Built for the job.
3M™ SMC/Fiberglass Repair Adhesive – 3 is a two-part urethane used to bond rigid plastics, such as Sheet Molded Compound (SMC), Fiber Reinforced Polyester (FRP), Fiberglass, Metton® and primed metal.
3M Automix Fiberglass Repair Adhesive (400 mL cartridge, green) is a two-component polyester resin formulated for rapid structural repairs on fiberglass, FRP, ABS, OEM plastics and other compatible substrates. The low-viscosity liquid provides excellent sprayability, allowing precise fill of cracks, dents and delaminations before sanding.
Key performance metrics include a 3 minute work time with flash (sandable) time at 30 minutes and full cure in another 30 minutes, enabling multiple coats-up to ten per application-without excessive downtime. The adhesive bonds directly to polyester primers, SMC, and untreated composites, delivering strong, durable repairs that can be sanded and finished to match surrounding panels.
Due to its acute toxicity, flammability and oxidizing properties, the product requires full PPE: eye protection, chemical-resistant gloves, protective clothing and a respirator in well-ventilated areas. Follow standard first-aid procedures for inhalation, skin or eye contact as outlined in the SDS.
Why Pros Choose 3M MMA
- Two-part urethane or two-part epoxy adhesives effectively bond rigid plastic
- Commonly used to bond backup strips to SMC and FRP (traditional fiberglass)
- Frequently used for backside reinforcement repair on a variety of plastic components
- Adhesive offers excellent sag resistance
- Automatic mixing
- Excellent sag resistance
- Excellent for bonding headlamp buckets
- Achieves maximum work strength fast
- Excellent absorption into fiberglass mat or cloth
- Low viscosity
Application Guide
- Clean and degrease the substrate (ABS, fiberglass, FRP, OEM plastic, polyester, primer, SMC) to remove contaminants.
- Apply the 3M Automix Fiberglass Repair Adhesive with a spray gun or suitable applicator. Use up to 10 thin coats as needed for fill.
- Maintain continuous application within the 3-minute work time window.
- Allow each coat to set for approximately 30 minutes before sanding or applying subsequent coats.
- After the final coat, let the repair cure for a total of 30 minutes before handling or finishing.
Compatibility
Compatible substrates: Fiberglass, Plastic, SMC.
Compatible paint systems: Urethane, Epoxy, Polyester.
Specifications
| Part No. | 8271 |
|---|---|
| Product Line | MMA |
| MFR Model | 08271 |
| Standard/Approvals | OSHA 29 CFR 1910.1200 |
| Manufacturer | 3M Products |
| Trade Mark | Automix™ |
| Alternate Part Number-1 | 60455050264 |
| UPC | 051135082713 |
| Brand | 3M™ |
| Maximum Sale Quantity | 6 |
| Maximum Sale Day | 7 |
| Composition | 30 to 60% Methylene Phenylene Isocyanate, 30 to 60% Urethane Prepolymer, 10 to 30% Diisocyanatodiphenylmethane Polymer, 7 to 13% Talc, 7 to 13% Aluminum Silicate, 1 to 5% Thickening Agent |
| Application Time | 3 min |
| Specific Gravity | 1.288 |
| Odor/Scent | Slight Isocyanate |
| Color | Green |
| Container Size (mL) | 400 |
| Setting Time | 10 min |
| Flash Point | >383 deg F |
| Container Type | Cartridge |
| Form | Liquid |
| Temperature Rating (deg F) | -40 to 180 |
| Curing Time | 30 min |
- Cure Time
- 30 minutes
- Sandable Time
- 30 minutes
- Work Time
- 3 minutes
- Coverage
- Excellent sprayability
- Substrates
- ABS, fiberglass, FRP, OEM, plastic, polyester, primer, SMC
- Coats
- 10
About 3M
3M is a global leader in abrasives, masking, and body repair products. Trusted by OEM collision centers for high-performance prep and finishing solutions.
Frequently Asked Questions
What substrates can I apply 3M Automix 08271 to?
The adhesive is compatible with ABS, fiberglass, FRP, OEM plastics, polyester, primer-coated surfaces, and SMC composites.
How long do I have to work before the material begins to set?
The work (application) time is 3 minutes. After this period the adhesive starts to cure.
When can I sand the repaired area?
Sandable time is also 30 minutes, matching the cure time. Sand after 30 minutes when the surface has hardened.
What personal protective equipment is required when using this product?
Wear eye protection, chemical-resistant gloves, protective clothing, and a respirator as specified on the SDS.
How does the coverage of this adhesive compare to other fillers?
The formulation provides excellent sprayability, allowing efficient application with minimal waste.
Documents & Safety
- Safety Data Sheet (SDS)
- 3m_08984_catalog.pdf
- 3m_08271_specification_sheet.pdf
DANGER: This fiberglass repair adhesive contains hazardous chemicals that can cause serious health effects including cancer, reproductive harm, and organ damage. It is flammable and toxic if inhaled or absorbed through skin. Required PPE: safety glasses, chemical-resistant gloves, protective clothing, and respirator. Use only in well-ventilated areas away from ignition sources. Can cause severe eye and skin irritation. Always refer to the full SDS before use.
Why Buy from autofxmart
- Authorized distributor — authentic, factory-fresh stock.
- Fast US shipping — most orders ship within 1 business day.
- 30-day returns — buy with confidence.
- Pro-shop pricing — bulk discounts available on request.
- Expert support — questions? Email us at [email protected].
