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MIL-PRF-85285 Coating, Polyurethane, Aircraft And Support Equipment
MIL-PRF-85285 Polyurethane Coating is an aerospace grade, multi-component chemically cured product that forms a film that is resistant to chemicals, solvents and abrasion. This coating has excellent adhesion to most substrates and is recommended for heavy duty industrial applications where a tough, resilient finish is required.
MIL-PRF-85285 Polyurethane Coating is an aerospace grade, multi-component chemically cured product that forms a film that is resistant to chemicals, solvents and abrasion. This coating has excellent adhesion to most substrates and is recommended for heavy duty industrial applications where a tough, resilient finish is required. The combination of all properties of MIL-PRF-85285 polyurethane aircraft paint coating (component, liquid, cured coating, resistance, mixing, application, cleanability, and strippability) along with the composition and solvent content provide the necessary requirements for a polyurethane coating used in the extremes of the naval aviation environment. There are no commercial equivalents that meet the combination of all properties of MIL-PRF-85285.
According to MIL-STD-2161, Department of Defense Standard Practice: Paint Schemes and Exterior Markings for U.S. Navy and Marine Corps Aircraft, MIL-PRF-85285 is the standard topcoat used on all U.S. Navy and Marine Corps aircraft: “Unless otherwise specified by the Program Manager of a specific aircraft, all U.S. Navy and Marine Corps aircraft shall be finished in accordance with MIL-STD-7179. The standard primer coating shall be MIL-PRF-23377 Type I or MIL-PRF-85582 Type I. Type II of both MIL-PRF-23377 and MIL-PRF-85582 is required when the use of tactical grays is specified. The standard topcoat shall be MIL-PRF-85285.” MIL-STD-7179 is the Department of Defense Standard Practice: Finishes, Coatings, and Sealants, for the Protection of Aerospace Weapons Systems.
MIL-PRF-85285, along with MIL-PRF-22750 (Epoxy Topcoat, High-Solids) is the primary coating used on U.S. Navy Aircraft, according to NAVAIR 01-1A-509-2, Cleaning and Corrosion Control, Volume II, Aircraft.
Additionally, MIL-PRF-85285 is used on Air Force aircraft as a primary topcoat, according to NAVAIR 01-1A-509-5, Cleaning and Corrosion Control, Volume V, Consumable Materials and Equipment for Avionics (NAVAIR 01-1A-509-5 dated 01 July 2009, is only intended for use by the Air Force. Navy organizations are not required to maintain a copy) and Air Force Technical Manual TO 1-1-691, Cleaning and Corrosion Prevention and Control, Aerospace and Non-Aerospace Equipment.
Note: please refer to the appropriate technical performance specification, MIL-PRF-85285, and applicable technical documents under the MSDS/Documents Tab.
The coating covered by this specification is divided into the following types and classes:
Type. The types of coatings are as follows:
Type I – Aircraft application (420 grams/liter g/l maximum VOC content)
Type II – Support equipment application (340 g/l maximum VOC content)
Type III – Aircraft and support equipment application (50 g/1 maximum VOC content)
Type IV- Aircraft application with extended weatherability (420 g/l maximum VOC content)
Class. The classes of coatings are as follows:
Class H – High-solids formulation
Class W – Water-borne formulation
The polyurethane coating furnished under this specication shall be in the form of a kit consisting of component A, containing the pigmented polyester resins and solvents, component B, containing the clear, aliphatic isocyanate resins and solvents, and optional component C containing organic solvents for class H. Component B shall act as the hardener or curing agent for component A. The volume mixing ratio shall be as specied by the manufacturer. The coating kit shall be supplied such that the admixed coating consists of the minimum volume specied by the procuring activity. When tested in accordance with 4.6, no component of the coating shall contain cadmium, cadmium compounds, or more than 0.05 percent by weight of lead metal or lead compounds, and the coating shall not contain hexavalent chromium.
