Back-To-Basics: Adhesion Failure

Details Posted on 05 February 2019 | Share: | Print

Sometimes going back-to-basics can make the difference between a quality repair and a failed repair. When it comes to spraying refinish materials, there are some common mistakes that are easily avoidable and can have a huge effect on the adhesion of the refinish materials and the outcome of the repair.

What is adhesion failure? It is the peeling, delaminating, or chipping of the refinish coatings. Adhesion failure can be peeling between two coats, but most commonly, the basecoat and clearcoat, or the new finish and the original finish. You can find failures in small areas, or even in large areas. Adhesion failure can typically be seen once the masking material is removed and can even peel away with the masking material.

Adhesion failure can be caused by:

• Improper film build.
• If the film thickness is excessive and the flash time between two coats was too short, this may cause failure.
• Contaminants on the surface
• Make sure refinishing area is clean and free of contaminants like dust and oils. Overspray and improper sanding of the original surface can also cause adhesion failure.
• Masking material
• If the masking material is directly in contact with the area being refinished, it can cause the refinish material to lift. Masking tape can leave an adhesive residue on the panel being refinished and will not allow the refinish material to adhere. If the masking material is removed when the paint is too dry, it may remove some refinish materials with it.
• Incompatible materials
• The use of materials such as primers and sealers that are not compatible with the basecoat, there may be an adhesion failure between those layers. Check with the product maker to ensure the materials you are using will be compatible with each other. Stay within one paint maker system, and do not mix products.
• Improperly mixed or expired materials
• Refinish materials that are not properly or thoroughly mixed can cause failure between layers. Check the label on the products being used to make sure they are not expired. Expired materials may keep the material from adhering and curing, causing the refinish material to peel away.

These are just a few examples on how adhesion failure can occur, and how to avoid it. Always follow the paint maker instructions and standard operating procedures to ensure a complete, safe, and quality repair.

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