Welder Dave
Senior Member
Never knew about this forum. On cast iron brazing or actually using cast filler rod should both break in the parent metal and not the welded or brazed area. Right at the edge is a fail too. Not much gas cast iron welding is done but it is the best if heat is involved like on a manifold. If heat isn't a factor brazing is a good option. Know a specialty shop that brazed a steel plate onto the side of a Kohler engine block with a hole the size of baseball in it. LOTS of preheat and wrapped in a fire blanket for slow cooling. Put back together and no problems. Balance gear exploded which caused the hole.
For hyd's brazing can work but you need to build it up 3 or 4 times thicker because it doesn't have near the tensile strength of steel. Gas welding hyd. Is good as the heat from the torch stress relieves the steel somewhat. Silver brazing is also good and used a lot on factory steel lines with fittings. O/A welding and brazing is becoming lost art.
For hyd's brazing can work but you need to build it up 3 or 4 times thicker because it doesn't have near the tensile strength of steel. Gas welding hyd. Is good as the heat from the torch stress relieves the steel somewhat. Silver brazing is also good and used a lot on factory steel lines with fittings. O/A welding and brazing is becoming lost art.