SEM
SEM Dual-Mix 39777 High-Build Self Leveling Seam Sealer 7 oz Gray Cartridge
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Hazardous material · Liquid
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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.
Dual-Mix™ High-build self leveling seam sealer is a two-component, controlled flow epoxy ideal for use on roof seams, drip rails and trunk seams.
Dual-Mix™ 39777 High-Build Self Leveling 2-Component Seam Sealer is a gray liquid designed for seamless repair of structural seams and panel joints in automotive body work. Formulated as a two-component system, it provides a high-build fill that levels itself to create a smooth substrate ready for finishing.
Key performance data include a 60-minute work time, sandable after just 15 minutes, and full cure within 48 hours. The formulation is zero-VOC and adheres to a wide range of substrates, including aluminum, bare metal, e-coat, fiberglass, OEM plastics, primer, SMC, and steel, making it suitable for most body shop applications.
Handling requires strict PPE: eye protection, chemical-resistant gloves, protective clothing, and a respirator. The product is classified with acute toxicity, aquatic toxicity, carcinogenicity, and other hazards (H315, H317, H319, H335, H351). Use in a well-ventilated area and follow first-aid procedures as outlined in the SDS.
Why Pros Choose SEM High-Build Self Leveling 2-Component
- Dual-Mix™ forever warranty
- OEM recommended
- Direct to metal on non-flexing roof skins
- Paintable in 15 min
- Will not shrink, harden or crack
- Permanently flexible
How to Use
For use on bare metal, OEM finish, epoxy primer and DTM urethane primer
- Clean and degrease the substrate (aluminum, steel, fiberglass, plastic, etc.) to remove contaminants.
- Mix the two components according to the manufacturer's instructions; use the mixed material within its 60-minute work time.
- Apply a uniform coat with a brush or roller. The product self-levels to fill seams and gaps.
- Allow the sealant to become sandable (approximately 15 minutes) before light sanding if needed.
- Let the repaired area cure for 48 hours before applying subsequent coats or finish systems.
Compatibility
Compatible paint systems: Epoxy.
Specifications
| Part No. | 39777 |
|---|---|
| Product Line | SEM |
| MFR Model | 39777 |
| Standard/Approvals | GHS07 | GHS08 | OSHA HCS Hazard | OEM Approved | California PROP65 Warning: Cancer and Reproductive Harm |
| Includes | High Build Self Leveling |
| Application | For use on bare metal, OEM finish, epoxy primer and DTM urethane primer |
| Manufacturer | SEM |
| UPC | 646786397776 |
| Brand | Dual-Mix™ |
| Maximum Sale Quantity | 6 |
| Maximum Sale Day | 7 |
| Applicable Materials | Bare Metal, Epoxy Primer, DTM Urethane Primer |
| Composition | 30 to 40% Bisphenola(chloro)oxirane Polymer, >=7 to <10% Cellulose, 1.5 to 5% Epoxy Resin, 1.5 to 5% Modified Diglycidal Ether, 1.5 to <5% 2,4,6-tris(dimethylaminomethyl)phenol, 1 to 1.5% 7 Fumed Silica , >=0.1 to <1% Castor Oil Glycidal Ether, >=0.1 to <1% 1,3-bis(2,3 -epoxypropoxy)-2,2-dimethylpropane , >=0.1-<1% [3-(2,3-epoxypropoxy)propyl]trimethoxysilane |
| Application Time | 10 min at 70 deg F |
| Paintable (Y/N) | Yes |
| Odor/Scent | Characteristic |
| Color | Gray |
| Setting Time | 15 min at 70 deg F |
| Flash Point | 249 deg C |
| Container Size (oz) | 7 |
| Container Type | Cartridge |
| Form | Liquid |
| Temperature Rating (deg F) | 70 |
| Type | High-Build Self Leveling 2-Component |
| Curing Time | 1 hr at 70 deg F |
- Cure Time
- 48 hr
- Sandable
- 15 min
- Work Time
- 60 min
- VOC
- Zero VOC
- Substrates
- Aluminum, bare metal, e-coat, fiberglass, OEM, plastic, primer, SMC, steel
About SEM
SEM Products specializes in paint adhesion systems, flexible coatings, and plastic repair — the go-to choice for interior and trim refinishing.
Frequently Asked Questions
What substrates can Dual-Mix™ 39777 be applied to?
It is compatible with aluminum, bare metal, e-coat, fiberglass, OEM plastic, primer, SMC and steel.
How long does the seam sealer take to cure?
The full cure time is 48 hours at typical shop conditions.
What personal protective equipment is required when handling this product?
Wear eye protection, chemical-resistant gloves, protective clothing and a respirator as indicated on the SDS.
Can I sand or paint over the sealant after application?
The material becomes sandable after about 15 minutes and remains workable for up to 60 minutes, allowing sanding and subsequent painting once cured.
Documents & Safety
Signal word: Danger.
PPE required: safety glasses or goggles, chemical-resistant gloves, protective clothing (coveralls), and a respirator suitable for organic vapors.
This product is toxic if inhaled, can cause severe skin burns and eye injury, may affect internal organs and reproductive health, is classified as a carcinogen, and is hazardous to aquatic life. Always refer to the full SDS before use.
PPE required: safety glasses or goggles, chemical-resistant gloves, protective clothing (coveralls), and a respirator suitable for organic vapors.
This product is toxic if inhaled, can cause severe skin burns and eye injury, may affect internal organs and reproductive health, is classified as a carcinogen, and is hazardous to aquatic life. 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 SEM is 1 hr at 70 deg F. 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 SEM in a 7 container. Check the autofxmart catalog for other sizes and bulk pricing.
Most in-stock orders for SEM 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 SEM 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 SEM is 39777. Use this number when cross-referencing against TDS, SDS, or legacy supplier catalogs.
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