Loctite EA (Hysol) 1C Epoxy - 4oz Two-Tube Kit

Product Name: Loctite EA 1C Epoxy (formerly Hysol 1C) - 4oz Two-Tube Kit

Loctite EA 1C is a modified general-purpose epoxy paste known for its high viscosity, rigidity, and exceptional versatility. Often referred to by its legacy name "Hysol 1C" or as "Torr Seal" in scientific circles, it cures to a hard, ceramic-like finish that can be sanded, machined, drilled, and tapped. It is widely revered for its ability to withstand extreme environments, high temperatures, and vacuum conditions without outgassing.

Popular Applications & Uses
- High-vacuum leak sealing (widely known as an alternative to "Torr Seal" for vacuum chambers).
- Repairing metal, ceramic, and masonry parts that require machining or finishing after cure.
- General structural bonding where a thick, non-sag gap filler is needed.
- Potting and encapsulating components to protect against moisture and vibration.
- Bonding gauge sensors and components in high-temperature environments.

Industries that Commonly Use It
- Scientific & Research (Vacuum systems, particle accelerators, microscopy)
- General Industrial MRO (Maintenance, Repair, Overhaul)
- Aerospace and Defense
- Electronics
- Oil and Gas

Special and Unique Features
- Machinable: Cures to a hard, dense solid that can be sanded, drilled, threaded, and painted.
- Low Outgassing: Suitable for high-vacuum applications where standard epoxies would release gases that contaminate the vacuum.
- High Temperature Resistance: Performs well up to 250°F (121°C) continuously, with intermittent exposure higher.
- Non-Sag Paste: Thick consistency stays in place on vertical surfaces and fills large gaps.
- Environmental Resistance: Excellent resistance to oil, moisture, and solvents.

Key Properties
- Base: Epoxy
- Color: Off-White / Bone
- Viscosity: Paste (~350,000 cP)
- Mix Ratio: 2.5:1 by volume (Note: Tube kits are designed to dispense *equal lengths* of resin and hardener to achieve this ratio).
- Hardness: ~75-80 Shore D (Rigid)
- Shear Strength: ~1,750 - 2,100 psi

Materials Bonded
- Metals (Steel, Aluminum, Brass)
- Ceramics and Glass
- Masonry and Stone
- Rigid Plastics
- Wood

Cure Information
- Work Life: 20 - 25 minutes.
- Handling Strength: 4 - 6 hours.
- Full Cure: 24 hours (72 hours for maximum chemical/vacuum resistance).

Known backups / known substitutes for this product
- Agilent/Varian Torr Seal (The vacuum industry standard, chemically very similar)
- Loctite EA 907 (Hysol 907) - Blue tube, slightly faster general-purpose adhesive.
- 3M Scotch-Weld 2216 (Gray) - For structural applications requiring more flexibility.

Comparison Note
- Loctite EA 1C is the "heavy duty" filler of the epoxy world. Unlike the clear, flowable epoxies you looked at earlier (E-00CL, E-05CL), 1C is an opaque paste that acts more like a liquid shim or putty. It is the go-to product when you need to fill a hole, seal a leak in a vacuum chamber, or build up a surface that will later be machined down to size.