Sewers - what is the best way to seal a correded cast iron sewer system that has abs draining into it.?

what is the best way to seal a correded cast iron sewer system that has abs draining into it.?

I tried to seal it with an epoxy and quickcrete but that didn't work am I better off to replace the whole line or is there a less expensive fix?

You could just cut out the bad section of pipe using a reciprocating saw with a special metal cutting blade and put in a piece of abs to fit. Use two no-hub couplings on both ends and you're done!