3M
3M 8364 Beige 1‑Component Seam Sealer 310 mL Flex‑Pack – 24 hr Cure, Paintable After 30 min
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Hazardous material · Paste
This hazardous material ships ground-only. A handling surcharge may be added at checkout.
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Ground freight only (UPS/FedEx). Cannot ship via Air, USPS, or to PO boxes. APO/FPO addresses excluded.
WARNING: Cancer & Reproductive Harm
California Pro65 Warning: Cancer and Reproductive Harm
Tap for details → P65Warnings.ca.gov
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Overview
Built for the job.
Our 3M™ urethane seam sealer is a high solids seam sealer ideal for sealing automotive and RV seams and joints. It adheres well to bare metal, primed metal and painted surfaces and if desired can be smoothed to a featheredge and/or brushed. Tack-free and paintable after 30 to 45 min, this urethane formula is…
3M 08364 is a single-component, beige paste seam sealer designed for automotive body repair where a flexible, durable seal is required on bare metal or primed surfaces. It cures to full strength in 24 hours, providing a reliable barrier against moisture and corrosion.
The formulation remains workable from 20°F to 180°F (-28°C to 82°C), allowing application in most shop environments without temperature restrictions. Its one-component system eliminates mixing errors, and the paste consistency offers excellent coverage for seam joints and panel gaps.
Due to its hazardous classification-including acute toxicity, aspiration hazard, and carcinogenic potential-use requires gloves, protective clothing, and a respirator in a well-ventilated area. Follow standard first-aid procedures: flush eyes with water for at least 15 minutes, wash skin thoroughly, and seek medical attention if inhaled or ingested.
Why Pros Choose 3M 1-Component
- High quality, single-component formula adheres well to bare metal, primed metal and painted surfaces
- Moisture curing property provides excellent performance in high heat and humidity environments
- Non-shrinking, non-cracking, low/no odor formula remains flexible and offers superior results to solvent-based sealers
- Paintable after 30 to 45 min
- Thick consistency is able to fill large voids
- Can be smoothed to a featheredge or brushed
- Recommended for use with 3M™ single-component cartridge applicator gun PN08990 or 3M™ professional caulking gun PN08993
How to Use
For general-purpose automotive seams, including door skins, rocker panels, rear body panels, trunk seams, floor pans and more
- Clean the substrate thoroughly; ensure the surface is bare metal or primed.
- Verify ambient temperature is between 20 °F and 180 °F (-28 °C to 82 °C) before application.
- Apply the paste directly from the flex-pack to the seam using a suitable filler tool; one coat is typical.
- Allow the sealant to cure for 24 hours at the approved temperature range before sanding, priming, or overcoating.
Compatibility
Compatible substrates: Bare Metal.
Compatible paint systems: Urethane, Epoxy, Solvent.
Specifications
| Part No. | 8364 |
|---|---|
| Product Line | MMM |
| MFR Model | 8364 |
| Standard/Approvals | California Pro65 Warning: Cancer and Reproductive Harm |
| Application | For general-purpose automotive seams, including door skins, rocker panels, rear body panels, trunk seams, floor pans and more |
| Manufacturer | 3M Products |
| Alternate Part Number-1 | 60455030910 |
| UPC | 051135083642 |
| Brand | 3M™ |
| Applicable Materials | Bare Metal, Painted Surfaces, Primed Metal |
| Composition | 15 to 40% Urethane Polymer, 10 to 30% PVC Polymer, 10 to 30% Sulfonic Acids, C10-18-Alkane, pH Esters, 5 to 10% Xylene, 1 to 5% Calcium Oxide, 1 to 5% Ethylbenzene, 1 to 5% Hydrotreated Light Petroleum Distillates, 1 to 5% Titanium Dioxide, 0.1 to 1 P,P'-Methylenebis(Phenyl Isocyanate) |
| Application Time | 10 to 20 min |
| Paintable (Y/N) | Yes |
| Specific Gravity | 1.17 |
| Sprayable (Y/N) | Yes |
| Base Type | Moisture-Curing Urethane |
| Component | 1K |
| Color | Beige |
| Container Size (mL) | 310 |
| Flash Point | 92 deg F |
| Container Type | Flex-Pack |
| Form | Paste |
| Temperature Rating (deg F) | -25 to 180 |
| Type | 1-Component |
| Curing Time | 24 hr |
- Application Temp.
- 20 °F - 180 °F (-28 °C - 82 °C)
- Compatible Substrates
- Bare metal, primer
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 the 3M 08364 Seam Sealer to?
The sealer is compatible with bare metal and primer-coated surfaces.
At what temperature range can I apply this seam sealer?
Application is approved from 20°F to 180°F (-28°C to 82°C).
How long does the seam sealer take to cure?
The product reaches full cure in approximately 24 hours under normal conditions.
What personal protective equipment is required when using this product?
Wear chemical-resistant gloves, protective clothing, and a respirator as specified on the SDS.
Documents & Safety
DANGER: This seam sealer contains hazardous chemicals that can cause serious health effects including cancer, reproductive harm, and organ damage. May cause severe eye and skin irritation. Required PPE: chemical-resistant gloves, protective clothing, and respirator. Avoid breathing vapors and prevent skin/eye contact. Use only in well-ventilated areas. Always refer to the full SDS before use.
Why Buy from autofxmart
- Authorized distributor — authentic, factory-fresh stock.
- Fast US shipping — orders ship within 2 business days, lower 48 only.
- 30-day returns — buy with confidence.
- Pro-shop pricing — bulk discounts available on request.
- Expert support — questions? Email us at support@autofxmart.com.
How to apply
Steps
1Clean both surfaces to bare, dry substrate.
2Load the cartridge and fit the mixing nozzle.
3Apply an even bead (or clamp) where needed.
4Tool or smooth the joint before it skins over.
5Allow to cure fully before stressing or painting.
Specifications
Full data
Frequently asked
Good to know
3M Products MMM is compatible with Bare Metal. Always ensure the surface is properly cleaned, degreased, and sanded before application to achieve the strongest adhesion and a professional finish.
The curing time for 3M Products MMM is 24 hr. Drying and curing times may vary with temperature, humidity, and film thickness — always consult the Technical Data Sheet (TDS) for exact cycle conditions.
This listing ships 3M Products MMM in a 310 container. Check the autofxmart catalog for other sizes and bulk pricing.
Most in-stock orders for 3M Products MMM ship the same or next business day from our US warehouse. Expedited options are available at checkout. Freight-class items may require an additional 1–2 days for carrier pickup.
Yes. autofxmart is an authorized distributor of 3M Products. Every unit is factory-fresh, sealed, and backed by the manufacturer's standard warranty. If you have a concern, contact support@autofxmart.com and we will make it right.
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