Grounding "Undercoating"
The HP-UC primer system improves the adhesion of 2K PU paints and clear coats on GFRP, CFRP, metals, and paintable plastics. This solvent-based 1K primer is applied directly before coating and ensures a permanent bond, uniform paint application, and long-term durability – even under thermal and mechanical stress.
Primer & adhesion promoter for composites and plastics
What is the HP-UC primer system and how does it work?
The HP-UC primer system is a solvent-based 1K specialty primer that acts as an adhesion promoter between the substrate and subsequent 2K PU topcoats or clear coats. It is specifically designed for fiber-reinforced composites such as GFRP and CFRP, as well as for metals, thermoplastics, and low surface energy plastics. The primer forms a dense, reactive intermediate layer that ensures a durable bond between part and coating. This is crucial on structured technical surfaces requiring chemical resistance and mechanical durability. The system is fast-drying and easy to apply by brush, roller, or spray.
What are the advantages of HP-UC for coating CFRP, GFRP, and plastics?
Using HP-UC effectively solves typical adhesion problems on plastic-based composites. Especially on carbon fiber and glass fiber components to be coated with a 2K PUR topcoat or clear coat, the primer significantly improves the layer stability. It prevents delamination or moisture penetration and resists chemical influences. On thermoplastics and slightly oily surfaces such as ABS or PA, HP-UC achieves even wetting and strong bonding. In combination with in-mould coatings, textured PU finishes, or 1K clear coats, it is an essential part of a professional coating system for composite materials.
What are the typical applications for HP-UC undercoating?
HP-UC undercoating is ideal for projects requiring durable paint adhesion on technical plastics, GFRP parts, or carbon components. Typical uses include boat building, automotive construction, model making, and the coating of technical housings, sports equipment, or design components subject to high mechanical and thermal loads. Used in combination with 2K PUR topcoats such as HP-PP or HP-PUR, the primer ensures that the coating system remains stable even on difficult substrates. With its ease of application, short flash-off time, and broad material compatibility, HP-UC is a reliable solution for workshops, industrial applications, and professional users.