The knock works pretty well for that, especially since he was in the middle of what is one of the more 'chill out for a minute and watch what happens' stages of what he was working on. It's been cold as hell, and he figured it wasn't a bad time to try and make some arrowheads out of the various bits of metals he'd pillaged from the more destroyed homes. If he's particularly adventurous he might try and make a knife, but he'll see how the arrowheads turn out first, considering he hasn't got moulds for anything yet.

So he's actually on the hotter side of things, and watching hot metal get hotter and trying to make sure the fire stays stoked well enough with this old equipment to keep it malleable for the length of time he might have to wind up working with it. He's not too bad - if you can make a mask, you can make an arrowhead, he figures - but it's been a little while. Although it had been many 'little while's between the last time he did all this and the time immediately before that, but he's not really trying to think about the last time he did all this anyway.

So maybe the distraction is actually welcome. Tony wipes off his forehead with the back of his forearm as he turns to look at who he's already identified, because it's just reflexive to look at her. "Arrowheads. Kind of boring, but in that whole retro, Urban Outfitters kind of way where it's still new? You hate using it, but it's still the in thing at the moment. I'd much rather be working on an automated drone that sends back information regarding the boundaries and constantly maps the apparently-shifting geography of this place, and could even provide helpful information by telling us exactly where it hits system failure, but." He shrugs a little bit, turning enough to locate and then pick up the closest thing to a ball-peen hammer he has access to. "I don't have any silicon."