[It's a very precise hand he's using to get the metal into that thin crack. Slow going. A drip, then wiping off the extra before it hardens. Dripping, cleaning off, rinse and repeat.]

I've had to repair hairline cracks in equipment before. In general, a metal chassis should be replaced if it's on something important — a robot, an Arts Unit, the works — but sometimes a complete replacement is impossible, and a quick fix will have better results. It would take me a number of weeks to completely replace your arm, and I'd need Add's assistance with recalibrating. This should be a sturdy enough fix.

[And there seems to be sentiment here, from what Gnosis has parsed, so he wouldn't dare say "hey a single crack means we gotta just rebuild the whole thing sorry". It still functioned with it. It's sturdier than he thinks it is.]

Granted, I've never fixed a prosthetic arm before, but the principles apply. Technology is something I understand.

[Unlike people.]