Acid core solders are manufactured with the solder wire as a tube and the center of the tube contains the flux which must be removed after soldering to avoid potential part corrosion. Heat sources for cored solders can be air/fuel torches or soldering irons and guns.
Metal Mender Solder. 40% Tin / 60% Lead.
Acid Core is classified as INH1 per J-STD-004.
New Old Stock
Made in USA
UPC 0 27041 83310 7
Note: What is the difference between resin core and acid core solder?
Rosin flux residue is non-corrosive which eliminates the need for post solder cleaning. The mild nature of rosin core limits its use to copper and brass. The name acid core tells us the flux is an aggressive type designed to solder steel as well as other metals.