All solvents necessary for thinning purposes shall be supplied as part of the coating kit, with the exception of Class W. The resistivity of the solvents shall permit application of class H coatings by electrostatic spray methods. When tested in accordance with 4.6, the maximum VOC content shall be 420 grams per liter (g/l) for types I and IV coatings, 340 g/l for type II coatings, and 50 g/l for type III coatings. Solvents used for class H shall be urethane grade and contain a minimum of water and alcohol. Class H coatings shall be compatible with thinner conforming to MIL-T-81772, type I. Brominated and chlorinated solvents, except for para-chlorotriuoromethylbenzene or equal, shall be prohibited in the formulation of this product.
Sherwin-Williams Aerospace Coatings MIL-PRF-85285 (QPL-85285) Type 1, Class H
General Part Number Conventions
“F93”: denotes lusterless or flat finish
“Y”: denotes color greater than 90% white
“Z”: denotes color less than 90% white
“M”: denotes military color specification per FED-STD-595 (see Documents Tab for further information)
“S”: denotes semi-gloss finish
Lusterless (Flat) Finish: The lusterless finish MIL-PRF-85285 comes in two containers packaged in a 4:1 ratio. The first container consists of a 3:1 mix of Part A (base/color component) and Part C (activator). The second container consists of Part B (catalyst). The standard unit of measure for lusterless MIL-PRF-85285 is a 1.25 gallon kit: 1 gallon of a mixture of Part A and Part C, plus 1 quart of Part B. The following product code convention is used for Sherwin-Williams MIL-PRF-85285 products:
Part A: F93XXXXX (“F93” designates lusterless finish; “XXXXX” designates a specific color formulation)
Part B: V93V26 (Catalyst)
Part C: V93V1 (Activator)
Example: MIL-PRF-85285 color number 37038 has a Sherwin-Williams part number of F93B2026.
Note: one kit of lusterless MIL-PRF-85285 will consist of two containers, not three. Parts A and C are pre-mixed into one container.
Gloss and Semi-Gloss: The gloss and semi-gloss finish MIL-PRF-85285 comes in three containers packaged in a 1:1:1/4 ratio. The first container consists of Part A (base/color component). The second container consists of Part B (catalyst). The third component consists of Part C (activated reducer). The standard unit of measure for gloss and semi-gloss MIL-PRF-85285 is a 2.25 gallon kit: 1 gallon of Part A, 1 gallon of Part B and one quart of Part C. Chemsol offers a 2.0 gallon kit and other alternatives that suit customer demand for gloss finish – in these cases the mix ratio remains the same. The following product code convention is used for Sherwin-Williams MIL-PRF-85285 products:
Part A: YMXXXXX, ZMXXXXX, YMSXXXXX, ZMSXXXXX (“XXXXX” designates a specific color formulation)
Part B: CM0843H81 (Curing Agent/Catalyst)
Part C: CM0843AR3 (Activated Reducer)
Example: MIL-PRF-85285 color number 17925 has a Sherwin-Williams part number of YM01568 (white, gloss finish).
Note: one kit of gloss or semi-gloss MIL-PRF-85285 will consist of three containers. Parts A, B and C are packaged in separate containers.
Primers must be applied under the MIL-PRF-85285 topcoats.
For ferrous substrates, use MIL-DTL-53022C, Type II primer, E90H226. MIL-DTL-53030B may also be used. For non-ferrous substrates, use MIL-P-22337J, Type I, Class C2, E90G203. Testing: Due to the wide variety of substrates, surface preparation methods, application methods, and environments, the customer should test the complete system for adhesion and compatibility prior to full scale application.
Steel: Surface must be clean and free of grease, dirt, oil, rust, fingerprints, and other contaminants to insure optimum adhesion and performance properties. Chemical pretreatment, (zinc phosphate) or DOD-P-5328D was primer, e.g. E90G4, gives the best adhesion and performance results. Where blasting is appropriate, blast in accordance with SSPC-SP6. For optimum adhesion pretreat blasted surface immediately. Prime with wash primer E90G40 within two hours after blasting.
