A bond line rated to withstand 572°F sounds like a single spec until the joint also needs to block light, absorb a thermal-expansion mismatch, or stay electrically insulating while it moves heat — and no single formulation does all of that at once. Incure’s Epo-Weld™ ultra high temperature line splits that range across seven grades, each built around a specific function rather than temperature resistance alone, since the ceiling temperature is really just the starting requirement every grade in this line already meets.
Chemical Resistance at 572°F Anchors the Line’s High End
UHTE-5320 and UHTE-5325 are functionally the same formulation under two catalog numbers — both clear-amber, two-part epoxies at Shore D84–D94 hardness, 20,000 PSI flexural strength, and 2,900 PSI tensile shear, cured either 2 hours at 200°F plus 2 hours at 325°F or 3–4 hours at 300°F. Their high cross-link density is built specifically to resist chemical penetration and swelling from acidic and alkaline solutions, steam, solvents, and salt spray while holding bond strength to 572°F (300°C) — a combination aimed at chemical process equipment and aerospace assemblies that see aggressive chemistry and heat at the same time, not just one or the other. Both grades also meet NASA outgassing requirements, relevant for any assembly destined for a sealed or vacuum enclosure.
Opacity, Flexibility, and Cure Speed Set the Rest of the Line Apart
UHTE-5313 takes a different approach entirely: a black, alumina-filled epoxy formulated for optical opacity rather than chemical resistance, blocking ambient light to prevent optical noise and signal degradation in potted sensors and opaque-bonded automotive components. At Shore D85–D95 and 9,200 PSI tensile shear — the highest tensile figure in the line by a wide margin — it cures faster and cooler than the chemical-resistance pair, at 2 hours at 100°F plus 2 hours at 150°F, or 4 hours at 125°F. UHTE-5321 goes further in the opposite mechanical direction: a single-part, flexible contact adhesive with no fixed hardness or flexural rating, purpose-built to bond dissimilar substrates with mismatched coefficients of thermal expansion without cracking or delaminating as the joint heats and cools. Its cure schedule is the fastest in the entire line — roughly 18 minutes at 180°F followed by 30 minutes at 350°F — a genuine advantage on a line running tight cycle times, though it trades away the rigid load-bearing numbers the other grades carry.
Filler Chemistry Splits Thermal and Electrical Function Across Three Grades
UHTE-5322, UHTE-5382, and UHTE-5391 all use filler chemistry to solve a thermal or electrical problem rather than a pure mechanical one — the same pattern Incure’s thermally conductive epoxy line uses at lower service temperatures. UHTE-5322 is aluminum-filled for straightforward thermal conductivity in heat-sink bonding and thermal-probe fabrication, and it’s the only grade in the line offering a room-temperature cure option (24 hours at 77°F, or 2 hours at 200°F if oven capacity is available) rather than requiring elevated heat throughout. UHTE-5382 swaps in aluminum nitride filler — a ceramic that conducts heat while remaining electrically insulating, the same filler-driven trade-off behind Incure’s TC-9051 grade — making it the choice where a heat-sink bond also needs to avoid becoming a current-leakage path near live circuitry. UHTE-5391 pushes electrical insulation further still: an alumina-filled structural adhesive engineered for dielectric strength and ceramic-to-metal bonding in high-voltage insulation and vacuum-feedthrough assemblies, where the requirement is holding off electrical breakdown under structural load rather than moving heat at all.
Email Us with your service temperature, substrate pairing, and whether the joint needs electrical isolation, and Incure’s engineers can confirm which Epo-Weld™ ultra high temperature grade actually fits.
Cure Schedule Spans Minutes to Hours
Choosing between these seven grades means checking cure schedule against production throughput as much as checking the mechanical spec sheet. UHTE-5321’s roughly 48-minute total cure sits at one extreme, suited to a line that needs parts back in fixturing fast. UHTE-5320 and UHTE-5325’s multi-stage schedule — up to 4 hours split across two temperature steps — sits at the other, reflecting the deeper cross-linking that chemical resistance at 572°F actually requires. UHTE-5322’s room-temperature option is the outlier that trades cure speed for avoiding an oven step entirely, useful on lower-volume runs where equipment availability matters more than cycle time.
Where the Line Fits
Chemical processing and aerospace equipment bonding draws on UHTE-5320/5325’s combined heat and chemical resistance for joints that see both stresses simultaneously. Optical sensor potting and opaque component bonding in automotive assemblies relies on UHTE-5313’s light-blocking fill and high tensile shear. Dissimilar-substrate joints — ceramic-to-metal, glass-to-metal, or any pairing with a real thermal-expansion mismatch — favor UHTE-5321’s flexible, fast-curing chemistry over a rigid grade that would eventually crack at the interface. Power electronics heat-sink bonding splits between UHTE-5322 where electrical isolation isn’t required and UHTE-5382 where it is, the same conductive-versus-insulating distinction Incure’s thermally conductive epoxy line covers at more moderate service temperatures. Vacuum feedthroughs, high-voltage insulation, and aerospace structural assemblies favor UHTE-5391’s dielectric strength wherever the joint has to hold off electrical breakdown under load. Facilities already running Incure’s Epo-Weld™ high-temperature epoxy line for structural work below 572°F, or the ultra high bond epoxy line for vibration-prone joints, can step up to this line specifically where the service temperature itself is the limiting factor rather than shock resistance or peak rigidity.
Contact Our Team to confirm the Epo-Weld™ ultra high temperature grade for your substrate and service temperature.
Visit www.incurelab.com for more information.