Originally Posted by Pete VanderLaan
Normally the highest concentration is 70%. get the highest.
Don't put it outside but it's OK to cover the flask with a-non ferrous cover. It needs to happen as just warm It should take two days though. I'd just put it under the furnace around the back. It's not a violent reaction at all and it isn't really pungent either. The gold shot will just keep getting smaller and smaller. The worst part is putting it in the sand and mixing evenly. Take that outside to do. then bring it bck in and cover the sands and put them in a warm place of they'll never dry. Once dry, screen it. The really wash the screen.
Sorry, two more questions now that I have the materials. Let me preface these by disclosing that I got a D in high school chemistry class.. First is: can I cover my boro container with either aluminum foil or saran wrap, or will those materials be compromised by the fumes? Second is: cover or not, do I need to have direct- ventilation going on 24/7 for the days this process will take? Thanks