Nokorode cold weather flux is a lead free, soft soldering paste flux especially formulated to stay soft and sticky in cold weather applications. It is ideal for use with 95/5 and other common solders. It cleans and fluxes the joint area all at one time. When heated, it reduces the surface tension in the joint and allows the solder to flow easily and uniformly into the joint. Nokorode cold weather flux works to deliver a strong, leak-free joint. It's non-aggressive formula is ideal for use on copper and brass fittings.