Aluminum: Clean with acidic cleaner or other appropriate cleaner depending on contamination. Pretreat with chromate conversion coating MIL-DTL-5541F, wash primer DOD-P-15328D, E90G4, or anodize per MIL-A-8625F.
Galvanized or other metals: Clean and remove oxidation contamination on surface, followed by treatment with DOD-P-15328D wash primer, E90G4, or chemical pretreat with zinc phosphate. Due to the variability in these surfaces, testing adhesion on each situation is recommended.
Shake color component for 10 minutes before admixing.
Admix by Volume:
4 Parts Component A F93 Series
1 Part Component B V93V26
It is recommended to filter strain admixed and reduced paint before placing material in containers for spraying.
This product can be applied using conventional air spray, HVLP, Graco electrostatic airspray or air assisted airless equipment. Please consult your Sherwin-Williams representative for specific equipment settings.
1. Make sure pots, guns, and lines are purged and cleaned.
2. Mix thoroughly and filter strain before spray applying.
3. Equipment Settings (i.e. Conventional settings):
Spray atomizing pressure: 50-60 psi (3.45-4.15bar)
Pot pressure: 10-12 psi (0.69-0.83 bar) using a 60’ fluid hose (3/8” diameter)
Delivery Rate: 8-10 fluid oz (236-295 mL) per minute
4. Always air-blow and tack-wipe the surfaces to be painted. Electrostatic users: Ensure that the aircraft is properly grounded for potential static buildup.
5. Best application results are obtained by applying two medium wet coats, “tack-off” period between coats is not required.
6. If the dry time between coats exceeds 24 hours after dry to tape, the surface should be thoroughly abraded with 240 or 320 grit sandpaper and/or red abrasive pads.
7. Recommended dry film thickness is 1.8-2.3 mils. Some colors may require thicker films to achieve complete hiding.
NOTE: Application of these product systems requires recommended temperature / humidity conditions and film thickness ranges. The material, hangar, and aircraft skin temperature should be no lower than 55ºF / 13ºC before, during, and after application.
Dry times are based on the dry film thickness of 1.8 – 2.3 mils and mixed according to the mixing instructions identified above.
Air Dry Times (75°F / 25°C and 50% RH):
Tack Free: 3-4 Hours
To Tape: 6-8 Hours
Recoat Time: (maximum: 24 Hours
NOTE: Lower temperatures, heavy film thickness, improper activator range selection and poor air movement will extend the dry time.
Clean tools/equipment immediately after use with MIL-T-81772, Type I. Follow manufacturer’s safety recommendations when using any solvent.
Use clean Ketone–type solvents such as CM0110308 MEK. Do not allow material to cure inside equipment.
Standard packaging is as follows:
MIL-PRF-85285 lusterless finish: 1.25 gallon kit consisting of two containers in a 4:1 ratio. There are three parts to the kit; Part A and Part C are pre-mixed and packaged together.
MIL-PRF-85285 gloss and semi-gloss finish: 2.25 gallon kit consisting of three containers in a 1:1:1/4 ratio. There are three parts to the kit; Part A, Part B and Part C – all are packaged separately. Chemsol also offers a standard 2.0 gallon kit in gloss finish.
Please refer to the Part Numbers Tab for further information.
Custom packaging is available to suit the customer’s needs. Please contact us and let us know how we can serve you.
Federal Standard 595 (FED-STD-595), Colors Used in Government Procurement is referenced as the color definition standard for MIL-PRF-85285. This standard presents the colors used by Government Activities in a format suitable for color selection, color matching and for quality control inspection. This standard describes the designation and use of the color chips of this standard.
Alternatively, Chemsol can color match to any color specified by the customer.