Standard
Structural Damage and Deep Dent Repair
A layered repair system for deep dents, holes, cracks and weld areas: fibre-reinforced fillers provide strength and a finishing filler a smooth surface.
- ZN-530
- ZN-120
- ZN-125
- ZN-130
- ZN-210
- ZN-310
Sector solution
Composite, GRP and Fibreglass Parts
Fibre-reinforced filler and primer systems for cracks and breaks in bus and truck cab parts, caravan panels and GRP enclosures.
Sector overview
Glass-reinforced polyester (GRP) and other composite materials are widely used in bus front and rear panels, truck cab spoilers, caravan bodies and industrial enclosures because they are lightweight and easy to mould. However, these parts behave differently from metal: on impact they crack rather than dent, their layers can separate and hairline cracks can form in the gelcoat on the surface. When repairs are made only at the surface, a common problem is that the cracks soon reappear.
Zenova's composite solutions are based on a layered filling approach using Fibreglass Filler and Micro Fibreglass Filler. These polyester-based fillers form a strong repair layer that is compatible with GRP surfaces. On parts with deep delamination, however, a laminate repair with glass fibre and resin must be carried out first. For thermoplastic trims and decorative parts, the Plastic Part Repair System, built on 1K Plastic Primer and Joker Multi-Purpose Primer, is recommended.
Challenges and solutions
- 01
Recurring cracks
Cracks that are only filled at the surface soon reappear due to vibration and thermal expansion. Opening the crack into a V-groove and bridging it with Fibreglass Filler makes the repair area more durable.
- 02
Mould release and adhesion problems
Mould release residues on new GRP parts can prevent filler and primer from adhering. Cleaning with Surface Cleaning Thinner, followed by sanding, creates a sound base for adhesion.
- 03
Porosity and pinholes
Pores exposed on sanded gelcoat and filler surfaces show through after painting. Soft Finishing Filler and 4+1 Acrylic Primer Filler seal these defects, creating a closed, smooth surface for the basecoat.
- 04
Identifying the material correctly
Thermoset GRP parts and thermoplastic trims are not repaired in the same way. The Structural Damage and Deep Dent Repair system defines the correct product sequence for GRP, while the Plastic Part Repair System does so for thermoplastics such as PP and ABS.
Recommended systems
Application systems for Composite, GRP and Fibreglass Parts
- Standard
Plastic Part Repair System
Strong adhesion and a fast workflow on plastic parts such as bumpers, spoilers and mirror covers, with 1K Plastic Primer and wet-on-wet Joker Multi-Purpose Primer.
- ZN-530
- ZN-240
- ZN-250
- ZN-320
Featured products
The most widely used products in this sector
- 2KFillerZN-120
Fibreglass Filler
High-strength, glass-fibre-reinforced 2K structural filler. Ideal for deep dents, tears, small holes and repairs to GRP/fibreglass parts.
View product - 2KFillerZN-125
Micro Fibreglass Filler
2K filler reinforced with micro glass fibres, combining the strength of a fibreglass filler with a smooth, pore-free surface and much easier sanding.
View product - 2KFillerZN-130
Soft Finishing Filler
Ultra-flexible, creamy 2K finishing filler for large surfaces and thin fills. Sands very easily without clogging the paper, leaving a flawless base for primer.
View product 
2KPrimerZN-2104+1 Acrylic Primer Filler
High-build 2K acrylic primer filler: covers filled areas, does not sag, sands easily and creates a smooth, isolating base for the topcoat.
View product- 1KPrimerZN-240
1K Plastic Primer
Single-component adhesion-promoting primer that forms a strong bond on PP, PP/EPDM and ABS plastics. For bumpers, mirror covers and exterior trim parts.
View product - 2KPrimerZN-250
Joker Multi-Purpose Primer
Hybrid 2K primer for use wet-on-wet or as a sandable primer filler. Adheres to aluminium, galvanised steel, factory coatings and existing paintwork.
View product
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