Welding Rod
Making your own rods
We take 3/16 concrete steel covered with waste calcium carbide from acetylene generator using vinyl glue as binding agent.
It smells like burned plastics but we weld patrol blades (SAE 1070) very good.
Potassium silicate is good glue for basic flux. Is necessary to use DC welder.
Any binding agent is good also wheat flour.
Question is calcium carbonate gives CO2 in electric arc to maintain plasma and calcium with ferrum makes slag to protect chilling avoiding hydrogen fragility from air moisture.
Silica is for better slag and cleaning agent.
In your blue glasses you can look arc and slag process.
Enlarging rods
You can mix calcium carbonate with any binding agent.
Then "painting rods" you cover it.
Potassium silicate is very good glue also sodium silicate used for cardboard.