DON26BZ05-NV075 TITLE: High Performance Electrolytic Coating Touch-Up Repairs for Aluminum
OUSW (R&E) CRITICAL TECHNOLOGY AREA(S): Contested Logistics Technologies (LOG)
COMPONENT TECHNOLOGY PRIORITY AREA(S): Sustainment
PROJECTED CMMC LEVEL REQUIREMENT: Level 2 (Self)
OBJECTIVE: Develop a simple, cost-effective, and portable touch-up applicator for performing electrolytic conversion coating repairs to provide a robust corrosion protective coating for aerospace aluminum components and structures.
DESCRIPTION: Corrosion protection for aerospace aluminum primarily relies on two inorganic coatings: chromate conversion coating and anodize coatings. Anodizing provides a superior barrier against corrosion, especially in harsh salt-water environments. In contrast, chromate conversion coatings (e.g., Alodine, Iridite) offer less protection but are significantly easier to apply, requiring a simple, non-electrolytic chemical application.
This difference in application creates a maintenance challenge. Anodizing is a complex process generally restricted to depot or Original Equipment Manufacturer (OEM) production facilities. Field repairs on anodized components, which can comprise up to 5% of the surface area under MIL-PRF-8625, often fall back on the use of easier-to-apply chromate conversion coatings. Touch-up pens, in particular, are widely used in aviation maintenance, from large depots to resource-constrained fleet environments. However, when used on an anodized part, these chromate repairs create a point of weakness that is more susceptible to corrosion.
A third alternative, electrolytic conversion coating, has been developed to bridge the performance gap between these two methods. Recent studies at NAVAIR demonstrate that applying a small electrical current (several hundred milliamps per square foot) during the conversion coating process significantly enhances corrosion resistance. Currently, the equipment required for this process restricts its use to depot factories where chemical processing shops are available. This creates a need for a field-deployable solution.
This topic seeks the development of a portable touch-up method for applying electrolytic conversion coatings. The solution is critical for filling a technology gap for a method to apply, repair, and touch-up aluminum coatings at the fleet level, improving corrosion capabilities across all levels of aircraft manufacturing, maintenance, and rework operations.
The ideal solution should meet the following criteria:
The method must prevent chemical spills, environmental release, operator exposure, and contamination of the maintenance area.
The process should be simple, cost-effective, easy to deploy to fleet maintenance sites, and require minimal operator training.
The process should generate minimal hazardous waste, and the equipment should be simplified and miniaturized as much as is practical.
The resulting coating must meet or exceed the corrosion performance requirements of MIL-DTL-81706.
The application method must not damage the underlying aluminum through pitting, fatigue loss, or other undesirable effects.
Primary aerospace aluminum alloys are 2000, 6000, and 7000 series aluminum alloys. However, the application method must perform equally well on all aluminum alloys.
The process must not use hexavalent chromium.
PHASE I: Develop and demonstrate the feasibility of a portable, touch-up application method for electrolytic conversion coatings. The effort will include the following tasks:
1. Design a concept for a portable electrolytic conversion coating application method suitable for touch-up repairs.
2. Prove the viability of the application method, evaluating key parameters such as coating effectiveness, ease of use, and the ability to deposit coatings in tight spaces like fastener holes and other small interior diameters.
3. Conduct initial studies to assess the corrosion performance and paint adhesion of the applied coating.
4. Deliver a final report detailing the design and feasibility results, along with a comprehensive test and development plan for Phase II.
The Phase I effort will include prototype plans to be developed under Phase II.
PHASE II: Develop, optimize, and validate a prototype system for applying electrolytic conversion coatings, focusing on the following key activities:
1. Based on the successful Phase I concept, fabricate and deliver a functional prototype system to NAVAIR for evaluation.
2. Further assess and refine key system parameters, including portability, material compatibility, process costs, and operator ease-of-use. The application method will be optimized to ensure successful coating deposition on a variety of part geometries.
