Built for the job.
Dual-Mix™ Heavy bodied seam sealer is a high viscosity, two-component epoxy for use on interior or exterior seams, joints and voids.
Dual‑Mix™ 40377 Heavy‑Bodied 2‑Component Seam Sealer is a high‑strength, low‑VOC liquid formulated for sealing seams, joints, and repair areas on automotive bodies. Delivered in a 7 oz cartridge, it provides a robust, flexible seal that can be sanded and painted after cure.
The sealer offers a 10‑minute work time and a 15‑minute sandable window at 70 °F (21 °C), allowing ample handling before finishing. Full cure is achieved in 1 hour under the same conditions, enabling rapid return to shop flow. It bonds to bare metal, OEM finishes, and primer‑coated substrates, delivering a durable, seamless fill with zero VOC emissions.
Handling requires standard personal protective equipment: eye protection, chemical‑resistant gloves, protective clothing, and a respirator in confined spaces. The product has a flash point of 257 °C and carries acute toxicity, eye damage, and respiratory hazards; ensure adequate ventilation and follow H‑statements H302, H315, H317, H319, and H335.
Why Pros Choose SEM Heavy Bodied 2-Component
- Dual-Mix™ forever warranty
- OEM recommended
- Direct to metal
- Paintable immediately with most solvent-based coatings
- Correct color minimizes post-inspection liability
- Non-sag formula holds tooling marks
- Fast cure increases production
- Remains flexible without shrinking or cracking
- Sprayable for additional versatility
- Ideal for use with new ORBiT™ to duplicate OE ripple bead
How to Use
For use on bare metal, OEM finish, epoxy primer and DTM urethane primer
- Clean the substrate (bare metal, OEM finish, or primer) to remove dust, oil, and loose material.
- Mix the two components of Dual‑Mix™ 40377 according to the label directions; the mixed material has a work time of 10 minutes at 70 °F (21 °C).
- Apply the seam sealer with a brush or spatula, forming a continuous bead over the seam. One coat is sufficient.
- Allow the material to become sandable after approximately 15 minutes, then sand to the desired finish.
- Let the seam sealer fully cure for 1 hour at 70 °F (21 °C) before proceeding with any subsequent coating or paint work.
Compatibility
Compatible paint systems: Epoxy, Solvent.
Specifications
| Part No. | 40377 |
|---|---|
| Product Line | SEM |
| MFR Model | 40377 |
| Standard/Approvals | GHS07 | GHS08 | OSHA HCS Hazard | OEM Approved | California PROP65 Warning: Cancer and Reproductive Harm |
| Application | For use on bare metal, OEM finish, epoxy primer and DTM urethane primer |
| Manufacturer | SEM |
| UPC | 646786403774 |
| Brand | Dual-Mix™ |
| Maximum Sale Quantity | 6 |
| Maximum Sale Day | 7 |
| Applicable Materials | Bare metal, Primed Surfaces |
| Composition | 30 to 40% Bisphenola(chloro)oxirane Polymer, 5 to 7% Fumed Silica, 5 to 7% Epoxy Resin, 1.5 to 5% Modified Diglycidal Ether |
| Application Time | 10 min at 70 deg F |
| Paintable (Y/N) | Yes |
| Sprayable (Y/N) | Yes |
| Odor/Scent | Characteristic |
| Color | Black |
| Setting Time | 15 min at 70 deg F |
| Flash Point | 257 deg C |
| Container Size (oz) | 7 |
| Container Type | Cartridge |
| Form | Liquid |
| Temperature Rating (deg F) | 70 |
| Type | Heavy Bodied 2-Component |
| Curing Time | 1 hr at 70 deg F |
- Cure Time
- 1 hr @ 70 °F (21 °C)
- Work Time
- 10 min @ 70 °F (21 °C)
- Sandable Time
- 15 min
- VOC
- Zero
- Compatible Substrates
- Bare metal, OEM, primer
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™ 40377 Heavy Bodied Seam Sealer be applied to?
It is compatible with bare metal, OEM finishes, and primer‑coated surfaces.
How long does the sealer take to cure?
Full cure is achieved in 1 hour at 70 °F (21 °C).
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 and paint over the seam sealer, and if so, when?
The material becomes sandable after approximately 15 minutes and can be painted once fully cured (1 hour at 70 °F).
Documents & Safety
- Safety Data Sheet (SDS)
- dualmix_39337_catalog.pdf
- dualmix_40377_specification_sheet.pdf
- 40377%20Heavy%20Bodied%20Black%20Seam%20SealerUSA.pdf
Warning: This product is toxic if inhaled, can cause severe skin corrosion and eye damage, may affect internal organs and reproductive health, and is hazardous to aquatic life. Wear safety goggles or face shield, chemical‑resistant gloves, protective clothing (coveralls), and a suitable respirator when handling. 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].








