I have never dealt with 4130"A", always 4130"N" in repairing vintage aircraft structures.
Why is there a need to heat treat 4130"N", when you can remove the embrittlement by pre-heating and post heating the weld when TIG or MIG welding it? I never suggested a huge savings over DOM or even 1020. It is a marginal gain for the cost increase.
I think we are in agreement, just coming at it from different directions. And the day I quit learning will be the day I die.
