OVERCOAT PEN Chemtronics CW3300G CONDUCTIVE GREEN CIRCUIT WORKS

The CircuitWorks CW3300G Overcoat Pen by Chemtronics is a professional-grade conformal coating dispenser designed for precise protection and insulation of printed circuit boards (PCBs), components, and delicate electronics. The pen dispenses a tough, modified acrylic polymer coating that dries to a hard, durable green finish at room temperature, closely matching the appearance of standard PCB solder mask — making it perfect for professional-looking repairs, prototyping, and production work.

The pen is engineered for single-handed, precision application: gently squeezing the pen body releases just the right amount of coating from the fiber tip, allowing accurate placement on fine traces, repair sites, exposed copper, or component leads without flooding the surrounding area. The coating cures tack-free in under 5 minutes at room temperature and reaches a typical thickness of 2–3 mil (50–75 µm).

It is the ideal companion product to the CircuitWorks Conductive Pen — after repairing a broken trace with conductive silver, use the Overcoat Pen to seal, insulate, and protect the repair from oxidation, shorting, and mechanical damage. It also serves as an excellent solder mask repair solution for scratched or damaged PCBs, and provides robust protection against moisture, abrasion, dust, fungus, salt spray, and high-voltage arcing.

The cured coating has a high dielectric strength of >500 volts/mil, excellent moisture resistance, flexibility, and a wide service temperature range of -55°C to +125°C. The product is RoHS compliant and meets the rigorous requirements of MIL-I-46058C and IPC-CC-830A — the industry-standard specifications for electronic conformal coatings.

Important notes:

• Apply as the final step in board processing — the coating decomposes above 132°C (270°F), so do not apply before any further soldering operations.
• For best adhesion, clean the board first with an appropriate flux/contamination remover (e.g., Chemtronics Electro-Wash).
• If post-soldering coating is needed, use Chemtronics CircuitWorks Epoxy Overcoat (CW2500) instead.

Specifications

Product Details

• Manufacturer: Chemtronics (ITW)
• Brand Line: CircuitWorks®
• Part Number: CW3300G
• Product Type: Conformal Overcoat Pen
• Color: Green (matches typical PCB solder mask)
• Net Weight: 4.9 g (0.16 oz)
• Dispenser: Squeeze-pen with fiber tip
• Shelf Life: 2 years

Material Composition

• Coating Material: Polymeric (modified acrylic) conformal coating
• VOC Content: 630 g/L

Cured Properties

• Service Temperature Range: −55°C to +125°C (−67°F to +255°F)
• Tack-Free Time: < 5 minutes
• Full Cure Time: ~10 minutes at room temperature
• Typical Coating Thickness: 2–3 mil (50–75 µm)
• Resistivity: >10¹² Ω·cm @ 50 VDC
• Dielectric Breakdown: >500 volts/mil DC
• Dielectric Constant: 3 – 4
• Dissipation Factor: <0.001 @ 1 kHz
• Thermal Shock Resistance: Pass, 10 cycles (−55°C to +155°C)
• Flexibility: Excellent
• Moisture Resistance: Excellent
• Adhesion: Good to excellent

Standards & Compliance

• MIL-I-46058C compliant
• IPC-CC-830A compliant
• RoHS compliant

Application Limits

• Maximum temperature before decomposition: 132°C (270°F) — apply after all soldering is complete

Applications

• PCB trace insulation and protection
• Solder mask repair on prototype and production boards
• Sealing CircuitWorks Conductive Pen repairs
• Protection of components against environmental damage
• High-voltage circuit insulation (prevents arcing)
• Moisture and fungus protection for electronics in humid environments
• Marine and outdoor electronics protection
• Automotive electronics repair and protection
• Industrial control board maintenance
• Prototype board finishing with a professional appearance
• Field repair kits for service technicians
• Educational and hobby electronics projects
• Aerospace and military electronics (per MIL-I-46058C)