AbstractIt is demonstrated that the bonding characteristics of commercial liquid adhesive primers made from nitrile rubbers and phenol‐formaldehyde polymers, cured by means of hexamethylenetetramine can be quite sensitive to the presence of small amounts of excess water and ammonia. The added water partially decomposes the hexamethylenetetramine to formaldehyde and ammonia, the concentration of the latter thus increasing to such a point as to promote a lower temperature curing of the phenolic resin. Restoration of the original adhesive properties can be attained by the addition of reagents which remove either the water or the ammonia, or both, from the adhesive. Examples of such reagents are certain organic acids, anhydrides and peroxides. The addition of these reagents has been found to reactivate and increase greatly the useful lives of nitrile‐phenolic liquid adhesive primers containing hexamethylenetetram