Workshop Basics: Choose Your Glues
Choosing the right glue for the right job can be a bit confusing. This table shows you how to select the right glue, based on the materials that need to be bonded.
NOTE: This table is just a guideline, always remember to read the packaging, and obey any safety instructions provided with your products. Some of the solvents used in adhesives are toxic and flammable. Always assume the worst case scenario could happen, and always work in a well ventilated area.
Different Types of Glue
Here is a short list of the most popular glues.
Acrobutylstyrene cement is an emulsion containing ABS and a solvent (usually MEK). ABS cement will also glue acrylic and polystyrene.
Acrylic cement uses dichloromethane, trichloroethane, or butanone to weld acrylic surfaces together. It is available as liquid or gel, and in liquid form can be applied with a natural brush.
Balsa cement will glue most porous substances like cardboard or balsa wood. Balsa Cement usually contains some sort of synthetic resin which bonds the surfaces together using as an adhesive rather than a weld.
Cyanoacrylate glue sets in seconds and are extremely strong. CNA requires a dry, grease free surface in order to bond properly, but will adhere to most materials. It is worth remembering that superglue was originally created to glue human skin, and should be treated with the caution it deserves.
Epoxy is very strong resin glue, and it is both waterproof and solvent-proof. It is inflexible, and should only be used to glue rigid materials, although it does not shrink as it sets. Depending on the type of epoxy used, the setting time for the resin can range from 2 minutes to a full day. Most epoxy resins require a catalysing agent, but some types of epoxy putty begin to dry when they are exposed to air.
Polyester and Polyvinyl Resin
Polyvinyl and polyester resins are synthetic resins that need to be mixed with a catalysing agent (hardener) before use. When mixed in the correct proportions, the resins will form a strong, waterproof bond in about three hours. Synthetic resins can be used as a casting agent, and combined with other materials to form resin composites.
Polyvinyl Acetate glue is a general-purpose adhesive, and is sometimes called craft glue or wood glue. It is water-soluble while it is liquid, but impervious to water once it has set. PVA can be mixed with water and powder paint to make waterproof, flexible paints, and will also work as a binding agent for Plaster of Paris. Mixed in a 50% solution with water it can be painted onto textiles to make them waterproof, and when mixed with fine wood shavings it can be used as a wood filler. PVA takes 24 hours to dry, and gluing surfaces must be clamped together until the drying time for the glue has expired.
Rubber based glue is a general purpose, waterproof adhesive that is suitable for bonding both rigid and flexible materials, usually taking 24 hours to reach full strength. Latex is a good example of a water based rubber glue, and usually much thicker than a solvent based rubber glue. You can increase the thickness of latex using an additive called a thixotropic.