Panduit CMP-300-1 Copper Joint Compound 8oz
Overview
The Panduit CMP-300-1 is an 8-ounce electrical joint compound formulated for copper-to-copper (CO-CO) and copper-to-steel (CO-ST) terminations. Applied at connection points before fastening lugs, compression connectors, or bus bar joints, it fills microscopic surface voids, displaces moisture, and inhibits oxidation — the primary cause of resistance creep at high-current terminations over time. If you're commissioning switchgear, panel terminations, or grounding conductors and want those joints to hold their contact resistance years down the line, this is a standard prep step that costs very little relative to a callback.
The CMP-300-1 (often searched as CMP 300 1) ships in a single 8oz unit, sized appropriately for a typical service panel or switchboard termination job without leaving large quantities of opened compound to degrade on the shelf.
Key Features
- High Flash Point (>260 °C): The compound won't ignite during normal installation or energized termination work — relevant when working near live bus or in warm switchgear enclosures where ambient temperatures can be elevated.
- CO-CO and CO-ST Coverage: One product handles both copper-to-copper and copper-to-steel joint types, so installers don't need to stock separate compounds for mixed-metal bus applications — common in commercial panelboards and grounding systems.
- Oxidation Inhibition: Copper oxidizes at exposed surfaces; the compound seals the interface from air and moisture ingress, maintaining low contact resistance at the joint over the service life of the installation.
- 8oz Single-Pack Format: Right-sized for small to mid-scale panel work. Avoids the waste and shelf-life concerns of larger bulk containers on jobs where only a moderate number of terminations need treatment.
Integration & Compatibility
The CMP-300-1 is designed for use with Panduit copper compression lugs, connectors, and bus bar termination hardware, and is broadly applicable wherever CO-CO or CO-ST joints are made in commercial electrical and low-voltage infrastructure installations. Consult the applicable connector installation instructions to confirm whether joint compound is specified for the termination type.
Frequently Asked Questions
Q: What joint types is the CMP-300-1 designed for?
A: The CMP-300-1 is formulated for copper-to-copper (CO-CO) and copper-to-steel (CO-ST) terminations.
Q: What is the flash point of the CMP-300-1 compound?
A: The flash point is greater than 260°C, making it safe for use in typical electrical installation environments.
Q: How much compound is included per package?
A: Each CMP-300-1 package contains one 8-ounce (8oz) container.
Q: Can the CMP-300-1 be used on aluminum conductors?
A: The product is specified for CO-CO and CO-ST (copper-to-copper and copper-to-steel) applications. For aluminum or aluminum-to-copper joints, consult Panduit's product line for the appropriate compound designation.
The Panduit CMP-300-1 is a straightforward electrical consumable, but skipping joint compound on high-current copper terminations is the kind of shortcut that shows up years later as a hot connection or nuisance trip. The >260°C flash point means you're not introducing a fire hazard into switchgear work — that's not a trivial spec when you're torquing lugs in a warm 480V panel.
Technical Highlights:
- Flash Point >260°C: Eliminates ignition risk during installation near energized bus or in enclosed switchgear where ambient heat accumulates — a practical safety margin for field use.
- Dual-substrate formulation (CO-CO / CO-ST): Covers both copper-to-copper and copper-to-steel joints with a single product, which simplifies the consumables kit for installers working mixed-metal termination points in commercial panelboards and grounding arrays.
- 8oz single-pack: The per-pack format is well-matched to service panel or switchboard jobs; avoids opening a large container that degrades once exposed to air over multiple jobs.
Deployment Considerations:
- Apply a thin, even coat to the contact surfaces of both connector and conductor before compression or torque — excess compound squeezed out of the joint doesn't add protection and can attract debris.
- The CMP-300-1 is rated for CO-CO and CO-ST only — do not substitute for aluminum-rated compound (AL-CU joints require a different formulation with more aggressive abrasive content to break through aluminum oxide).
This compound is the right call for commercial electrical infrastructure work — switchgear terminations, grounding conductors, and bus bar joints — where long service intervals make oxidation resistance at the connection point genuinely worth the two-minute prep step.
