Product Overview
LOCTITE SF 7387 is a single-component activator formulated especially to trigger the curing process of LOCTITE toughened acrylic adhesives. It features a transparent amber liquid composition with solvents such as n-heptane and isopropanol that promote rapid wetting and activation of surfaces.
By applying the activator to one or both bonding surfaces prior to adhesive application, users can achieve accelerated fixture times—meeting demanding production-line requirements while maintaining bond strength on challenging or passive substrates.
Key Features & Benefits
-
Ultra-low viscosity liquid: Enables deep penetration into fine gaps and surface irregularities, ensuring better activation of the bonding surfaces.
-
Optimised for toughened acrylic adhesives: Specifically designed to initiate and enhance cure for the compatible LOCTITE acrylic structural adhesives series (e.g., 330, 331, 332 etc.).
-
Accelerated cure and fixture speed: Reduces fixture time significantly when compared to un-activated surfaces, improving throughput and reliability.
-
Widely applicable substrates: Effective for metals, composite materials and other surfaces where standard adhesive cure may be slow or incomplete without activation.
-
Straightforward use in production: One-component activator—no mixing required—making it practical for automated or manual bonding operations.
Applications
-
Surface Preparation: Ensure bonding surfaces are clean, dry and free of heavy oil, dust or coatings. Remove contamination if needed — unclean surfaces may compromise activation or bond strength.
-
Activator Application: Apply LOCTITE SF 7387 to one mating surface (or both for large gaps or difficult substrates). A light spray or brushing of the liquid is typical.
-
Evaporation: Allow the solvent carrier to evaporate for approximately 1-5 minutes (depending on ambient conditions) until the surface is wet but not excessively solvent-rich.
-
Adhesive Application and Assembly: Apply the compatible LOCTITE toughened acrylic adhesive to the second surface or as directed. Immediately assemble parts (ideally within 15 seconds) and clamp/hold until fixturing is achieved.
-
Curing & Handling: Follow the adhesive’s cure profile; the activator accelerates the process but does not replace the adhesive’s full cure schedule. Allow full strength before putting assembly into service.
-
Maintenance/Storage: Store the activator in its sealed container, in a cool dry place (ideally 8-21 °C). Due to high flammability and low viscosity, avoid exposure to heat sources, oxidising agents, open flames or direct sunlight.
Tips:
-
For substrates that are very passive (e.g., anodised aluminium, composites) or when gaps exceed ~0.4 mm, consider applying activator to both surfaces for maximum effect.
-
Ensure minimal time delay between activator application and adhesive assembly to avoid surface contamination or activation loss.
-
Confirm that the chosen adhesive is compatible with the activator; use of untested combinations may lead to unexpected cure behaviour.
FAQs
Q1: Can SF 7387 be used with any adhesive?
A1: No — it is formulated specifically for LOCTITE toughened acrylic adhesives. Always verify compatibility and refer to the adhesive’s TDS.
Q2: Does the activator itself cure or bond?
A2: No — the activator does not cure or form a bond by itself. It serves to prep the surface and initiate the cure of the companion adhesive.
Q3: What is the optimum time between activator application and adhesive assembly?
A3: Assembly should be done promptly after activator application — ideally within ~15 seconds for best results. The activator remains active for a limited period (up to ~2 hours in certain conditions), but surface contamination may reduce effectiveness.
Q4: Are there safety precautions?
A4: Yes — height flammability, low viscosity and solvent content mean the product should be handled in well-ventilated areas, stored away from ignition and oxidising agents, and used in accordance with its SDS.
Q5: Does this product improve bond strength or just cure speed?
A5: Its primary benefit is to accelerate reliable cure and reduce fixture time, especially under challenging conditions. While it supports stronger bonding on problematic substrates by improving activation, overall bond strength still depends on surface preparation and the adhesive selected.
