UNDERSTANDING HOW A PRIMER WORKS
It is a fact that most lining failures occur due to poor surface preparation and a lack of understanding of the relationship between the substrate, the primer and the top lining.
A primers role is to form a mechanical bond with the substrate and a chemical / mechanical bond with the Liner. This is the reason that substrate preparation is so important because we are relying on a mechanical bond between the primer and the substrate. The success of this bond is determined to a large degree by the cleanliness of the substrate at the time the primer is applied.
To enhance the ability of the primer to "grab"hold of the substrate the surface is "roughen" by sand blasting or acid etching. This has the effect of increasing the surface area of the substrate giving the primer more area to bond with.
Obviously if the substrate is contaminated with dust, oil or residue, then this acts as a barrier between the primer and the substrate reducing the effectiveness of the primer.
Contrary to common belief too much primer is worse than not enough. When we create a "profile"on the substrate we are trying to increase the amount of surface area for our primer and top coat to gain adhesion to. If we apply a primer too thickly we only succeed in "filling" up the substrate profile and reducing the amount of surface area that the Liner can bond to.
Primers within themselves do not have any real mechanical strength and therefore if we apply too much primer and create a "layer" of primer between the substrate and the top coat we can experience "primer sheer" which simply means that the primer sheers within itself allowing the bottom half of the primer layer to remain on the substrate and the top half of the primer layer to peel away with the Liner.
The primer's second role is to form a bond with the Liner enhancing the adhesion between the primer and the Liner. Even in applications where the excellent natural adhesion of Rhino Linings products may be satisfactory we take the view that priming is a cheap form of insurance and the use of a primer ensures the quality and integrity of the Rhino Linings system.
Rhino Linings spray applied protective lining systems are "Aromatic" systems meaning they will discolour under UV light. The mechanical characteristics of the lining are not adversely effected by the UV light only the pigmentation.
In applications where colour stability is important like commercial flooring the Rhino Linings product must be "top coated" with a Rhino Linings Aliphatic Top Coat.
Aliphatic (colour fast) top coats provide a fade free finish for the colour sensitive applications of Rhino Linings products.
Rhino Linings top coats are available in virtually any colour and are applied using a roller, paint brush or spray gun (providing they are sprayed in a class 3 approved spray booth as the top coats are flammable).
Rhino Linings Top Coats will provide a diverse range of colour options however they will result in the surface becoming slightly more slippery than standard Rhino Linings products. The Top Coats can be used for safety markings, colour features, and walkway borders.
When a Rhino Linings Top Coat is used on any pedestrian access application it is recommended that a slip resistant aggregate is used in conjunction with the top coat.