Benefits
Flame-Retardant Protection
3M™ Glass Cloth Tape 398FRP is designed for applications requiring flame-retardant performance and meets specified FAR 25.853(a) and FAR 25.855(d) requirements.
Strong Permanent Adhesion
The acrylic adhesive provides high adhesion and excellent long-aging characteristics, making the tape suitable for permanent sealing applications.
Durable Glass Cloth Backing
The woven glass cloth provides resistance to abrasion, puncture, and mechanical wear, helping protect the underlying surface over long periods.
Excellent Conformability
The backing can conform to uneven, curved, and textured surfaces, which is particularly useful when sealing aircraft insulation and panels.
Easy Application
The blue polyethylene skip-slit liner helps facilitate tape application. The printed liner also provides visual identification for applications where aerospace specifications are important.
High-Temperature Capability
398FRP provides long-term temperature resistance from approximately -29°C to 121°C (-20°F to 250°F).
Technical Specifications
| Property | 3M™ Glass Cloth Tape 398FRP |
|---|---|
| Product Type | Flame-Retardant Glass Cloth Tape |
| Backing | Woven Glass Cloth |
| Adhesive | Acrylic |
| Color | White |
| Liner | HD Polyethylene Film |
| Liner Color | Blue |
| Liner Type | Printed Skip-Slit Liner |
| Backing Thickness | 0.13 mm / 5 mil |
| Total Tape Thickness | 0.18 mm / 7 mil |
| Weight | 231 g/m² |
| 180° Peel Adhesion | 4.2 N/cm / 38 oz/in |
| Tensile Strength | 227.7 N/cm / 130 lb/in |
| Elongation at Break | 7% |
| Long-Term Temperature Resistance | 121°C / 250°F |
| Minimum Long-Term Temperature Resistance | -29°C / -20°F |
These are typical values rather than product specifications and should be verified against the latest 3M technical documentation for the specific configuration.
3M currently lists a 2 in × 36 yd, 7 mil configuration of 398FRP, with other configurations potentially varying by market.
Aerospace Specifications & Compliance
For aerospace applications, 3M™ Glass Cloth Tape 398FRP offers several important compliance characteristics.
According to 3M, the product:
- Meets FAR 25.853(a) flame-retardancy requirements
- Meets FAR 25.855(d) flame-retardancy requirements
- Meets the requirements of and can be qualified to Boeing BMS 5-146 Type I, Class I, Grade A
- Is EU compliant with the referenced restrictions on penta-BDE and octa-BDE flame retardants
- Uses a formulation that does not contain antimony
For aircraft “fly-away” applications, 3M notes that products sold for aerospace use are intended to be supplied under an applicable OEM specification or FAA PMA.
Applications
1. Aircraft Cargo Bay Panel Sealing
398FRP is primarily designed for permanent sealing of aircraft cargo bay panels, where adhesion, flame retardancy, and mechanical durability are required.
2. Thermal Insulation Panel Sealing
It is suitable for sealing thermal insulation panels where high adhesion and flame-retardant performance are required.
3. Acoustic Insulation
The tape can be used to seal and protect acoustic insulation assemblies in aerospace applications.
4. Aircraft Duct Sealing
Its conformable glass cloth construction allows it to follow curved and irregular duct surfaces.
5. Aircraft Window Applications
398FR/398FRP documentation identifies aircraft window sealing among potential applications.
6. Wire Harness and Cable Protection
The abrasion-resistant glass cloth backing can provide mechanical protection for selected wire harnesses, cables, and hoses.
7. Aircraft Seat Repair
The flame-retardant and durable construction makes the tape suitable for selected aircraft seat repair applications.
8. Marine & Industrial Applications
The tape can also be considered for selected marine, insulation, sealing, bundling, reinforcement, and industrial applications where its specifications are appropriate.
Compatible Materials
3M™ Glass Cloth Tape 398FRP can be considered for use on suitable:
- Aluminum
- Stainless steel
- Steel
- Aircraft panels
- Fiberglass
- Thermal insulation
- Acoustic insulation
- Industrial fabrics
- Composite materials
- Wire and cable assemblies
- Hoses
- Duct surfaces
- Curved and textured surfaces
Surface preparation is important for achieving reliable adhesion. Actual substrate compatibility should be evaluated before production use.
Industries
Aerospace
Aircraft interiors, cargo compartments, insulation systems, ducts, panels, and aircraft maintenance.
Aviation MRO
Repair and maintenance applications requiring flame-retardant and durable glass cloth tape.
Marine
Selected insulation, sealing, and protection applications.
Electrical & Electronics
Wire harnessing, cable protection, and insulation-related applications.
Automotive
Selected applications requiring high-temperature, abrasion-resistant, or flame-retardant tape.
HVAC
Duct and insulation sealing applications.
Industrial Manufacturing
Bundling, reinforcement, insulation, sealing, and surface protection.
Why Choose 3M™ Glass Cloth Tape 398FRP?
