Benefits
Flame-Retardant Performance
3M™ Glass Cloth Tape 398FR is designed for applications where flame-retardant performance is required. It meets specified FAR 25.853(a) and FAR 25.855(d) requirements.
High Adhesion
The acrylic adhesive provides strong adhesion to a variety of substrates and is designed for permanent applications requiring reliable long-term bonding.
Excellent Abrasion Resistance
The glass cloth backing provides a durable protective layer that resists abrasion during handling and service.
Puncture Resistance
The reinforced glass cloth construction provides good resistance to puncturing, helping protect insulation, wires, cables, and other components.
High Conformability
398FR can conform to uneven, curved, and textured surfaces, making it easier to install over aircraft panels, insulation, ducts, and other irregular substrates.
Long-Term Durability
The acrylic adhesive and glass cloth backing are designed for long-aging performance in demanding industrial and aerospace environments.
Temperature Resistance
3M lists an operating temperature range of approximately -29°C to 121°C (-20°F to 250°F).
Technical Specifications
| Property | 3M™ Glass Cloth Tape 398FR |
|---|---|
| Product Type | Flame-Retardant Glass Cloth Tape |
| Backing | Woven Glass Cloth |
| Adhesive | Acrylic |
| Color | White |
| Liner | Blue Polyethylene Film |
| Total Thickness | Approx. 0.18 mm / 7 mil |
| Backing Thickness | Approx. 0.13 mm / 5 mil |
| Elongation at Break | Approx. 9% |
| Peel Adhesion to Stainless Steel | Approx. 15 N/25 mm |
| Tensile Strength | Approx. 220 N/25 mm |
| Dielectric Strength | Approx. 3.8 kV |
| Operating Temperature | Approx. -29°C to 121°C |
| Standard Roll Length | Approx. 33 m / 36 yd |
| Backing Type | Glass Cloth |
| Adhesive Technology | Pressure-Sensitive Acrylic |
The values above are typical values from 3M technical documentation and should not be treated as product specifications. Always verify the latest TDS for the exact product configuration.
Industry Specifications & Compliance
One of the key advantages of 3M™ Glass Cloth Tape 398FR is its suitability for aerospace applications.
The product is reported by 3M to:
- Meet FAR 25.853(a) flame-retardancy requirements
- Meet FAR 25.855(d) flame-retardancy requirements
- Meet requirements of and can be qualified to Boeing BMS 5-146 Type I, Class I, Grade A
- Comply with the referenced EU restrictions concerning certain flame retardants
- Be suitable for applications requiring flame-retardant sealing and protection
For aerospace production, qualification and OEM approval requirements should always be confirmed for the specific application.
Applications
1. Aircraft Cargo Bay Panel Sealing
3M primarily designed 398FR for sealing aircraft cargo bay panels, where high adhesion, flame retardancy, and abrasion-resistant backing are important.
2. Thermal Insulation Panel Sealing
The tape is suitable for sealing thermal insulation panels where both adhesion and flame-retardant performance are required.
3. Acoustic Insulation
398FR can be used to seal and secure acoustic insulation panels in aerospace applications.
4. Aircraft Window Sealing
3M lists aircraft window sealing as an application example for 398FR.
5. Aircraft Duct Sealing
The conformable glass cloth backing allows the tape to be applied to curved and irregular duct surfaces.
6. Aircraft Seat Repair
398FR can be used for selected aircraft seat repair applications where its flame-retardant and durable construction is appropriate.
7. Wire Harness & Cable Protection
The abrasion-resistant glass cloth backing can help protect wire harnesses, electrical cables, and hoses from temperature extremes and mechanical abrasion.
8. Marine Applications
398FR is also identified by 3M for selected marine applications.
9. General Industrial Sealing
Beyond aerospace, the tape can be used for industrial insulating, bundling, splicing, holding, reinforcement, and sealing applications.
Compatible Materials
3M™ Glass Cloth Tape 398FR can be considered for use with suitable:
- Aluminum
- Stainless steel
- Steel
- Aircraft panels
- Fiberglass
- Thermal insulation materials
- Acoustic insulation materials
- Electrical cables
- Wire harnesses
- Hoses
- Industrial fabrics
- Composite materials
- Textured and curved surfaces
Surface preparation is important. Always evaluate adhesion on the actual substrate before production use.
Industries
Aerospace
Aircraft cargo compartments, insulation, ducts, window sealing, seat repair, and wire/cable protection.
Aviation MRO
Suitable for selected aircraft maintenance and repair applications where the product specification is applicable.
Marine
Used for selected marine insulation, sealing, and protection applications.
Electrical & Electronics
Suitable for selected cable, wire harness, insulation, and protective applications.
