Definition - What does Bond Coat mean?
A bond coat is typically based in polymer and can act as a defense against corrosion and other forms of damage. It is identical to tack coats, however, it is proprietary. It is fabricated to act in the same way as tack coat, but either designed for specific applications or general functions though with more improved properties.
This type of coat is mainly used by industrial contractors for resurfacing, repair jobs and new constructions.
Corrosionpedia explains Bond Coat
The utilization of bond coats depends on specific preference. Most industry organizations suggest the application of bond coat to prevent future damage to a structure as well as to preserve its aesthetic appearance. It is also applied to obtain the maximum bond strength.
In almost all application situations, wet or fresh concrete does not exhibit outstanding bonding to dry concrete. According to various testing, a powerful bond between these two types of concrete can be achieved with the use of bond coats containing a broad variety of epoxies and copolymers as well as:
- Polyvinyl acetate
- Acrylic resins
Such kinds of bond coats are especially recommended in colder temperatures, as these can be more durable to repeated thaw and freeze cycles.
Bond coats can greatly aid in preventing damage by making the bonds existing between layers stronger to guarantee powerful adhesion. It is also very beneficial on repair work, particularly in situations where the concrete involved is worth preserving or still sound in structure.
In its application, one of the most essential things is timing. If new concrete layers are added on top on another layer during the same day the concrete was applied, bond coats may not be necessary. However, a bond coat remains a good option for any period after the first application.
Ideal surface preparation and cleaning is required before any form of bonding activity is performed. In order to see if the bond is adequately strong, all that is needed is to use a hammer and slightly tap the surface of the concrete after 24 hours of bond application. If a hollow echo sound is heard, the bond between layers is strong enough.