Add 14 drops of liquid hardener per 1 oz. of Fiberglass Resin (or for 1⁄4 can of Fiberglass Resin, use 1⁄4 tube of liquid hardener). Estimate the amount of resin needed to completely saturate the fiberglass material, pour the resin into a clean container (paper cup or metal can) and follow by adding the proper amount of liquid hardener.