Automotive
Can be considered for selected high-temperature and flame-retardant component protection applications.
HVAC
Useful for sealing insulation and selected duct-related applications.
Industrial Manufacturing
Suitable for bundling, splicing, holding, reinforcement, insulation, and sealing.
Why Choose 3M™ Glass Cloth Tape 398FR?
3M™ Glass Cloth Tape 398FR combines four important performance characteristics:
Flame Retardancy + High Adhesion + Glass Cloth Strength + Abrasion Resistance
This makes it particularly valuable for applications where ordinary cloth tape or general-purpose adhesive tape is insufficient.
Key Advantages
- Aerospace-oriented flame-retardant performance
- Strong acrylic adhesive
- Durable glass cloth backing
- High tensile strength
- Excellent abrasion resistance
- Good puncture resistance
- High conformability
- Long-term aging performance
- Good solvent resistance
- Suitable for demanding sealing applications
For aerospace insulation and sealing, 398FR is more application-specific than ordinary glass cloth tape, particularly when flame-retardant requirements are part of the specification.
Installation Guide
Step 1: Prepare the Surface
Remove dust, oil, grease, moisture, release agents, and other contaminants.
For difficult substrates, an appropriate surface preparation method may be required.
Step 2: Measure and Cut
Select the appropriate tape width and cut the required length.
Step 3: Position the Tape
Align the tape carefully with the sealing or protection area.
Step 4: Apply the Tape
Apply the tape smoothly without excessive stretching. On curved or irregular surfaces, gradually conform the glass cloth backing to the substrate.
Step 5: Apply Pressure
Apply firm, uniform pressure across the tape to maximize adhesive contact.
Step 6: Inspect the Bond
Check for:
- Wrinkles
- Air pockets
- Lifted edges
- Incomplete contact
- Contamination
- Insufficient overlap
Step 7: Validate the Application
For aerospace or other regulated applications, verify that the selected tape configuration meets the applicable engineering and regulatory requirements before production use.
Storage
For optimum performance, 3M recommends storing 398FR:
- In the original packaging
- At 16–27°C (60–80°F)
- At 40–60% relative humidity
- Away from direct sunlight
- In a clean, dry environment
3M recommends using the product within 24 months from the date of manufacture when stored under the specified conditions.
FAQ
What is 3M™ Glass Cloth Tape 398FR?
3M™ Glass Cloth Tape 398FR is a flame-retardant glass cloth tape with acrylic adhesive, developed primarily for aerospace sealing, insulation, protection, and maintenance applications.
Is 3M™ 398FR flame retardant?
Yes. 398FR is designed to meet the specified FAR 25.853(a) and FAR 25.855(d) flame-retardancy requirements.
What is 3M™ 398FR used for?
Typical applications include aircraft cargo bay panel sealing, thermal and acoustic insulation sealing, aircraft window sealing, duct sealing, seat repair, wire harness protection, cable protection, marine applications, and general industrial sealing.
What type of adhesive does 3M 398FR use?
3M™ 398FR uses a pressure-sensitive acrylic adhesive.
What is the temperature range of 3M™ 398FR?
3M lists an operating temperature range of approximately -29°C to 121°C (-20°F to 250°F).
Is 3M™ 398FR suitable for aerospace applications?
Yes. It is specifically designed for aerospace-related applications and meets specified FAR flame-retardancy requirements. It can also be qualified to Boeing BMS 5-146 Type I, Class I, Grade A, subject to applicable qualification requirements.
Is 3M™ 398FR suitable for aircraft insulation?
Yes. Sealing thermal and acoustic insulation panels is one of its recommended applications.
Can 3M™ 398FR be used on curved surfaces?
Yes. Its highly conformable glass cloth backing is designed to bond over difficult textures and uneven or curved surfaces.
Is 3M™ 398FR waterproof?
It should not automatically be described as a waterproof tape. It offers good resistance to environmental conditions and solvents, but whether it provides the required waterproof seal depends on the substrate, joint design, overlap, temperature, and application conditions.
Can 3M™ 398FR be die-cut?
Yes, glass cloth tapes can be converted into custom shapes using appropriate industrial converting processes. For precision die-cutting, tooling and material behavior should be evaluated against the required geometry and production volume.
Can 3M™ 398FR be slit into custom widths?
Yes. The tape is available in multiple widths, and suitable converting suppliers can slit compatible master rolls into narrower widths depending on the product configuration.
What is the difference between 3M 398FR and 398FRP?
398FRP is the printed version of 398FR. The standard 398FR is generally used where a plain white glass cloth tape is required, while 398FRP provides printed identification/marking for applicable applications.
Downloads
Available upon request:
- 3M Glass Cloth Tape 398FR 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.
