Working with mixed carbon-steel scrap metal

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Is there a possibility of welding carbon steel (bar, rod & other kinds of stock)  - with exact analysis of the steel carbon content unknown in the various pieces?Not sure if it would be a factor in considering the question, but I'm only equipped for O/A welding.Thanks.
Reply:oa is great for carbon steel. the variations wont matter until you get something high enough in carbon( i believe around 5% or more?) that it is not mild steel any more, it is cast iron.
Reply:Originally Posted by weldbeadoa is great for carbon steel. the variations wont matter until you get something high enough in carbon( i believe around 5% or more?) that it is not mild steel any more, it is cast iron.
Reply:its 0.5%, not 5. low carbon (mild) steel contains about .1 to .3, medium carbon steel  .3% to about .5%. above that you start to lose weldability pretty fast (tool steel etc). cast iron is a different animal altogether. (if its cast iron the sparks will be a dull orange for the first inch or so when you hit it with a grinder).i think you will be fine with O/A, the flame is a good pre heater. just don't quench your welds.you might even be able to use a slightly carburising flame with the mild steel rods to increase the carbon content of the weld pool. can someone with more oxy welding experience clarify that?
Reply:Originally Posted by stampits 0.5%, not 5. low carbon (mild) steel contains about .1 to .3, medium carbon steel  .3% to about .5%. above that you start to lose weldability pretty fast (tool steel etc). cast iron is a different animal altogether. (if its cast iron the sparks will be a dull orange for the first inch or so when you hit it with a grinder).i think you will be fine with O/A, the flame is a good pre heater. just don't quench your welds.you might even be able to use a slightly carburising flame with the mild steel rods to increase the carbon content of the weld pool. can someone with more oxy welding experience clarify that?
Reply:Originally Posted by stampits 0.5%, not 5. low carbon (mild) steel contains about .1 to .3, medium carbon steel  .3% to about .5%. above that you start to lose weldability pretty fast (tool steel etc). cast iron is a different animal altogether. (if its cast iron the sparks will be a dull orange for the first inch or so when you hit it with a grinder).i think you will be fine with O/A, the flame is a good pre heater. just don't quench your welds.you might even be able to use a slightly carburising flame with the mild steel rods to increase the carbon content of the weld pool. can someone with more oxy welding experience clarify that?
Reply:im finding several refernces stating that cast iron is between 2%-4%..?