My rusting takes 4 to 6 days total wtih about 8 hours or more between coats and carding.. My FECL4 etching solution is about 10% and I typically etch after about 5-6 coats and boil in water only. Then I usually brown and card 4-5 times more, etch again and boil in Logwood and Ferrous Sulfate. My Logwood are chips and not powder.