A guide to the different types of adhesives in use in hobbies, crafts and modelling today, their advantages and pitfalls with tips on their use.
Adhesives are no longer as simple as they used to be. Good old "glue" has developed greatly in recent times and any hobby enthusiast, especially modellers, will use a range of different adhesives according to the materials they are working with and the particular requirement they have to deal with.
Forty years ago you were unlikely to come across any adhesive other that that thick white paste used in junior school or a bubbling concoction of boiled up horses hooves kept on a low heat by carpenters and joiners. Nowadays, modern adhesives are all based on advanced chemical process. The most common adhesive you will come across today is known as Super Glue to the general population but CA to the modeling community.
Cyanoacrylates, commonly known as 'cyano' or CA in the modeling world and 'Instant' or 'Super' glues to everyone else is good for wood, plastic, metal, glass, ceramic, fabric, rubber, fiberglass, carbon fiber or combinations; in fact most things in everyday life as well as in modeling. CA adhesives come in different thicknesses or viscosity and in different formulations according to the material it is to be used on. That's the hazard as we all get used to their 'wonderglue' properties and expect them to stick just about anything.
In fact, for greatest effectiveness most adhesives are specifically formulated to stick a particular material. So be careful to use the right one as the wrong choice can either be ineffective or worse, literally melt whatever you are working on. If that is a model that has already occupied many hours of your time you are not going to be very happy! Follow the model manufacturers' recommendations about the type of adhesive to use or if there are no recommendations available then your local hobby shop should be able to help.
Modeling club mates can also be invaluable as sources of advice - even if for nothing other than to tell you what not to use based on their own sorry experience. Alternatively, spend a little time researching on the internet (just put adhesive +[the material you are sticking] into your favourite search engine. Adhesive manufacturers are these days providing more technical information about their products and the best way to use them. If in any doubt follow that old standby rule and 'test on a small area first'.
CA comes in different viscosities. The thinnest viscosity of CA is excellent for gluing balsa, that most traditional of modeling materials, as the very thin glue can be applied to the edge of the join and will penetrate both the join and the surrounding balsa wood to create a strong bond. The downside of this very thin viscosity is that it cures or 'goes off' very quickly, literally in seconds.
If you are really in a hurry then an 'accelerator' or 'kicker' will speed up the curing of the top surface of the adhesive instantly and then progressively cure the remainder. Alternatively, apply CA to one surface and spray kicker on the other before mating them together for a really fast bond. This is useful when making running repairs out at the flying field.
The hazard of all this miraculous sticking power is when it all goes wrong and you end up with adhesive in places you never intended it to reach, leaving you glued to your own model, the table or anywhere else you put your hands. That's when debonders come in useful as they can remove cured CA glues from skin, work surfaces, most plastics and model finishes. Naturally, it is best to have these at hand as it is too late to go trotting down the model shop to buy some when you are already glued to the kitchen table.
For more substantial joins, epoxy resins come as two part adhesives, one part resin and one part hardener that have to be mixed to become active. Vibration resistant and fuel proof, epoxy is perfect for modelers dealing with engines for fire wall and engine mount installations, and for attaching bulkheads and formers in epoxy glass fuselages. It comes with different curing times for example; 5 min, 30 min or 1 hr which are used according the result required. Since epoxies cure by an exothermic chemical reaction, meaning that means they give off heat, and heat can speed the cure of epoxy, mixing more than you need can result in it hardening and becoming unworkable before you have had the chance to use it.
Finishing resin is a light weight, two part, epoxy laminating / finishing type resin used when fiber-glassing. It can also be used to seal all engine and fuel tank areas and is absolutely the best for sheeting foam wing panels for aeromodellers. It will bond to itself and does not get brittle with age. But like cyano, you must use the right formulation produced specifically for use with foam. Many finishing resins will just eat up a foam wing. Finishing resin can also be used to seal and prepare all types of wood projects for painting. Finishing resin will penetrate into porous wood, so several applications may be required to fill and level the surface.
Windows in models, whether they be airplane cockpit windows, car or speedboat windscreens can easily be spoiled by using inappropriate adhesives on the clear Perspex canopies and windscreens. There are special canopy glues available for these applications which are just another formulation with the advantage that they dry clear and transparent. So don't go spoiling your creation for want of a little extra investment in the right adhesive.
These days there is an adhesive for every task. Despite the great diversity of modern adhesives you will quickly find the smaller range appropriate to your own craft, hobby or modelling requirement. You will find a favourite manufacturer and quickly develop your own expertise in its use. You only need to put in a little investigation before you begin to get off on the right foot and ensure that your model hangs together for a good long time.