3. Evaluate the coating method to ensure it does not cause adverse effects to the substrate, such as inadvertent pitting, etching, corrosion, or loss of paint adhesion. Conduct testing as applicable to meet the requirements of MIL-DTL-81706 and/or MIL-PRF-8625.
4. Seek additional funding from various sources to support a fatigue testing initiative aimed at generating preliminary data on this touch-up method.
5. Provide a comprehensive final report that documents the prototype's design, system performance, and all material testing results. Include a detailed plan for Phase III.
PHASE III DUAL USE APPLICATIONS: Transition the validated prototype into a fully commercialized, field-ready product for widespread military and commercial use. This phase will focus on the following activities:
1. Operational Demonstration: Demonstrate the system's effectiveness in real-world, on-aircraft repair scenarios on aluminum substrates. Final validation will ensure the product is ergonomic, easy-to-use, and does not cause detrimental effects to the base material or expose operators to safety or hazardous material risks.
2. Transition the finalized prototype into a commercially viable product ready for widespread distribution. This includes finalizing all licensing and intellectual property (IP) agreements necessary for a successful commercial launch.
3. Establish National Stock Numbers (NSNs) for the system, its chemicals, and any required consumables. This will ensure the product can be easily procured and deployed by Department of War (DoW) maintenance activities worldwide.
This technology has direct applications in both military and commercial aviation maintenance. As the use of electrolytic conversion coatings in aircraft production grows, the demand for a portable repair method will increase substantially. Anodizing and chromate conversion coatings are standard for protecting aluminum on a wide variety of commercial platforms, including airliners, helicopters, corporate jets, and general aviation aircraft. Since touch-up repairs are a routine maintenance activity across all types of aircraft, this technology would represent a significant improvement over existing methods, offering a more durable and effective corrosion protection solution for the broader aviation industry.
REFERENCES:
KEYWORDS: Electrolytic conversion coating; ECC; Chromate conversion coating; Touch-up repair; Anodizing; Brush anodizing; Inorganic coating; Aluminum
| 8/31/26 | Q. | The Phase I tasks do not address surface preparation. Should proposers assume standard depot-equivalent preparation (deoxidize/desmut with rinse) prior to coating, or is field-representative surface preparation considered within scope? |
| A. | This is primarily targeted to be a field repair, so please assume field preparation conditions rather than depot conditions. Simplicity in the design of the touch-up process is important. In a field environment, maintainers may be young, newly enlisted people with little technical background. They may be performing aircraft maintenance procedures in accordance with manuals or written instructions, but with no engineering or technical assistance available from others to answer questions or provide guidance. You may assume that the maintenance site has basic materials available, such as sandpaper, Scotchbrite pads, tap water, and standard 120 V electricity, but anything beyond that should be included as part of the technology that is developed. The maintenance site can be located in a wide variety of environments, and so the touch-up method will need to perform well in a wide variety of operating temperatures, humidities, and ambient conditions. | |
| 8/31/26 | Q. | Is the intended reference chemistry a product currently on the MIL-DTL-81706 qualified products list, or a specific NAVAIR-developed formulation? If the latter, is there an established path for licensing or technical access? |
| A. | The prior work done by NAVAIR is based on MIL-DTL-81706 QPL products, and so they certainly would be candidates for this project. But we are not limiting proposals to only these chemical solutions, as we know there are others that may provide strong performance, or would better suit individual companies and their product commercialization strategies. If projects end up using established NAVAIR intellectual property, licensing or technical access can be discussed after the project is selected. | |
| 8/31/26 | Q. | Regarding Phase I task 2 and deposition in fastener holes and small interior diameters: what is the representative repair scenario? Specifically, are these freshly reamed or oversized holes accessible during component rework, or in-situ damage in installed structure? And are they predominantly through-holes or blind holes? Representative diameter and depth ranges would also help scope the effort. |
| A. | In an actual fleet repair environment, the holes could be freshly reamed and oversized, or it can also be in-situ damage that requires repair. The majority should likely be through-holes, although we are not excluding the ability to coat blind holes as that can also be a necessity for some field repairs. Hole diameters down to 1/4th inch can be used. Repairs on other aircraft structures are generally expected to be touch-ups on small surface areas, several square inches in size. The substrate could be bare aluminum, anodized aluminum, or conversion coated aluminum that has been damaged or reworked. | |
