TacFlux Fuzan 81-GF is a flux-gel formulated for manual soldering, rework, and repair of printed circuit assemblies, classified ROL0 and compatible with all SnPb alloys and most SAC lead-free alloys. It combines the tack strength of an SMT adhesive with the wetting performance of a soldering flux — with a typical tack strength of 149 g and viscosity of 282 kcP — holding components securely in position until the joint is complete, which is especially useful for rework where parts must stay put without additional fixturing. It supports a wide reflow temperature window, can be reflowed in either air or nitrogen atmosphere, and leaves a residue (typically 36% by weight of the original deposit) that does not require cleaning, since Fuzan 81-GF is used alongside Ostec-Integra's high-purity solder wires and wave/selective soldering alloys. Supplied in 10 cc and 30 cc syringes or 100 g jars, it carries a 12-month shelf life when stored at 0–30 °C; syringes should be dated when opened and allowed to reach ambient temperature before dispensing.