Welding Cast Iron the old way

by Davey
(Bude, Cornwall, UK)

Hi! I was never a full time certified welder but welding was a part of my engineering job and I've done a bit you might say. In fact some welding done by so called "professional welders" I regard as rubbish.

Anyhow in the workshop of the firm that I worked for, a cast iron machine part broke through being overtightened. We had a brazing hearth (not so good since it was converted to natural gas - methane) and we had oxy acetylene. Some old rusty V shaped cast rods also turned up. After vee-ing out the crack the part was heated gently with the old brazing hearth.

Once hot the oxy-acet came into play. The welding rods go pasty and can be pushed into the weld area which becomes pasty with black speckles rather like raspberry jam.

Afterwards the part was kept hot by the brazing hearth to prevent rapid cooling and the flame slowly reduced. Very hot work doing it this way but the part lasted many years until the place closed down. The proper way of doing such jobs was to pack the item in coke or charcoal but we had neither and there was no time to make the box to hold the coke.