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PRC-Desoto P/S 860B-1/6-654 Pro-Seal Quick Repair Fuel Tank Sealant

by PPG Aerospace
Product Description
PS-860B-1-6 PRC-Desoto Pro-Seal Quick Repair Fuel Tank Sealant is a two-part, manganese dioxide cured polysulfide compound designed for fillet sealing of fuel tanks and other aircraft fuselage sealing applications. The uncured material is a low sag, thixotropic paste suitable for application by extrusion gun. It has excellent adhesion to common aircraft substrates when correctly primed with PR-148 Adhesion Promoter.
Material Safety Data Sheets (MSDS): MSDS1, MSDS2
Product Specifications
Surface preparation

Immediately before applying sealant to primed substrates, the surfaces should be cleaned with solvents. Contaminants such as dirt, grease, and/or processing lubricants must be removed prior to sealant application.

A progressive cleaning procedure should be employed using the appropriate solvents and new lint free cloth (reclaimed solvents or tissue paper should not be used). Always pour solvent on the cloth to avoid contaminating the solvent supply. Wash one small area at a time. It is important that the surface is dried with a second clean cloth prior to the solvent evaporating to prevent the redeposition of contaminants on the substrate.

Substrate composition can vary greatly. This can affect sealant adhesion. It is recommended that adhesion characteristics to a specific substrate be determined prior to application on production parts or assemblies.

After the surface has been cleaned, apply PR-148 Adhesion Promoter with a clean brush or a gauze pad. Care must be taken to obtain a uniform thin coat. At standard temperature, allow the adhesion promoter to dry 30 minutes.

It is not recommended to apply adhesion promoter below 45F (7C). The sealant must be applied within 8 hours of the application of the adhesion promoter. If this time is exceeded, the surface should be re-cleaned and the adhesion promoter reapplied. Do not use adhesion promoter if it contains particles or precipitate.

For a more thorough discussion of proper surface preparation, please consult the SAE Aerospace Information Report AIR 4069. This document is available through SAE, 400 Commonwealth Avenue, Warrendale, PA 15096-0001.

Mixing instructions

P/S 860 Class B-1/6 is supplied in a two-part kit. Mix according to the ratios indicated in the application properties section. Mix Part A and Part B separately to uniformity, then thoroughly mix entire contents of both parts of the kit together taking care to avoid leaving unmixed areas around the sides or bottom of the mixing container.

Storage life

The storage life of P/S 860 Class B-1/6 is at least 6 months when stored at temperatures below 80F (27C) in original unopened containers.

Health precautions

This product is safe to use and apply when recommended precautions are followed. Before using this product, read and understand the Material Safety Data Sheet (MSDS), which provides information on health, physical and environmental hazards, handling precautions and first aid recommendations. An MSDS is available on request. Avoid overexposure. Obtain medical care in case of extreme overexposure.

For industrial use only. Keep away from children.

For emergency medical information call 1-800-228-5635.

Application Properties (typical)
Color Part A - Black
Part B - Beige
Mixed - Gray
Mixing ratio by weight Part A: Part B
Base Viscosity 13,000, (1300)
(Brookfield #6 @ 10rpm), Poise (Pa-s)
Application life and cure time
@ 77°F (25°C), 50% RH
  Application life Tack free time (hours) Cure time to 30 A Durometer (hours)
77F (25C) 20 min. <3 8
40F (4C) 20 min. <12 24
20F (-6C) 20 min. <48 96

Performance Properties (typical)
Cure Time 14 days @ 77F (25C), 50% RH
Cured specific gravity 1.60
Nonvolatile content,(%) 95%
Ultimate cure hardness (Durometer A) 45
Peel strength, pli (N/25 mm),100% cohesion
JRF immersion, 7 days @140F (60C) JRF/NaCl-H2O immersion, 7 days @ 140F (60C)
MIL-A-8625 (Anodized aluminum) - 25 (111) MIL-A-8625 (Anodized aluminum) - 27 (120)
MIL-C-5541 (Alodine aluminum) - 27 (120) MIL-C-5541 (Alodine aluminum) - 32 (142)
MIL-C-27725 (IFT coating) - 29 (129) MIL-C-27725 (IFT coating) - 26 (116)
MIL-S-5059 (Stainless steel)* - 28 (125) MIL-S-5059 (Stainless steel)* - 25 (111)
MIL-T-9046 (Titanium comp. C)* - 25 (111) MIL-T-9046 (Titanium comp. C)* - 29 (129)
QQ-A-250/13 (Alclad) - 25 (111) QQ-A-250/13 (Alclad) - 27 (120)
*Primed with PR-148 Adhesion Promoter
Tensile strength, psi (KPa) 380 (2620) - Standard cure,14 days @77F(25C), 50% RH
Elongation, % 250 - Standard cure,14 days @77F(25C), 50% RH
Low temperature flexibility @ -65F (-54C) No cracking, checking or loss of adhesion.
Resistance to hydrocarbons Weight loss : 6.9% - 7 days @ 140F(60C) immersed in JRF.
Flexibility No cracks after bending 180 degrees over 0.125 inch (3.18 mm) mandrel.
Repairability to itself Excellent to both freshly cured as well as fuel aged and abraded fillets.
Resistance to other fluids Excellent resistance to water, alcohols, petroleum-base and synthetic lubricating oils.
Fungus resistance Non-nutrient

Note: The application and performance property values above are typical for the material, but not intended for use in specifications or for acceptance inspection criteria because of variations in testing methods, conditions and configurations.

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