3M™ Glass Cloth Tape 398FRP combines:
Flame Retardancy + Acrylic Adhesion + Glass Cloth Strength + Abrasion Resistance + Easy Application
This combination makes it particularly valuable where ordinary cloth tape cannot meet the application’s flame-retardancy or durability requirements.
Key Advantages
- Aerospace-oriented flame-retardant performance
- Strong acrylic adhesive
- High tensile-strength glass cloth backing
- Excellent abrasion resistance
- Good puncture resistance
- High conformability
- Long-aging adhesive performance
- Printed skip-slit liner
- Antimony-free formulation
- Suitable for permanent sealing
- Suitable for thermal and acoustic insulation applications
3M™ 398FR vs. 398FRP
The two products are closely related.
| Feature | 398FR | 398FRP |
|---|---|---|
| Glass Cloth Backing | ✓ | ✓ |
| Acrylic Adhesive | ✓ | ✓ |
| Flame Retardant | ✓ | ✓ |
| White Color | ✓ | ✓ |
| Total Thickness | 0.18 mm | 0.18 mm |
| High Conformability | ✓ | ✓ |
| Blue Skip-Slit Liner | Available | ✓ |
| Printed Liner | — | ✓ |
| Aerospace Identification | Standard | Enhanced through printed liner |
The P in 398FRP is particularly relevant to its printed liner configuration. 3M specifically describes 398FRP as being mounted on a printed skip-slit liner for ease of application, while 398FR is available on a skip-slit liner.
Installation Guide
Step 1: Clean the Surface
Remove dust, grease, oil, moisture, release agents, and other contaminants.
Step 2: Measure the Required Length
Cut the tape to the required length while keeping the liner intact.
Step 3: Position the Tape
Align the tape with the sealing area.
Step 4: Remove the Liner
Use the skip-slit structure to remove the liner progressively during application.
Step 5: Apply the Tape
Apply the tape smoothly without excessive stretching. Allow the glass cloth backing to conform naturally to curved or irregular surfaces.
Step 6: Apply Pressure
Apply firm, even pressure over the entire bonding area to maximize adhesive contact.
Step 7: Inspect
Check for:
- Air pockets
- Wrinkles
- Lifted edges
- Contamination
- Incomplete contact
- Insufficient overlap
For aerospace applications, follow the applicable aircraft/OEM maintenance documentation and qualification requirements.
Storage
For best performance:
- Store in the original packaging.
- Keep in a clean, dry environment.
- Recommended storage temperature: 16–27°C (60–80°F).
- Recommended relative humidity: 40–60%.
- Protect from direct sunlight.
- Avoid excessive heat and moisture.
- Keep away from chemicals and contaminants.
Always follow the latest 3M storage recommendations for the specific product configuration.
FAQ
What is 3M™ Glass Cloth Tape 398FRP?
3M™ Glass Cloth Tape 398FRP is a flame-retardant glass cloth tape with acrylic adhesive, primarily designed for aerospace sealing and insulation applications.
What is 398FRP used for?
Typical applications include aircraft cargo bay panel sealing, thermal and acoustic insulation sealing, aircraft duct sealing, window applications, wire/cable protection, and selected MRO applications.
Is 3M™ 398FRP flame retardant?
Yes. 3M states that 398FRP meets the specified requirements of FAR 25.853(a) and FAR 25.855(d).
What adhesive does 3M™ 398FRP use?
It uses a pressure-sensitive acrylic adhesive designed to provide high adhesion and long-aging performance.
What is the temperature range of 3M™ 398FRP?
The published long-term temperature range is approximately -29°C to 121°C (-20°F to 250°F).
Is 398FRP suitable for aircraft insulation?
Yes. 3M specifically recommends it for thermal and acoustic insulation panel sealing where high adhesion and flame retardancy are needed.
What is the difference between 398FR and 398FRP?
The principal distinction is the printed skip-slit liner on 398FRP, which provides easier application and visual identification. The underlying tape construction is based on the same flame-retardant glass cloth/acrylic adhesive technology.
Is 398FRP suitable for curved surfaces?
Yes. Its glass cloth backing is highly conformable and designed to bond over difficult textures and uneven or curved surfaces.
Is 3M™ 398FRP waterproof?
It should not be marketed simply as a waterproof tape. Its primary purpose is aerospace sealing and flame-retardant protection. Waterproof performance depends on the substrate, joint design, overlap, environmental exposure, and application conditions.
Can 3M™ 398FRP be die-cut?
Yes, glass cloth tapes can be converted into custom shapes using suitable industrial die-cutting processes. Tooling and process parameters should be evaluated for the required geometry and production volume.
Can 3M™ 398FRP be slit into narrow widths?
Yes. The product is available in different width configurations, and suitable tape converters can provide slit formats when compatible master-roll specifications are available.
Downloads
Available upon request:
- 3M Glass Cloth Tape 398FRP Technical Data Sheet (TDS)
- Safety Data Sheet (SDS)
- Adhesive Tape Selection Guide
- Product Brochure
- Die-Cutting Capability Guide
Please contact our sales team if you require the latest technical documentation.
