There are two main ways of joining objects together. One is through physical methods such as tying, nailing, sewing and fastening with Velcro and rivets. The other is through chemical means using an adhesive. Natural adhesives such as Japanese lacquer and glue have been used from ancient times. Other materials such as casein from clotted milk, starch found in grain, mud and plaster have also been used as adhesives for a long time. With advances in the field of chemistry and the development of new ingredients, there has been an increase in the number of multi-purpose, multi-function adhesive products in recent years.
The features and suitability of an adhesive should be checked prior to use. For example, with vinyl acetate wood glue, moisture contained in the glue is absorbed by the wood, and this is how the ingredients solidify to bring about adhesion. Therefore, it cannot be used on metal objects which do not absorb moisture. Cyanoacrylate instant adhesives are used on metal, synthetic rubber, hard plastic, etc. but are vulnerable to impact. Epoxy adhesives which harden as a result of a chemical reaction induced by mixing two liquids together may be used widely, even on glass and concrete, but are not suitable for soft vinyl and rubber. There are also hot-melt adhesives which are applied by heating and melting a glue substance which solidifies and binds objects together when it cools. When choosing adhesives, thought must be given to the material to be bonded and the conditions and locations in which it will be used (For example, how much physical force it will have to bear and the indoor and outdoor usage environment).
The methods and precautions for use will differ for each type of adhesive but there are some common points to be remembered. First of all, dirt on the surface to be bonded must be removed before the adhesive is applied. If there is grease or moisture on the surface, the adhesive may not be able to exert its full force. It is also a good idea to try the product out on an extra piece of material first before using it on the actual piece. Care is needed during use because if a tool or a hand with adhesive on it comes into contact with a piece of furniture, this could cause the paint on the furniture to come off. When using any type of adhesive, be sure to follow the instructions and precautions indicated on the product. Various types of adhesives can be purchased at home centers and art supply stores.
- Examples of methods for joining objects togetherTying