Use the mixing ratio and measurement basis specified for the exact resin and hardener. A ratio by weight cannot simply be treated as the same ratio by volume. The two components may have different densities, and another product’s instructions do not resolve that difference.
Read the pair of products first
Check both component designations before preparing a mix. A familiar resin name can have more than one hardener option. Meridian’s technical explanation connects weight-to-volume conversion to the densities of the individual components; it is not a reason to invent a conversion for an unidentified kit.
Match the measuring method
A balance measures mass. A graduated container indicates volume. Keep the stated units and ratio beside the preparation record, rather than writing only a pair of numbers. If the instruction gives one basis and the available equipment uses another, obtain the applicable manufacturer information before proceeding.
Retain the actual preparation record
Record the component identities and quantities used for the relevant batch under the production procedure. Keep mixing separate from pot life and cure requirements. Changing the amount of hardener to chase a preferred working time is not a substitute for the specified mixture. A tidy cured surface also cannot reconstruct an undocumented mix.
Further reading: Meridian: epoxy mix ratios by weight and volume.