Home › Blog › Aerospace, Defense & Space › UAVs & Weapons Systems › Material selection
Thermal, Shock, and Aperture Sealing: Selecting Materials for Missile and UAV Hardware
Compact defense platforms concentrate several material problems into a small volume: shedding heat from dense electronics, cushioning those electronics against shock, and sealing antenna apertures without blocking the signal. H-O Products supplies the converted materials for each job and does not design the systems themselves.
This guide walks the families on the missile, UAV, and weapons-systems materials page, from SOLIMIDE foam and aerogel to graphite spreaders, boron-nitride pads, PORON ShockSeal, and the silicone aperture seals, matched to the job each one does best.
Request a quote for your project →
Three material problems in one airframe: thermal, shock, and aperture sealing
Compact defense platforms pack several material problems into a small volume. Densely packed electronics must shed heat with little airflow; the same electronics must survive mechanical shock and vibration; and antenna apertures need sealing that keeps the environment out without blocking the signal. H-O Products supplies the converted materials for each of these jobs; we do not design or integrate the systems themselves. The families below are organized by the three jobs, and every property lives on the maker's data sheet rather than in this article.
Thermal insulation: managing heat and protecting structure
For lightweight thermal insulation, SOLIMIDE polyimide foam offers very low density with thermal data per ASTM C177 / C518 on the TDS, while the aerogel blankets Pyrogel XTE and ArmaGel deliver high thermal resistance in thin sections for hot zones. Where a thin inorganic barrier is needed, mica sheet and ManniGlas glass-fiber paper serve as non-combustible facings and heat shields.
Thermal interface materials: moving heat to the structure
When heat has to cross from a component to a heat sink or the chassis, the thermal-interface families take over. Graphite spreaders, SpreaderShield natural graphite and the eGRAF HiTherm synthetic-graphite TIM, move heat laterally in very thin sections; the boron-nitride silicone families Sil-Pad insulating pads and Gap-Pad conformable fillers bridge gaps between component and sink, with thermal data commonly reported per ASTM D5470 on the TDS. The Protect and Secure pad and film families round out the range.
High-shock cushioning: protecting electronics from transients
Defense electronics see mechanical shock and vibration that ordinary cushioning does not survive. PORON microcellular urethane, including the slow-rebound ShockSeal 4790-79 grade, absorbs a transient event and recovers, which is the property a shock cushion needs as distinct from steady-state vibration isolation. Silicone foam and vinyl nitrile add temperature range and closed-cell sealing to the cushioning job.
Radome and aperture sealing: keeping the environment out
Antenna apertures need a seal that excludes moisture and contamination while staying transparent to the signal, so non-conductive elastomers do the work. Silicone sponge and solid silicone provide the compliant, environmentally stable seal, fluorosilicone sponge adds fuel and chemical resistance where the aperture sees those, and flame-resistant kSil V-0 grades (for example the kSil V-0 70) cover sealing duty with documented fire behavior.
Families by the Job They Do Best
| Family | Best job | Why it is chosen | Data on TDS |
|---|---|---|---|
| SOLIMIDE / aerogel | Thermal insulation | Low density; high thermal resistance in thin sections | ASTM C177 / C518 thermal |
| Graphite / Sil-Pad | Thermal interface | Spreads or bridges heat to sink or chassis | ASTM D5470 thermal impedance |
| PORON ShockSeal | Shock cushioning | Absorbs a transient and recovers; low compression set | ASTM D3574 force-deflection |
| Silicone sponge / fluorosilicone | Aperture sealing | Non-conductive seal; fluorosilicone adds fuel resistance | ASTM D1056; fire data per grade |
| Mica / ManniGlas | Inorganic heat shield | Non-combustible barrier and facing | Thermal and fire per TDS |
Illustrative and relative only; confirm each grade on its current technical data sheet. Job assignments describe common material usage, not system design or performance.
How do outgassing and fire reshape the shortlist?
Two requirements narrow the list fast on compact platforms. Sealed optics and high-altitude bays often call for low-outgassing materials, so grades whose TDS reports ASTM E595 screening move to the front for those locations. And anywhere a part shares space with occupied or fire-sensitive compartments, the FAR 25.856 insulation context and UL 94 flammability classes filter the candidates.
The practical order is to name the zone and its environment first, confirm which candidates carry the outgassing or fire lines on the TDS, and only then compare thermal or mechanical performance among the survivors.
