SEM 40793 Copperweld Primer 16 oz Gold for MIG and STRSW Welding

Built for the job.

Replaces Previous Part Numbers
Supersedes: SEM.40783.CN. Same formula, updated SKU.

Copperweld™ is a zinc based and copper enriched weld through primer that provides superior corrosion protection between welded substrates while minimizing heat affected zones and welding spatter.

Copperweld™ 40793 Primer is a 16 oz gold-colored epoxy primer designed for professional auto body and collision repair applications. It provides a high-build, corrosion-resistant base coat on bare metal, OEM panels, or previously primed surfaces, delivering reliable adhesion before topcoat application.

Each can covers approximately 15 sq-ft, allowing efficient coverage with a single coat as specified for the product. The formulation is compatible with a range of substrates including untreated steel and existing primer layers, ensuring consistent film formation across typical shop workflows. With a VOC content of 545 g/L, it meets regulatory requirements while delivering the performance expected from an SEM-approved system.

Due to its acute toxicity, flammability, and skin corrosivity, use requires full personal protective equipment: eye protection, chemical-resistant gloves, protective clothing, and a respirator. Operate in a well-ventilated area and follow the H-statements (H222, H280, H315, H319, H336, H351, H373) for safe handling.

Why Pros Choose SEM SEM

• OEM recommended
• Zinc based formula for superior corrosion protection
• Copper enriched for improved conductivity while welding
• Minimizes the heat affected zone while welding
• Low weld spatter formula
• Smooth spraying and easy covering

How to Use

For MIG and STRSW welding

Compatibility

Compatible substrates: Copper.

Specifications

VOC

545 g/l

Shelf Life

Store in a cool, dry place with adequate ventilation away

Compatible Substrates

bare metal, oem, primer

Number of Coats

40793

Coverage

15 sq-ft per can

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 Copperweld™ 40793 Primer be applied to?

It is compatible with bare metal, OEM finishes, and existing primers.

How much area does one 16 oz can cover?

The product provides approximately 15 sq-ft of coverage per can when applied at the recommended film thickness.

What personal protective equipment is required when handling this primer?

Use eye protection, chemical-resistant gloves, protective clothing, and a respirator as specified in the SDS.

Are there any special safety considerations for Copperweld™ 40793 Primer?

The primer has a flash point of -103 °C and is classified with multiple GHS hazards, including acute toxicity, skin corrosion, eye damage, flammability, and carcinogenicity. Follow all H-statements (H222, H280, H315, H319, H336, H351, H373) on the label.

Documents & Safety

• Safety Data Sheet (SDS)
• copperweld_40786_specification_sheet.pdf
• 40793%20Copperweld%20Weld%20Thru%20PrimerUSA.pdf

Signal Word: Danger. Wear chemical-resistant gloves, safety goggles or face shield, protective clothing (coveralls), and a suitable respirator when handling this primer. The product is extremely flammable with a flash point of -103 °C, can cause severe skin burns and eye damage, is toxic if inhaled or swallowed, and poses long-term health risks including carcinogenicity and reproductive effects. It is also 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 [email protected].