solder, weld, leg armor, greaves
銲 centers on joining metal parts: soldering or welding. The leg armor sense is a specialized application where metal plates are joined or fitted to protect the shins.
銲 combines 金 (metal) with 旱, which likely contributes the sound. The character is associated with metalworking processes like soldering and welding, and by extension metal protective gear.
Metal 金 is joined by heat 旱 (imagine the sun 日 on a dry 干 surface) to solder or weld pieces together. The same metal joining idea extends to leg armor made of connected metal plates.
For カン, picture a metal can being soldered shut: can -> カン, and the hot metal seals the joint.