DOWSIL™ 3-1944 RTV Coating

Harmonization Code : 3910.00.00.90 | Silicones in Primary Forms; Others

DOWSIL™ 3-1944 RTV Coating

Main features

  • One-part silicone coating, room-temperature curing
  • Low viscosity for complete wetting of complex geometries
  • Durable, flexible protective layer

Product Description

DOWSIL™ 3-1944 RTV Coating is a one-part, no-added-solvent silicone conformal coating designed for protection of printed circuit boards and electronic assemblies. It is formulated to provide high-viscosity, controlled flow application for targeted coating, spot protection, and thin-section encapsulation. The material cures at room temperature through exposure to atmospheric moisture and can be heat-accelerated to support manufacturing efficiency. Once cured, it forms a soft, flexible elastomer that provides electrical insulation, environmental protection, and stress relief for sensitive electronic components and interconnects.

Key features

  • No-added-solvent silicone system - 100% silicone formulation eliminates solvent handling and evaporation concerns.
  • High viscosity (~64,000 cP) - Enables controlled application and prevents excessive flow on vertical or localized areas.
  • Moisture-cure RTV chemistry - Cures at room temperature with optional heat acceleration.
  • Soft elastomer after cure - Provides low-stress protection for sensitive components and solder joints.
  • Spot and localized application control - Suitable for selective coating and targeted protection areas.
  • Electrical insulation performance - Provides reliable dielectric protection for PCB assemblies.
  • UV indicator - Enables inspection and verification of coating coverage under UV light.

Applications

DOWSIL™ 3-1944 RTV Coating is used for conformal coating of printed circuit boards and electronic assemblies where localized protection, controlled application, and higher coating build-up are required.

  • Pin/solder joint coverage: suitable for localized protection of exposed conductive areas such as pins, solder joints, and lead terminations where environmental sealing and electrical insulation are required.
  • Thin-section encapsulation: suitable for encapsulating small electronic features and components where flexible, low-stress silicone protection is required in confined or delicate areas.
  • Spot protection of pins or other devices: suitable for targeted application on connectors, pins, and sensitive components requiring localized environmental protection and moisture resistance.

Related resources

Product Family

DS-31944

Catalog Product

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Packaging
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TDS, SDS & Technical Documents
  • DOWSIL™ 3-1944 RTV Coating-Safety Data Sheet-EN
    English (Safety Data Sheet (SDS))
  • 11-1867-01-dowsil-3-1944-rtv-coating
    English (Technical Data Sheet (TDS))

Technical Specifications

Physical Properties
Viscosity Viscosity
63775 mPa.s
Young's modulus Young's modulus
1.54 MPa
General Properties
Specific Gravity Specific Gravity
1.03
Mechanical Properties
Elongation Elongation
145 %
Electrical Properties
Dielectric Strength Dielectric Strength
21 kV/mm
Volume Resistivity Volume Resistivity
1.6e+15 Ohms⋅cm
Thermal Properties
UL 94 Rating UL 94 Rating
V-0

Additional Information

moisture cure conformal coating

DOWSIL™ 3-1944 RTV Coating

DOWSIL™ 3-1944 RTV Coating is a one-part, solvent-free silicone conformal coating designed to protect printed circuit boards and electronic assemblies from moisture, corrosion, thermal cycling, and environmental contaminants. The coating features a high viscosity of approximately 64,000 cP, cures at room temperature through exposure to atmospheric moisture, and can be heat-accelerated to support manufacturing efficiency.

one part 64,000 cP mixed viscosity MIL A-46058 IPC-CC-830

Review the technical data sheet and SDS before handling, processing, or qualifying the material.


DOWSIL™ 3-1944 RTV Coating
RTV Coatings

Silicone Conformal Coating for Electronic Protection

DOWSIL™ 3-1944 RTV Coating cures upon exposure to atmospheric moisture, eliminating the need for solvent evaporation during processing. Its room-temperature cure can be accelerated with mild heat to support faster production cycles. The coating's high-viscosity, self-leveling formulation is suitable for a range of application methods and provides consistent coverage of electronic assemblies.

As a cured elastomer, DOWSIL™ 3-1944 RTV Coating delivers excellent flexibility and low modulus properties, helping to minimize mechanical stress on sensitive components, solder joints, and interconnections during thermal cycling and environmental exposure.

Key features

  • Moisture-cure RTV system - Cures at room temperature upon exposure to atmospheric moisture with optional heat acceleration.
  • Solvent-free formulation - 100% solids silicone system with no solvents or by-products.
  • High viscosity coating - ~64,000 cP viscosity enables controlled application and good coverage of PCB surfaces.
  • Flexible elastomer after cure - Shore A 36 material reduces mechanical stress on sensitive components and solder joints.
  • UV indicator - Facilitates inspection and verification of coating coverage under UV light.
  • Reliable environmental protection - Provides resistance to moisture, corrosion, and contaminants in harsh environments.

Processing summary

Mix ratio: one part
Working time at 25°C: 20 minutes, listed as pot life in the technical data sheet.
Cure: 24 hours at 25°C.
Application method: brush, flow coat, or syringe/needle.
Product resources

Product Documents and Dow Coating Resources

Review the technical data sheet for typical product properties, the safety data sheet for handling and storage requirements, and the Dow conformal coatings selection guide for broader context on the coating family.

