01 Dec Which Materials Can — and Can’t — be Powder Coated?
A technical guide to selecting substrates that succeed in high-temperature curing environments.
By Hugo Canales
At Royal Coatings, we work closely with purchasing agents and estimators who need absolute clarity on whether a substrate is compatible with powder coating. Making the wrong material choice can create significant rework, scrap, and compliance issues — especially when supplying aerospace and military primes. The following guidance reflects the standards we apply every day in our NADCAP-accredited facility, supported by decades of experience in advanced finishing for Boeing, Raytheon, Lockheed Martin, Northrop Grumman, and other defense contractors.
Materials That Can Be Powder Coated
Powder coating requires parts to withstand cure temperatures of approximately 350 to 400°F. Metals that tolerate this thermal load and can hold an electrostatic charge are ideal candidates for our powder coating processes.
Metals Compatible With High-Temperature Curing
These substrates consistently deliver reliable adhesion and predictable performance during curing cycles:
- Aluminum
- Steel and stainless steel
- Copper and copper alloys
- Brass and bronze
- Titanium
Metals in these categories perform exceptionally well because their dimensional stability is not compromised by thermal cycling, and the electrostatic attraction required for uniform coverage is highly effective on conductive substrates. Royal Coatings applies multiple resin chemistries, including epoxy, urethane, hybrid, and polyester powders, allowing us to match performance characteristics to the component’s operating environment.
Pre-Treatment Requirements
Durability in powder-coated components relies heavily on how the substrate is prepared before coating. Our three-stage phosphate pre-treatment system removes contaminants and improves surface energy, ensuring strong adhesion and complete cure integrity. Depending on the metal, preparation may include:
- Cleaning and degreasing
- Abrasive blasting or mechanical roughening
- Phosphate conversion coating
- Precision masking for critical surfaces
These steps are essential for achieving uniform film build, edge coverage, and long-term corrosion resistance.
Materials That Cannot Be Powder Coated
Many substrates fail under the thermal or electrostatic requirements of powder coating. Early identification of these materials is essential to avoid misquotes and manufacturing delays.
Heat-Sensitive Substrates
Materials that deform, melt, or off-gas at 350 to 400°F cannot be powder-coated. These typically include:
- Plastics and polymers (unless engineered for high temperature)
- Rubber and elastomers
- Wood and MDF (standard in commercial fabrication but rarely acceptable for aerospace or military use)
Because the coating must flow out and cure as a continuous solid film, any structural instability during heating results in severe defects.
Non-Conductive Substrates
Powder relies on electrostatic attraction. Substrates that cannot hold a charge produce poor transfer efficiency and nonuniform film thickness. Common examples include:
- Many composites are used in aircraft interiors
- Ceramics, fiberglass, and glass
- Carbon fiber without conductive primers
These materials may be engineered for strength and weight advantages, but do not inherently support the electrical properties required for powder adhesion.
How Substrate Selection Affects Aerospace and Military Performance
In aerospace and defense manufacturing, coating performance is as critical as dimensional accuracy. Poor substrate selection can compromise:
- Corrosion resistance and environmental durability
- Abrasion and impact resistance
- Thermal stability during mission-critical operations
- Adherence to MIL-DTL, MIL-PRF, or OEM-specific specifications
When a material is incompatible with powder coating, alternative systems must be selected early to maintain compliance. Our team frequently assists planners in evaluating mixed-material assemblies to ensure that every surface meets final-customer standards, whether the requirement is chemical resistance, conductivity, infrared signature reduction, or strict aesthetic uniformity.
Common Engineering Mistakes in Powder-Coat Quotations
Across hundreds of aerospace and military programs, several recurring issues appear during quoting or engineering review:
- Specifying powder coat on assemblies with heat-sensitive inserts or electronics
- Underestimating dimensional changes from film build
- Specifying aluminum alloys with surface contamination or improper temper for blasting
- Calling out powder coating on non-conductive composite housings
- Overlooking masking requirements for grounding surfaces or threaded features
Engaging a qualified coating provider early prevents avoidable redesigns and contractual changes.
Alternatives When Powder Coating Is Not Viable
Royal Coatings provides a complete suite of finishing solutions so that incompatible materials still receive the correct engineering treatment. Depending on thermal limits, chemical exposure, electrical requirements, and OEM standards, we frequently shift customers toward:
Liquid and Mil-Spec Coatings
Our liquid coating systems meet a wide range of federal and military specifications, including MIL-PRF-85285, MIL-DTL-53039, and numerous other high-performance finishes. These coatings cure at significantly lower temperatures, making them suitable for heat-sensitive substrates while still delivering corrosion resistance, controlled film thickness, and color matching.
PTFE and Teflon Coatings
When friction reduction, chemical resistance, or high-temperature stability is required, PTFE and Teflon-based systems offer a superior solution. Their non-stick, thermally resistant, and chemically durable characteristics make them ideal for demanding aerospace and military components.
CARC Coatings for Defense Applications
For military hardware that requires chemical-agent resistance, infrared-signal reduction, and mil-spec compliance, CARC coatings remain essential. These coatings are engineered specifically for mission-critical defense systems and cannot be replaced by powder coating in those applications.
Ensuring Compliance Across Mixed-Material Assemblies
Many aerospace and defense assemblies combine aluminum, stainless steel, composites, elastomers, and electronic components. Our NADCAP Chemical Processing accreditation ensures that we select and apply the correct coating systems for each material without compromising environmental durability or specification compliance. This includes coordinated masking, selective finishing, and processing sequences that prevent thermal damage to sensitive components.
Conclusion
Selecting the correct substrate for powder coating is essential for maintaining structural integrity, coating performance, and contract compliance in aerospace and military programs. When powder coating is appropriate, our team at Royal Coatings applies it with the precision required for mission-ready hardware. When it is not, we guide customers toward the right alternative — whether that means liquid finishing, PTFE, Teflon, or CARC systems.
To discuss your substrate requirements or request a technical review, visit our powder coating services page.
As Vice President and General Manager of Royal Coatings, Hugo Canales brings over a decade of proven leadership in the powder coating, liquid coating, and advanced manufacturing industries. Hugo oversees a team of more than sixty skilled professionals, ensuring every project—from military and aerospace applications to medical and commercial equipment—meets the most demanding specifications for quality and precision.
With a background in City and Regional Planning from the University of California, Davis, Hugo combines strategic thinking with a deep technical understanding of industrial processes. Since joining Royal Coatings in 2017, he has guided our operations to consistently deliver MIL-SPEC coatings for major defense and aerospace contractors, including Raytheon, Lockheed Martin, Boeing, and Northrop Grumman.
Hugo’s leadership is grounded in a strong commitment to excellence, safety, and pride in workmanship. His approach fosters a culture where every team member values craftsmanship, precision, and integrity in every finished surface. Under his direction, Royal Coatings continues to uphold its reputation as a trusted partner in the nation’s most critical manufacturing sectors.