I’ve been trying to make Ferric acetate by mixing vinegar with steel wool and allowing it to react. The result is successful in dying leather or wood black and acting as a mordant. Theoretically there are ways of crystallizing, precipitating, filtering, or separating it with solvents.
There is only one problem: I can’t remove it from the vinegar solution without it oxidizing. Adding Hydrogen peroxide causes it to create iron oxide, heating it causes it to hydrolyze and create iron oxide. Leaving it in solution turns some of it into iron oxide.
One idea I had was using glacial acetic acid instead of vinegar but I’m hoping I don’t have to because that’s fairly expensive. I could also do the entire thing under vacuum but it still wouldn’t fix the hydrolysis reaction. Could I maybe crystallize it? I’m open to suggestions with an emphasis on stuff that doesn’t require expensive reagents or obscenely overpriced labware.