What is the correct method to crimp alum lugs and ferrules?
Work with alum cable has some specific peculiarities. Alum surfaces are subjective to air influence and they get acidized in few minutes. This acidized layer on the surface is of very low electrical conductivity. That is why it is important to rough up the wire with a wire brush and apply silica-vaseline paste immediately after removing of insulation from the cable. If the wire is of triangle-shape, it should be rounded by crimping with dies НМ-300-C made by KBT. The inner surface of a ferrule should also be treated with silica-vaseline paste. It is important to remember to use as little time as possible to complete the crimping to avoid any acetifying of the alum wire.