Current Projects chat and miscellany

I think it's 753 that can't be repaired then-do you know why? And when they talk about air 'curing' steel after it's been built what do they mean?

753 is very sensitive to heat cycle, it might be hard to take a frame apart without damaging it.

The 'air hardening' of 853 refers to the fact that it hardens on natural cooling after welding, rather than needing the cooling rate to be accelerated (quenching)