3M
3M Ultrapro 8360 1-Part Seam Sealer, White, 10.5 oz Flex-Pack
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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 Ultrapro 08360 is a single-component, paste-type seam sealer designed for automotive panel repair. It provides a flexible, durable seal on bare metal and primer surfaces, making it ideal for filling seams, joints, and gaps before final coating.
The formulation cures to handling strength in approximately 30 minutes at ambient conditions and reaches full cure within the specified temperature range of 20 °F to 180 °F (-28 °C to 82 °C). Its one-part system eliminates mixing errors and ensures consistent flash time across applications.
Use requires standard personal protective equipment: eye protection, chemical-resistant gloves, protective clothing, and a respirator in areas with inadequate ventilation. Follow the SDS for first-aid procedures and handle according to the listed GHS hazard classifications.
Why Pros Choose 3M 1-Part, Economical
- 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 (bare metal or primer) of all contaminants, grease, and loose material; ensure a dry surface.
- Verify that ambient temperature is between 20 °F and 180 °F (-28 °C to 82 °C) before applying.
- Apply the paste directly from the flex-pack using a brush or trowel, covering the seam evenly. One coat is sufficient for most repairs.
- Allow the sealer to cure for at least 30 minutes at the specified temperature range before handling or sanding.
- If additional coats are required, repeat steps 3-4 after the previous coat has fully cured.
Compatibility
Compatible substrates: Bare Metal.
Compatible paint systems: Urethane, Epoxy, Solvent.
Specifications
| Part No. | 8360 |
|---|---|
| Product Line | MMM |
| MFR Model | 08360 |
| 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 |
| Trade Mark | Ultrapro™ |
| Alternate Part Number-1 | 60980034718 |
| UPC | 051131168305 |
| Brand | 3M™ |
| Maximum Sale Quantity | 6 |
| Maximum Sale Day | 7 |
| Applicable Materials | Metal |
| Composition | 20 to 40% Urethane Polymer, 10 to 30% PVC, 10 to 30% Sulfonic Acids, 4 to 10% Xylene, 1 to 5% Titanium Dioxide, 1 to 5% Calcium Oxide, 0.5 to 2% Ethylbenzene, '0.5 to 1.5% Hydrotreated Light Petroleum Distillates, <0.2% P,P'-Methylenebis(Phenyl Isocyanate) |
| Application Time | 5 to 10 min |
| Paintable (Y/N) | Yes |
| Specific Gravity | 1.17 |
| Base Type | Urethane |
| Component | 1K |
| Odor/Scent | Solvent |
| Color | White |
| Container Size (mL) | 310 |
| Flash Point | 137 deg C |
| Container Size (oz) | 10.5 |
| Container Type | Flex-Pack |
| Form | Paste |
| Temperature Rating (deg F) | >200 deg C Autoignition, -30 to 200 |
| Type | 1-Part, Economical |
| Curing Time | 30 min |
- 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 this seam sealer to?
It is compatible with bare metal and primer surfaces.
How long does the seam sealer take to cure?
The product cures in approximately 30 minutes.
What personal protective equipment is required when using this product?
Wear eye protection, chemical-resistant gloves, protective clothing, and a respirator as recommended by the SDS.
At what temperature range can I apply the seam sealer?
Application is approved from 20 °F to 180 °F (-28 °C to 82 °C).
Documents & Safety
DANGER: This seam sealer contains hazardous chemicals that can cause serious health effects including cancer, reproductive harm, eye damage, and respiratory irritation. Required PPE: safety glasses, chemical-resistant gloves, protective clothing, and respirator. May cause skin and eye irritation on contact. Contains materials that are harmful if inhaled or swallowed. 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.
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 30 min. 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 10.5 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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