| 8/31/26 | Q. | For the corrosion performance requirement referencing MIL-DTL-81706, is the target Class 1A (maximum corrosion protection), Class 3 (low electrical resistance for bonding), or both? |
| A. | Because ECC is a different coating that doesnt have its own MIL spec, we are referencing the current revision of MIL-DTL-81706 due to the similarities ECC has with standard aluminum conversion coating. The current revision of MIL-DTL-81706 serves more as a guideline than as a hard requirement. With that said however, NAVAIR testing shows that corrosion resistance can exceed both Class 1A and Class 3 requirements. 336 hours in ASTM B117 salt fog exposure should be a reasonable baseline expectation for the touch-up method that is developed through this SBIR. | |
| 8/31/26 | Q. | The topic references recent NAVAIR studies applying several hundred milliamps per square foot during conversion coating. In that reference process, is the aluminum substrate polarized cathodically or anodically? The keyword list includes brush anodizing, which suggests anodic operation, while the stated current density is more consistent with conversion coating. Clarification would significantly affect applicator design. |
| A. | In the NAVAIR tests, the substrate was primarily cathodic. Anodic testing was also done, and verified to be possible. These were primarily done in a tank immersion process, and not a touch-up process though. Brush anodizing is referenced as a somewhat similar technology, but the actual applicator in this case would be one to apply ECC rather than an anodizing solution. | |
| 8/31/26 | Q. | Is a chromium-free electrolyte acceptable, or does the Navy expect the trivalent chromium chemistry of the NAVAIR electrolytic studies? |
| A. | A chromium free electrolyte is acceptable. | |
| 8/25/26 | Q. | Q1. The Description references recent NAVAIR studies showing enhanced corrosion resistance from applied current during conversion coating.
(a) Will those studies or their process parameters be made available to selected firms? (b) Should proposers assume a commercially available MIL-DTL-81706 qualified chemistry, or a NAVAIR-developed formulation? (c) If the electrolytic process or its chemistry is covered by Government-held patents, what is the anticipated licensing posture? Q2. MIL-DTL-81706 defines multiple classes and forms. (a) Is corrosion acceptance the standard unpainted 336-hour neutral salt spray panel test, or a repair-representative article such as a reworked or scribed anodized panel with the repaired zone evaluated? Q3. Use case, repair interface, and geometry envelope. (a) Is the primary use case touch-up of reworked or damaged anodize within the MIL-PRF-8625 repair allowance, touch-up of damaged chromate conversion coating, coating of bare reworked areas such as corrosion blend-outs, or all three? (b) Are there requirements for the interface between the repair and the surrounding intact anodize, such as overlap or continuity? (c) What repair area range should Phase I demonstrate, and for the tight spaces named in Phase I, what fastener hole diameter and depth range is of interest, including blind holes and countersinks? (d) Must the method work in any orientation, including vertical and overhead? Q4. Test matrix, surface prep, and Phase I posture. (a) Should Phase I prioritize bare 2024-T3 as the most difficult alloy case, with 6061 and 7075 as the balance? (b) Given the no-substrate-damage requirement, are mild acid deoxidation steps acceptable within a contained process, or should proposers minimize chemical prep? (c) Will the Government furnish coupons, anodized panels, or retired components to selected firms, or should proposers fabricate their own? (d) For paint adhesion, which primer and topcoat system should be assumed, for example MIL-PRF-23377 primer with MIL-PRF-85285 topcoat, and is wet tape adhesion the intended method? (e) For Phase I, is a benchtop demonstration acceptable with portability addressed at the design level, and is substrate-damage or fatigue screening expected in Phase I or deferred to the Phase II fatigue initiative? Q5. Fielding, quality verification, and consumables. (a) How is touch-up coating quality verified in the field today, and does the Government expect Phase I to propose a field-level quality verification method for the applied coating? (b) At which maintenance levels is the capability primarily intended, and is battery operation preferred over assumed shop power? (c) Are there shelf-life, storage, or shipping-classification constraints on consumables at fleet sites that Phase I should design toward, given the Phase III intent to establish NSNs for the system and its chemicals? |
| A. | 1. A. While relevant high-level background information my be shared as applicable, full dataset access and process parameters from the NAVAIR studies will not be released under this effort. The research was conducted specifically for tank immersion processing, whereas touch-up applications would present different challenges. A primary objective of this effort is for the selected company to develop, validate, and optimize touch up parameters and test data tailored specifically to the electrolytic conversion coating application.
