Checking epoxy equivalent weight and pot life before changing resin grades

Do similar epoxy equivalent weights justify the same hardener dose?

Equivalent weight expresses reactive groups. Pot life also depends on the curing system, temperature and mix scale.

Track workability and the cured film

Confirm supplied form and solids basis, then calculate the ratio using the hardener’s active hydrogen equivalent weight. Track viscosity and working time at the planned batch size and temperature and retain cured film specimens.

Why do equal-viscosity resins give different working times?

Compare resin structure, hardener, ambient temperature and mixed batch size. Two-component primers: With the specified hardener and substrate, compare pot life, degree of cure and corrosion protection. High-solids coatings: Keep pigments, fillers and temperature fixed. Compare application viscosity, leveling and residue.

Checking Epoxy equivalent weight and Viscosity

Epoxy equivalent weight (g/eq): This grade is reported to ASTM D1652. Determine the reporting basis separately for other forms. Viscosity (mPa·s): 25 °C. The source reports cP, numerically equivalent to mPa·s. Nonvolatile matter (% by mass): Applies to a solution or dispersion. Distinguish it from neat resin.

What to record

• Epoxy equivalent weight
• Hardener equivalent weight
• Batch size
• Mix temperature
• Working window

Technical references

• Aditya Birla YD 128: liquid epoxy resin technical data ↗

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