Which adhesive is usually supplied in two parts that must be mixed prior to use?

The adhesive that is usually supplied in two parts that must be mixed prior to use is contact cement, commonly referred to as contact adhesive. This type of adhesive requires the user to combine two components, typically a resin and a hardener, to initiate the bonding process. Once mixed, the adhesive can bond surfaces that require strong and durable adhesion, which is often crucial in construction and woodworking applications.

Contact cement is particularly useful for bonding large surfaces and offers strong initial tack, allowing materials to be joined together immediately upon contact. The mixing of the two parts is essential, as it activates the chemical reaction that provides the adhesive strength.

In contrast, wood glue, super glue, and hot glue come ready to use without any need for prior mixing. Wood glue is designed specifically for bonding wood and works effectively with porous surfaces. Super glue (cyanoacrylate) provides a strong bond quickly but does not require any mixing. Hot glue is applied in a molten state and hardens as it cools, making it another adhesive that is ready to use without preparation.