Black Heat-Resistant Glue: Incure Heat-Resist™ 320
When a bond line will be visible on a finished product and the assembly runs hot, a clear adhesive that yellows or blooms is a cosmetic liability. Black heat-resistant glue solves both problems at once, and Incure Heat-Resist™ 320 pairs a pigmented finish with genuine elevated-temperature performance. Why Color Matters at the Bond Line Standard cyanoacrylate cures clear but is prone to frosting, or blooming, as monomer vapor settles on nearby surfaces and reacts with ambient moisture. On a dark housing or a machined casting, that white haze stands out. A black-pigmented grade hides the joint, masks minor squeeze-out, and gives line operators and inspectors an immediate visual cue that adhesive is present and correctly placed. Heat-Resist™ 320 is a single-component, medium-viscosity cyanoacrylate that cures to an opaque black film. It carries the same modified chemistry as the rest of the Heat-Resist™ line, so the color is not a trade-off against thermal capability. Incure Heat-Resist™ 320 at a Glance Chemistry: single-component, room-temperature-cure cyanoacrylate, black Viscosity: medium, for controlled placement and small gap filling Fixture speed: seconds to tens of seconds depending on substrate and humidity Bond strength: up to roughly 5,200 psi on suitable rigid plastics Thermal behavior: engineered for thermal-shock resistance and elevated continuous service Chemical resistance: withstands alcohols, aliphatic fuels, aromatic hydrocarbons, and dilute acids and bases Substrates and Joint Design Heat-Resist™ 320 bonds most engineering thermoplastics, elastomers, cured composites, and prepared metals. Keep the bond line thin, between 0.05 and 0.15 mm, and load the joint in shear. Because the film is rigid, add a mechanical feature to carry peak load on any joint that flexes in service. Prime low-surface-energy plastics such as polyolefins before bonding. The opaque film also blocks light, which matters when a joint sits next to an optical path or a sensor window. For assemblies that mix rigid and flexible plastics with a wide temperature range, read how CTE mismatch causes adhesive bond failure so differential expansion does not overload the joint. Application and Cure Control Wipe both faces with isopropyl alcohol and let them dry. Dispense one thin drop or bead on a single face; over-application cures slowly and can still bloom despite the pigment. Mate within the open time, hold light fixture pressure, and allow 24 hours for full strength and peak heat resistance. A brief 80–100°C post-cure speeds the climb to full properties on a production line. Hold shop humidity between 40 and 60 percent for repeatable fixture times. Use an activator on inactive surfaces or where the gap exceeds what the adhesive bridges alone. On automated equipment, meter each shot so the cured film thickness stays consistent part to part. For a broader view of how cure speed and working time trade off, see which adhesive dries faster for quick repairs. Where Heat-Resist™ 320 Fits Consumer electronics: visible seams on dark enclosures that sit near warm power components Automotive: trim, clips, and sensor mounts in the engine bay where appearance and heat both matter Industrial equipment: machinery housings and…