Lastek 43 has been developed for the repair of “unweldable” cast iron, where Ni base electrodes do not give a solid bond. The special coating develops a powerful cleaning action. The aggressive arc penetrates through the oxidised or contaminated surface and provides a perfect bond.
Lastek 43 absorbs the carbon from the cast iron and the deposit becomes hard and nonmachinable.
Lastek 43 should be used as a buttering run in the groove made with Lastek 1900.
The beads should not touch. The joint is finished with electrodes such as Lastek 40E, 42E or 41E.
Welding all poor quality cast iron, reclamation on ship motor blocks, oxidised furnace parts, repairing foundry defects for colour match, first layer on cast iron prior to hardfacing (spreader cones in brick extrusion machinery, cast iron gears.)
Weld with a weaving motion in the direction of travel.
During the forward motion the arc bites into the cast iron.
During the backward motion Lastek 43 deposits a droplet on the previous deposit.