Use with wire solder. Bottle is 7 oz. and will last a very long time if stored in a cool place with the lid on tightly. If Flux appears thick when opening, just add a little distilled or bottled water and stir it and it will be ready to use. Always wear safety glasses while soldering.Learn how to work with Flux in a safe manner as well as more about storage, disposal, protective equipment, and spill-handling procedures by clicking on the Materials Safety and Data Sheet.