Is it no longer possible to repair other players gear?

I'm an Armorer, and a friend of mine a Blacksmith, and we both play Paladins whenever we can. We always cross-crafted, and cross-repaired each others things.

Since phase 4 (didn't test in any earlier tests that I can remember), we've been unable to figure out how to repair other players soulbound gear. Is it a request you can make, akin to materia melding? Perhaps in a trading window...?

We tried, and couldn't find a way. Does anybody know if we can?