Physical basics
Elementary gluing know -how
Basically, gluing joins parts together by means of a layer of adhesive. Evaporation or a chemical reaction hardens the adhesive film and thus holds the materials together.
The durability of the joint depends on two factors:
The Adhesion
A high degree of adhesion is achieved when there is close contact between the surfaces of the parts and the adhesive. That is only possible when there is nothing else between the adhesive and the parts.
That means the surfaces to be stuck together must be clean and free of grease and dust.
Adhesion can be improved further by roughening the surface of the material with emery paper, since that cleans the part of any foreign bodies and at the same time increases the surface area.
Cohesion (the inner holding power of the adhesive)
Cohesion is the power of the molecules of the adhesive to hold together.
The greater the cohesion, the firmer the adhesive.
When sticking things together, cohesion can be used to best advantage if the adhesive is not spread too thickly
