  The challenge of accessing specialized adhesives designed for strain gage
applications has been highlighted due to failures in logistic chains, requiring
the exploration of local alternatives. A direct simulation of strain gage
bonding behavior with two steel plates is infeasible due to the unique
construction of strain gages. Therefore, an indirect simulation method,
comparing local alternatives to a widely accepted adhesive, Loctite 496, was
employed in this study. Two potential replacements, Loctite 401 and Tekbond
793, were tested and matched against the benchmark adhesive, with a focus on
the key mechanical properties: Proportional Shear Strain (PSS), Proportional
Shear Stress (PSSt), and Apparent Shear Modulus (G*). Loctite 401 exhibited the
highest G*, suggesting its potential use in strain gage installations if G* is
considered most important. However, Tekbond 793 demonstrated superior PSS,
Maximum Shear Stress (MSSt), and Rupture Shear Stress (RSSt) performance,
displaying linear behavior even without an accelerator. Surface preparation
considerations were also discussed, noting that hand abrading results in double
the surface roughness than using an orbital sander. The study further
identified two main regions concerning failure modes related to Ra, with values
below 0.31 {\mu}m causing significant variations in observed mechanical
properties, pointing towards factors beyond adhesive layer thickness affecting
bond properties. Lastly, the general recommendation is the use of an
accelerator for all tested adhesives, while the use of a surface conditioner
and neutralizer was found to negatively impact adhesive performance.
