3M
3M 8307 Seam Sealer Cartridge 6.75 oz Clear, 8 min work, 1 hr cure
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Hazardous material · Liquid
Liquid hazmat ships ground-only via UPS/FedEx with a per-item carrier surcharge applied 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 PROP65 Warning: Cancer and Reproductive Harm
Tap for details → P65Warnings.ca.gov
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Overview
Built for the job.
3M™ self-leveling seam sealer is a two-part epoxy designed for roof ditches (door skin hem flanges) and rear body panels, including tail light areas, wheel well flanges, etc. Our seam sealer offers a work time of approximately 8 min and can be painted in 15 min. Quick curing properties enhance automotive body shop…
3M 08307 Sealer is a clear, liquid sealer supplied in a 6.75 fl-oz cartridge for use over primer coats in automotive refinishing. It provides a uniform barrier that prepares the substrate for subsequent paint layers and helps achieve consistent gloss and adhesion.
The formulation offers an 8-minute work (flash) time followed by a rapid cure of 1 hour, allowing up to 10-13 thin coats per cartridge when applied over primed surfaces. This fast turnaround reduces shop cycle time while delivering the film thickness required for high-quality finishes.
Due to its acute toxicity, aspiration hazard, and classification as a carcinogen, proper personal protective equipment is mandatory: eye protection, chemical-resistant gloves, protective clothing, and a respirator with adequate ventilation must be used during application. Follow all SDS recommendations for safe handling and first-aid procedures.
Why Pros Choose 3M MMA
- Self-leveling epoxy designed for areas requiring a flowable type sealer
- Ready for painting in 15 min
- Transparent in color for a low profile appearance
- Cured sealer matches OEM seams for a professional look
- Formula is made for the automotive aftermarket industry
- A high-performance two component epoxy seam sealer
- Self-leveling formulation designed for roof ditches and horizontal rear body panels, including tail light areas
Application Guide
- Ensure the substrate is properly primed; this sealer is compatible with primer-coated surfaces.
- Shake the 6.75 fl-oz cartridge thoroughly before use to achieve a uniform mixture.
- Apply the clear liquid sealer using the recommended spray equipment. Apply 10-13 coats, maintaining continuous motion within the 8-minute work window.
- Allow the coating to cure for at least 1 hour before handling or applying subsequent layers.
Compatibility
Compatible paint systems: Epoxy.
Specifications
| Part No. | 8307 |
|---|---|
| Product Line | MMA |
| MFR Model | 8307 |
| Standard/Approvals | California PROP65 Warning: Cancer and Reproductive Harm | OSHA 29 CFR 1910.1200 |
| Manufacturer | 3M Products |
| Alternate Part Number-1 | 60980105807 |
| UPC | 051131083073 |
| Brand | 3M™ |
| Maximum Sale Quantity | 6 |
| Maximum Sale Day | 7 |
| Composition | 60 to 100% Mercaptan-Terminated Epoxy Curing Agent, 7 to 13% Tris(2,4,6-Dimethylaminomonomethyl)Phenol, <2% Bis[(Dimethylamino)methyl] Phenol |
| Application Time | 8 min |
| Specific Gravity | 1.17 |
| Odor/Scent | Slight |
| Color | Clear |
| Flash Point | >-200 deg F |
| Container Size (oz) | 6.75 |
| Container Type | Cartridge |
| Form | Liquid |
| Temperature Rating (deg F) | -20 to 180 |
| Curing Time | 1 hr |
- Cure Time
- 1 hour
- Work Time
- 8 minutes
- Shelf Life
- After initial use, leave mix nozzle in place to seal the cartridge.
- Compatible Substrates
- Primer
- Number of Coats
- 10-13
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 this sealer to?
The product is formulated for use on primed surfaces. Apply only over a compatible primer before subsequent coats.
How long does it take to cure?
Full cure is achieved in approximately 1 hour at the recommended application temperature.
What personal protective equipment is required when using this product?
Wear eye protection, chemical-resistant gloves, protective clothing, and a respirator approved for organic vapors.
How much working time do I have after dispensing?
The material remains workable for about 8 minutes (flash/working time) before it begins to set.
Documents & Safety
DANGER: This sealer contains hazardous chemicals that can cause serious health effects including cancer, reproductive harm, and organ damage. Required PPE: safety glasses or goggles, chemical-resistant gloves, protective clothing, and appropriate respirator. Avoid skin and eye contact, inhalation, and ingestion. Material can cause severe eye damage and skin irritation. 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 — 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 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
The curing time for 3M Products MMA is 1 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 MMA in a 6.75 container. Check the autofxmart catalog for other sizes and bulk pricing.
Most in-stock orders for 3M Products MMA 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.
The MPN for 3M Products MMA is 8307. Use this number when cross-referencing against TDS, SDS, or legacy supplier catalogs.
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