Most structural epoxies are strong in shear and fragile in peel, so they crack at the edges when a joint flexes. Incure Epo-Weld™ UHB-100 is a rubber-toughened two-part epoxy built to hold high strength while still tolerating impact and vibration.

What UHB-100 is

Epo-Weld™ UHB-100 is the unfilled, rubber-modified grade in the Ultra High Bond family. The elastomer phase dispersed through the cured epoxy blunts crack growth, so the adhesive keeps working after an impact that would shatter a rigid bond line. Compared with the ceramic-filled UHB-200, UHB-100 has a lower viscosity, which lets it wet out tight joints and penetrate slightly porous surfaces before it gels.

Typical service temperature runs from about -53°C to 176°C (-55°F to 350°F). The cured adhesive resists a wide range of solvents, fuels, and dilute acids and bases, and it bonds effectively to metals, glass, and ceramics.

Key properties and what they mean for the joint

• High lap shear and peel strength. Peel resistance is what keeps a bond from unzipping at the edge when the assembly twists. UHB-100 provides both, which is unusual for an epoxy at this strength level.
• Low viscosity. Easier wet-out means fewer voids and more real contact area. It also makes UHB-100 practical for thin bond lines and for filling small gaps by capillary action.
• Wide temperature range. When you bond dissimilar materials, every temperature change loads the joint because the two substrates expand at different rates. A toughened bond line absorbs that movement. The mechanism is explained in this guide to how CTE mismatch causes adhesive bond failure.
• Chemical resistance. The cured matrix holds up to cleaning agents, coolants, and hydraulic fluids over long exposure.

Where UHB-100 fits

• Aerospace and defense: brackets, standoffs, and sensor housings exposed to vibration and thermal cycling.
• Automotive and transportation: bonding trim, sensors, and structural inserts where road input would fatigue a brittle adhesive.
• Electronics and semiconductor equipment: securing subassemblies that must survive shipping and handling shock.
• Industrial equipment and machinery: attaching wear plates, covers, and instrument mounts on vibrating equipment.
• Renewable energy hardware: bonding enclosure components and mounting hardware in wind and solar installations subject to wind loading and daily thermal swings.

Joint design and bond line control

Aim for a bond line of roughly 0.1 to 0.25 mm. Too thin and the joint is starved and stress-concentrated; too thick and shear strength drops while thermal stress rises. Design the joint so the adhesive carries load in shear or compression rather than peel or cleavage, and include a mechanical locating feature so the bond is not the only thing resisting motion. On large flat overlaps, small glass-bead spacers help hold a consistent gap.

If you want a second opinion on a joint before committing to production, Email Us with your substrates, load case, and environment.

Surface preparation

• Steel and stainless: solvent degrease, abrade to bright metal, then a final solvent wipe and full dry.
• Aluminum: degrease and abrade, or use a chemical etch or conversion coating for the most durable bond, since bare aluminum re-oxidizes within minutes.
• Glass and ceramic: light abrasion plus a clean solvent wipe.
• Bond within a few hours of preparation and keep prepared surfaces free of skin oils and shop dust.

Mixing and cure

Meter the two components at the specified ratio and mix until the color and streaking are completely uniform. Off-ratio or poorly mixed adhesive cures soft and becomes the weak link. UHB-100 cures at room temperature over roughly a day to handling strength, with full properties developing over several days. A moderate post-cure at elevated temperature accelerates the schedule and raises the final strength and heat resistance. Keep parts clamped and undisturbed until the adhesive sets.

Failure modes and prevention

• Interfacial failure on metal: almost always contamination or weak oxide. Tighten degreasing, abrade more aggressively, and reduce the delay before bonding.
• Edge cracking under load: the joint is seeing peel or cleavage. Redesign for shear and reduce the bond line.
• Under-cured, rubbery adhesive: off-ratio metering or incomplete mixing. Use calibrated dispensing or pre-measured kits.
• Voids in the bond line: entrapped air from hand mixing or a starved joint. Mix gently, let the mix de-air briefly, and apply enough adhesive.

Choosing between UHB-100 and related grades

Choose UHB-100 when you want a general-purpose toughened epoxy that wets tight joints and resists impact. Move to the ceramic-filled UHB-200 when you need higher stiffness and better dimensional stability, or to a dedicated cryogenic or low-outgassing grade for vacuum and space hardware. For a broader look at when an epoxy is the right choice versus a fast UV-cure adhesive, see which adhesive dries faster for quick repairs and which is stronger for heavy-duty repairs.

Next steps

Matching the grade to your real load case, substrates, and line process gives a more reliable joint than picking on peak strength alone. Incure’s technical team can review your application and recommend a grade and cure schedule. Contact Our Team to get started.

Visit www.incurelab.com for more information.