DOWSIL™ 3-1953 Conformal Coating

Harmonization Code : 3910.00.00.90 | Silicones in Primary Forms; Others

DOWSIL™ 3-1953 Conformal Coating

Main features

  • One-part, solventless silicone conformal coating
  • UV indicator for inspection and quality assurance
  • Soft, stress-relieving elastomer after cure

Product Description

DOWSIL™ 3-1953 Conformal Coating is a solventless, elastomeric silicone coating designed to protect printed circuit boards and electronic assemblies in lighting, industrial, and automotive applications. It provides reliable protection against moisture, corrosion, thermal cycling, and environmental contaminants while maintaining electrical insulation performance. The coating cures at room temperature through exposure to atmospheric moisture and forms a flexible elastomer that helps protect electronic assemblies under demanding operating conditions.

Key features

  • Solventless silicone system - 100% silicone elastomer with no solvent carrier.
  • Low-to-medium viscosity - Supports spray, dip, and selective coating application methods.
  • Room-temperature cure - Cures through solvent evaporation followed by silicone crosslinking to form a durable elastomer.
  • Flexible elastomer after cure - Helps reduce mechanical stress on solder joints and electronic components.
  • Excellent environmental protection - Helps protect against moisture, corrosion, dust, and industrial contaminants.
  • Electrical insulation performance - Provides reliable dielectric protection for electronic assemblies.
  • UV indicator - Enables visual inspection and verification of coating coverage under UV light.

Applications

DOWSIL™ 3-1953 Conformal Coating is suitable for electronic assemblies where solvent-based silicone coating, uniform coverage of printed circuit boards, and UV-assisted coating inspection are part of the application review.

  • Rigid and flexible circuit boards: suitable for protective coating of printed circuit boards and PCB system applications.
  • PCB assembly protection: supports environmental protection, corrosion resistance, and dielectric protection requirements.
  • Sensitive electronics and fine-pitch designs: suitable for tightly spaced geometries where low-viscosity flow is required to achieve uniform coverage.

Related resources

Product Family

DS-31953

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TDS, SDS & Technical Documents
  • 11-3046-01-dowsil-3-1953-conformal-coating
    English (Technical Data Sheet (TDS))
  • DOWSIL™ 3-1953 Conformal Coating-Safety Data Sheet-EN
    English (Safety Data Sheet (SDS))

Technical Specifications

General Properties
Color Color
Translucent
Specific Gravity Specific Gravity
0.98
Physical Properties
Viscosity Viscosity
350 mPa.s
Mechanical Properties
Elongation Elongation
60 %
Electrical Properties
Dielectric Strength Dielectric Strength
17 kV/mm
Volume Resistivity Volume Resistivity
5.5e+15 Ohms⋅cm
Thermal Properties
UL 94 Rating UL 94 Rating
V-0

Additional Information

moisture cure conformal coating

DOWSIL™ 3-1953 RTV Coating

DOWSIL™ 3-1953 Conformal Coating is a solvent-based silicone conformal coating designed to protect printed circuit boards and electronic assemblies from moisture, corrosion, thermal cycling, and environmental contaminants. The coating features a low viscosity that enables uniform application across complex geometries and cures at room temperature primarily through solvent evaporation followed by silicone cure.

one part 350 cP viscosity MIL A-46058 IPC-CC-830

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

Product Package
DOWSIL™ 3-1953 RTV Coating
RTV Coatings

Silicone Conformal Coating for Electronic Protection

DOWSIL™ 3-1953 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™ 3-1953 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

  • Room-temperature cure - Cures through solvent evaporation followed by silicone crosslinking.
  • Solvent-free formulation - 100% solids silicone system with no solvents or by-products.
  • Low viscosity coating - Supports spray, dip, and selective coating application methods
  • 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.

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
One or Two Part One  
Color Translucent  
Viscosity 350
350
0.4
cP
mPa-sec
Pa-sec
Specific Gravity (Cured) 0.98  
NVC (Non Volatile Content) 99.4 %
Tack-Free Time at 25ºC 8 minutes
Tack-Free Time at 60ºC/15% RH 0.5 minutes
Tensile Strength 80
0.5
5
psi
MPa
kg/cm2
Elongation 60 %
Durometer Shore A 34  
Dielectric Strength (JIS K 6249) 3 Volts/mil
kV/mm
Dielectric Strength  425
17
ohm*cm
Volume Resistivity (JIS K 6249) 5.5 E15  
Dissipation Factor at 100 Hz 0.0007  
Dissipation Factor at 100 kHz < 0.0002 -
Hardening Transition by DSC -56.2
-49
F
°C-
UL Flammability Classification 94 V-0 -
Mil Specification Mil I-46058C Amend 7 -
Agency Listing IPC-CC-830A with
Amendment 1, UL 746E
-
Cyclotetrasiloxane (D4) content < 0.1 %
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™ 3-1953 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™ 3-1953 RTV Coating

What is DOWSIL™ 3-1953 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™ 3-1953 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™ 3-1953 RTV Coating can be evaluated against your application-specific qualification plan.

 

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