HUMISEAL 1B51NSLU/521EU
Harmonization Code : 3403.19 | Lubricating Preparations (With 70% or More Petroleum Oils) For Automotive and Other Uses

Main features
- 521EU Thinner Compatibility
- Low-Permeability Flexible Film
- Room-Temperature and Heat Cure
Product Description
HumiSeal 1B51NSLU/521EU Synthetic Rubber Conformal Coating is a fast-drying single-component synthetic rubber conformal coating used with HumiSeal 521EU thinner for printed circuit assembly protection. The 1B51NSLU coating uses a methylcyclohexane solvent system and forms a flexible, UV-fluorescent, repairable film with low moisture-vapor permeability. Compatible thinner options include 903, 905, and 521EU. The recommended coating thickness is 25 to 75 um, with cure completed in 24 hours at room temperature or 30 minutes at 76 deg C. The cured coating is stated for thermal-shock exposure from -65 to 125 deg C.
Key features
- 521EU application-thinner compatibility: The coating is supported with HumiSeal 521EU for application-viscosity adjustment.
- Flexible UV-inspectable film: The final synthetic rubber film is flexible, UV fluorescent, and repairable.
- Room-temperature or accelerated cure: The coating cures in 24 hours at room temperature or 30 minutes at 76 deg C.
Applications
- Conformal coating of printed circuit assemblies
- Moisture and environmental protection of electronic assemblies
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Thermal Properties
Electrical Properties
Additional Information
As-supplied / before-processing properties
Supported base-coating composition, thinner compatibility, and shelf-life data before application.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Product form | Single-component liquid coating | - | 1B51NSLU base coating |
| Base polymer | Synthetic rubber | - | As supplied |
| Solvent system | Methylcyclohexane | - | As supplied |
| Compatible thinners | 903; 905; 521EU | - | Application-viscosity adjustment |
| Shelf life at room temperature | 18 | months | 1B51NSLU base coating |
| Inspection aid | UV fluorescence | - | Optical brightener in the coating |
After-processing / final-state properties
Supported applied-film and cured-coating characteristics for the 1B51NSLU system.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Recommended coating thickness | 25 to 75 | um | Applied conformal coating |
| Recommended cure | 24 h at room temperature or 30 min at 76 deg C | - | Cure schedule |
| Thermal-shock range | -65 to 125 | deg C | stated cured-coating exposure |
| Glass transition temperature | 14 | deg C | Typical cured coating |
| Moisture-vapor behavior | Low permeability | - | Cured synthetic rubber film |
| Flexibility | Flexible | - | Cured film |
| Inspection aid | UV fluorescence | - | Cured film |
| Repairability | Repairable | - | Cured film |





















