GRP Exterior Surfaces

USS SHRIKE (MHC 62), a coastal minehunter with GRP hull construction.
U.S. Navy Photo

General Overview

  • Designed for application on Glass Reinforced Plastic (GRP) (fiberglass) exterior surfaces of U.S. Navy vessels.
  • Applicable to the large, very visible gray areas not receiving non-skid.
  • These areas are coated with an anti-corrosive primer then top coated with haze gray paint.
  • Color was chosen for the visual camouflage it provides in the open ocean.

New Technology Areas

Low Solar Absorption (LSA) coatings
  • Used on exterior surfaces and designed to reduce the heat load on ships.
  • Testing shows a 10-20 degree reduction in ambient and surface temperatures.
  • Sailors and equipment benefit by interior compartments staying cooler during warm weather.
  • Already tested and in use.
  • Seeking products with enhanced LSA pigmentation provide increased reflectance and less color change.
Anti-Stain Coatings
  • Designed to reduce running rust on topside shipboard surfaces by using chelating agents to turn the rust into a transparent film.
  • Benefits include: less touch-up painting by ship's force, easy-to-clean surfaces and a better topside appearance.
  • The Navy is seeking coatings containing enhanced, more durable anti-stain properties and easier cleaning properties.
Solvent Free Coatings for Topside Use
  • Currently being used by the U.S. Navy for tank, void and well deck overhead coatings.
  • Environmentally friendly and provide a substantial increase in service life expectancy.
  • Seeking products with similar technology topside areas.

Surface Preparation Requirements

Use one of the following surface preparation methods defined in NAVSEA Standard Item 009-32 Table 2. GRP Fiberglass Surfaces

  • High Pressure Wash-Remove Marine Growth and Loose Paint
  • Light Abrasive Blasting with Black Walnut Shells - Touch up or Removal of Paint System to Sound Primer AND Spot Clean (NSTM Chapter 631)

Approved Coatings and Applicable Coating Specificatons

Use one of the following coating applications defined in NAVSEA Standard Item 009-32 Table 2 GRP Fiberglass Surfaces

For primer, and topcoats, use military specification MIL-DTL-24441/QPL-24441 Type IV, F-150, F-152, F-151 and related documents.

For horizontal surfaces, decks & fittings, vertical surfaces and paint designations and marking use one of the following military specifications and related documents: MIL-PRF-24635/QPL-24635 Deck Gray, No. 26008 LSA Only (FED STD 595), Deck Gray No. 26270 LSA Only (FED STD 595). 

MIL-PRF-24763/QPL-24763 Type II, Class 2 products may also be used for vertical surfaces and paint designations and markings.

See the NAVSEA Approved Coatings Messages for additional approved coatings.

U.S. Navy Guidelines and Instructions

Coating Application Process

Preservation Process Instructions (PPIs) were developed by NAVSEA 05P23 to document the latest requirements and procedures for coating applications. These documents contain information on cleaning, surface preparation, coating application, quality assurance requirements, checkpoints and QA inspection forms. The applicable PPIs for GRP preservation are linked below.

Preservation Processs Instructions

PPI 63101-000 - Core

PPI 63101-005H HIGH DURABILITY for Exterior Topside To be used in conjunction with Core PPI 63101-000 with a Surface Preparation Method of Abrasive Blasting  

Key Application Requirements

Key application requirements to be followed during preservation practices are referenced in a variety of document sources. These parameters should be considered and monitored during all preservation practices to assist in ensuring the longevity and service life expectancy of a coating.

The requirements specified in the job order, ship specifications, 009-32, NSTMs, PPIs and additional repair documents have been tested and have proved the most effective measure to ensure coating service life. Some of the requirements referenced include environmental and quality assurance monitoring such as dehumidification, temperature, surface profile measurements and coating thickness measurements.

For more information on these parameters, see Key Application Requirements.

Repair Requirements

Ship’s Force

Ship's force personnel are primarily responsible for maintaining coating integrity until repair activity maintenance is scheduled. Naval Ships Technical Manuals are the primary source of information for ship's force personnel. The applicable Chapter for surface ship preservation is Naval Ships’ Technical Manual (NSTM) Chapter 631, Revision 3, Preservation of Ships in Service- General.            

Repair Activities

The Standard Specification for Ship Repair and Alteration Committee (SSRAC) is responsible for providing technically and contractually sound standards for the Navy's ship repair and alteration community. The NAVSEA Standard Item applicable to surface ship preservation is Standard Item 009-32, "Cleaning and Painting Requirements." It contains cleanliness, surface preparation, and coating application requirements, along with complete system application instructions for each product (number of coats, coating thickness per coat, etc.) approved for GRP preservation.

All current NAVSEA Standard Items may be found here.

New Construction Ships

New construction ships are painted in accordance with the applicable sections of the specific Ship Specification for that class of ship.