How H-O Products helps
H-O Products die-cuts, waterjet-cuts, laminates, and kits the families above to your drawing in Winsted, Connecticut; we do not manufacture the foams, graphite, or silicones in-house. We die-cut graphite spreaders and gap-filler pads to component footprints, cut shock cushions and aperture seals with adhesive backings, laminate insulation stacks, and kit hardware sets to work orders, all under our ISO 9001:2015 certified quality management system with lot-coded traceability and the maker's TDS on the order.
Frequently asked questions
What materials cushion electronics in high-shock defense environments?
PORON microcellular urethane, especially slow-rebound ShockSeal grades, is the usual answer because it absorbs a transient shock and recovers, which is distinct from steady-state vibration isolation. Silicone foam and vinyl nitrile add temperature range and closed-cell sealing. The right grade depends on the supported mass and the available crush space; H-O converts the cushion to your drawing and the maker's force-deflection data.
How do UAV avionics shed heat without a fan?
Through conduction: a thermal-interface material carries heat from the component into a heat sink or the chassis. Graphite spreaders such as SpreaderShield and eGRAF HiTherm move heat laterally in very thin sections, while boron-nitride silicone pads (Sil-Pad, Gap-Pad) bridge gaps to a sink, with thermal data per ASTM D5470 on the TDS. We die-cut these to the component footprint.
What is a radome gasket, and which materials stay RF-transparent?
It is the seal around an antenna aperture or radome that keeps moisture and contamination out while remaining transparent to the signal, so non-conductive elastomers are used: silicone sponge and solid silicone, fluorosilicone where fuel or chemical resistance is needed, and flame-resistant kSil V-0 grades for documented fire behavior. H-O converts these seals to your drawing; the RF design itself is yours.
Do these materials carry MIL-STD-810 ratings?
MIL-STD-810 is a family of environmental test methods applied to assemblies, not a rating stamped on a raw material. We can point you toward grades commonly used in hardware that targets those profiles and convert the part accurately, but H-O performs no qualification testing and makes no pass or fail claim against a test method. The qualification result belongs to your program.
Does H-O design missile or weapons-system components?
No. H-O Products is a materials converter. We die-cut, waterjet, laminate, and kit thermal, shock, and sealing materials to your drawing and supply the maker's published data; we do not design, integrate, analyze, or test weapons systems, and we make no statement about any system's performance. Program-specific design and certification remain entirely with you.
Get a material recommendation
Tell us the job (thermal insulation, thermal interface, shock cushioning, or aperture sealing), the zone and its environment, and the geometry, and we will recommend a family and quote converted parts to your drawing.
Samples typically ship in 3 to 5 business days for common die-cut configurations on materials we keep on hand; standard production runs about two weeks after drawing approval; expedited service is available. MOQ varies by material and part.
Family-owned in Winsted, Connecticut since 1971 · ISO 9001:2015 certified · OEMs worldwide send us a drawing — and get back their part.
Related reading
Request a quote for your missile, UAV & weapons-system part
Send H-O your drawing or describe the part—engineering reviews every RFQ and converts samples on your geometry.
Last updated · Reviewed by H-O Products engineering (ISO 9001:2015 certified converter, Winsted, CT).
References
- ASTM C177 / C518 (thermal conductivity); ASTM D5470 (thermal impedance of interface materials); ASTM D3574 (flexible cellular urethane); ASTM D1056 (flexible cellular rubber); ASTM D2240 (durometer); ASTM E595 (outgassing screening).
- FAR 25.856 (insulation context); MIL-STD-810 (environmental test methods); MIL-STD-461 (EMI test methods); MIL-DTL-83528 (conductive elastomer spec); UL 94 (flammability classes). Cited by designation; H-O performs no testing.
- Manufacturer technical data sheets: SOLIMIDE polyimide foam, Pyrogel XTE and ArmaGel aerogel, mica sheet, ManniGlas glass-fiber paper, SpreaderShield and eGRAF HiTherm graphite, Sil-Pad and Gap-Pad boron-nitride silicone, Protect and Secure TIM, PORON urethane and ShockSeal, silicone and fluorosilicone sponge, flame-resistant V-0 silicone sponge.
This article summarizes material-selection principles for missile, UAV, and weapons-system hardware using the families and method designations cited on the parent application page. H-O Products supplies converted materials only; we do not design, integrate, or test weapons systems, and nothing here describes weapon performance. Comparisons are qualitative; values are per each grade's current technical data sheet, and no test results are quoted.
MIL and FAR designations are named for orientation only; H-O makes no qualification, compliance, or airworthiness determinations and holds no claim to program-specific certifications. All parts are custom manufactured to order; minimum production run quantities vary by material and part. H-O is a converter, not a raw-material producer.