Johnson Mfg. Co. pledges to continue supplying these high quality solid Sal-Ammoniac Blocks, as formerly produced by the L.B. Allen Corp. For nearly 100 years this form of ammonium chloride has been used to promote rapid tinning of soldering irons and forged soldering coppers. Only when using well-maintained soldering irons will the solder being used, flow off the tip to properly fill sheet metal seams