the time one has before the epoxies begin to set up after being mixed in a large mass. When spread into thinner layers, the working time in increased significantly (except QUIK-CURE™). Working time decreases approximately 25% at temperatures above 90 degrees F. Don’t panic if your skin comes in contact with either epoxy or CA.
While contact should be avoided, uncured epoxy can be washed from your skin with soap and water. Allergic reactions are rare. Cured epoxy and CA can be peeled off the skin and usually are gone after a full day of normal activity. UN-CURE™ will debond any body parts that get stuck together if a peeling action (never pulling) doesn’t part them.
Foam-Cure is a crystal clear semi-flexible silicone based adhesive for foam and other surfaces.
BSI’s IC-Loc™ threadlockers are anaerobic adhesives that cure in the absence of air, which occurs as a threaded fastener is tightened. They prevent the loosening of fasteners due to shock or vibration. Full strength is reached in 1-3 hours. IC-Loc™ is not compatible with most plastics. For best results, all surfaces should be cleaned before the application of IC-Loc™. IC-Loc™ should be store at temperatures above 45ºF and less than 80ºF.