Conformal Coatings Selection Guide

Use the selection guide to compare DOWSIL™ conformal coating options by viscosity, cure profile, hardness, and agency listing context.

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What this selection guide covers

The Dow conformal coatings selection guide explains how silicone coatings are positioned by viscosity, cure profile, hardness, stress relief, abrasion resistance, UV inspection, and agency listing context. It also includes a solventless coating section for applications where reducing solvent-handling complexity is a key selection driver, along with comparison tables for solventless RTV, solventless heat-cure, and solvent-based RTV conformal coatings.

Typical properties

Performance Properties

Cure basis and test conditions are per technical data sheet unless otherwise stated.

Property Typical value Unit
Extrusion Rate 1816 g/min 
Viscosity  63775
63775
63.8 
cP
mPa-sec
Pa-sec 
Specific Gravity 1.03   
Tack-free Time at 25°C  14 minutes 
Durometer Shore A 36  
Tack-free Time at 60°C/15% RH  0.5 minutes
Tensile Strength  325
2.2
22 
psi
MPa
kg/cm2
Elongation  145 %
Youngs Modulus 223
1.54
15.4 
psi
MPa
kg/cm2
Unprimed Adhesion - 180 Degree  5 ppi 
Peel Strength  3 N/cm 
Dielectric Strength  525
21
volts/mil
kV/mm 
Volume Resistivity  1.6 E15 ohm*cm 
Shelf Life at 25°C  12 months
UL Flammability Classification 94 V-0 -
Mil Specification  Mil I-46058C Amend 7  -
Agency Listing IPC-CC-830B, UL 746E   
Storage and handling, per technical data sheet
Shelf life is indicated by the Use Before date on the product label. Refer to the product label for storage temperature requirements. Containers should be kept tightly closed and headspace minimized. Partially filled containers should be purged with dry air or other gases such as nitrogen. Exposure to moisture could reduce adhesion and cause bubbles to form.
Applications

Where DOWSIL™ 3-1944 fits

Potting material for power supplies
Pin and Solder Joint Coverage
May be considered for conformal coating applications requiring coverage of pins, solder joints, and other exposed conductive elements where environmental protection, electrical insulation, and long-term reliability are part of the material selection review.
Encapsulant for sensors and connectors
Thin Section Encapsulation
May be considered for thin-section encapsulation of electronic components where a flexible, low-modulus silicone material is desired to help protect against moisture, contaminants, and stresses associated with thermal cycling.
Potting material for industrial controls and transformers
Spot Protection of Pins or Other Devices
May be considered for spot protection of pins, connectors, leads, and other exposed electronic devices where localized environmental protection, electrical insulation, and moisture resistance are part of the material selection review.
Technical guidance

Tips and troubleshooting

Issue Recommended action
Air entrapment or voids
  • Minimize air entrapment during pouring or dispensing.
  • Use vacuum dispensing when practical, especially for assemblies with small voids.
  • Evacuate the unit after dispensing when vacuum dispensing cannot be used.
Adhesion below target
  • Clean and dry substrates before conformal coating application.
  • With RTV cure coatings, dhesion lags behind cure and may take up to 72 hours to build.
    On certain difficult, low-surface-energy surfaces, adhesion may be improved by priming or by special surface treatment such as chemical or plasma etching. 


Curing
  • Time to cure will depend on method of application, film thickness, temperature, and humidity.
  • Cure time for full cure are indications of time needed to develop full physical properties, such as durometer, tensile strength or adhesion.
  • These times, including full cure time, can be significantly improved by introducing mild heat of 60°C or less. 
Moisture exposure during storage
  • Keep containers tightly closed.
  • Minimize headspace after opening.
  • Purge partially filled containers with dry air or nitrogen where appropriate.
Repair or rework requirement
  • Cut and remove unwanted cured elastomer from the repair area.
  • Remove adhered elastomer by mechanical scraping or rubbing as needed.
  • Roughen exposed cured surfaces, rinse with suitable solvent, and dry before recoating.
FAQ

Frequently asked questions about DOWSIL™ 3-1944 RTV Coating

What is DOWSIL™ 3-1944 RTV Conformal Coating used for?

It is used as a protective conformal coating for rigid and flexible circuit boards and PCB system applications, particularly where flexibility, abrasion resistance, dielectric protection, and room temperature cure are part of the application review.

How does this coating cure?

DOWSIL™ 3-1944 RTV Coating can be applied through brush, flow coat, or needle/dispense. It cures by atmospheric moisture at room temperature. Mild heat can be used to accelerate processing after sufficient solvent flash-off.

Which application methods are supported?

DOWSIL™ 3-1944 RTV Coating can be applied through brush, flow coat, or needle/dispense. Process fit should be confirmed against the target wet-film thickness, board layout, masking approach, and keep-out areas.

What does the UV indicator confirm?

The UV indicator supports inspection of coating presence. It should not be treated as proof of final dry-film thickness, full cure, adhesion, absence of defects, or long-term electrical reliability.

Next steps

Review DOWSIL™ 3-1944 for your conformal coating application

Share your substrate materials, application method, coating thickness requirements, cure constraints, electrical performance requirements, environmental exposure conditions, and any industry compliance needs so DOWSIL™ 3-1944 RTV Coating can be evaluated against your application-specific qualification plan.

 

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