B. Proposers may assume a NAVAIR-developed formulation, but they are also welcome to propose and develop their own chemistry. C. If the process or chemistry falls under government-held patents, a licensing agreement with NAVAIR may be established. Specific details regarding the licensing structure and terms will be further defined transitioning into Phase II. 2) A. 336 hours in ASTM B117 salt fog exposure should be a reasonable baseline expectation for the touch-up method that is developed through this SBIR. 3) A. The primary use case could be all three: damaged anodize, damaged conversion coating, or bare aluminum. B.There are no strict interface requirements, such as minimum overlap or continuity distance. The key requirement is complete coverage and corrosion protection of the exposed substrate within the repair zone. C. Typical repair areas for this application would cover a few square inches. When it comes to fastener holes, the majority would likely be through-holes (as small as Ό), although we are not excluding the ability to coat blind holes and countersinks as that can also be necessary for some field repairs. D. A preferred method would work in all orientations. 4) A. Phase 1 should prioritize all aluminum alloys. B. As long as the chemical prep step does not damage the substrate, it would be acceptable. C. The government will be able to provide coupons or anodized panels to selected companies. Aircraft components would be unlikely. D. MIL-PRF-23377 and MIL-PRF-85285 is the standard primer and topcoat system that should be assumed and the wet tape adhesion test is the intended method for paint adhesion. E. A benchtop demonstration would be acceptable to prove the viability of the application method. Phase II will focus on developing and validating a prototype application system, expanding testing to evaluate substrate impact and fatigue performance. 5) A. Current field touch-up operations primarily utilize brush cadmium plating. Quality verification is performed visually by confirming the presence of plating and the characteristic yellow conversion coating finish. While a proposed field level verification method is not particularly expected in Phase I, an ideal chemistry or application process would incorporate a visual indicator to easily verify coverage and coating quality in the field. B. The O and I maintenance levels would be the intended customer through this SBIR. Battery operation and shop power would both be acceptable methods for power. If shop power is used, assume that these shops have standard 120V electricity, but no other special facilities. C. Shelf life would preferably be at least one year. But shelf life stability, along with packaging and shipping classifications will be further explored in the Phase II effort. |
** TOPIC NOTICE ** |
The Navy Topic above is an "unofficial" copy from the Navy Topics in the DoW FY-26 Release 5 SBIR BAA. Please see the official DoW Topic website at www.dodsbirsttr.mil/submissions/solicitation-documents/active-solicitations for any updates. The DoW issued its Navy FY-26 Release 5 SBIR Topics pre-release on August 5, 2026 which opens to receive proposals on August 26, 2026, and closes September 23, 2026 (12:00pm ET). Direct Contact with Topic Authors: During the pre-release period (August 5, through August 25, 2026) proposing firms have an opportunity to directly contact the Technical Point of Contact (TPOC) to ask technical questions about the specific BAA topic. The TPOC contact information is listed in each topic description. Once DoW begins accepting proposals on August 26, 2026 no further direct contact between proposers and topic authors is allowed unless the Topic Author is responding to a question submitted during the Pre-release period. DoD On-line Q&A System: After the pre-release period, until September 9, 2026, at 12:00 PM ET, proposers may submit written questions through the DoW On-line Topic Q&A at https://www.dodsbirsttr.mil/submissions/login/ by logging in and following instructions. In the Topic Q&A system, the questioner and respondent remain anonymous but all questions and answers are posted for general viewing.
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