goldanalog said:
I do recognize the dangers, and really did not want to get even this far. I just have too many other interests and thought this could be easier.
Your other interests are probably easier. Everything we do is hazardous. Dangerous acids, fumes, wastes, etc. Even for an experienced refiner, while it may be "easy", it is never without risk. We try to do our best to minimize those risks by thoroughly understanding what we're doing before we start a process.
I need to know more about what covering it will do. Cover it with a book? These items were glass vases for plants and although they have a flat even top they don't have lids made for them.
You cover it to keep other junk from getting into the solution, and to keep any living creature from being exposed to it. A loose covering will suffice. A simple example would be to put your containers on a flat, solid surface, safely out of harms way, and put a 5 gallon bucket, upside down, over the top. Put a rock or a brick, or something similar on the bucket so the wind or a critter doesn't knock it over. Do not breath any trapped fumes when you eventually remove the bucket.
"For example, when you dilute an acid to make a lower concentration, you never add water to acid, you instead add acid to water. It may seem at first that it shouldn't matter, but adding water to acid creates a hazardous situation, so adding acid to water is safer."
That is a good rule of thumb. Do you understand why? Not trying to be a jerk here, but it's good to know why these "rules" exist. It allows us to apply them when appropriate.
The prime example is sulfuric acid. When concentrated sulfuric acid is added to water, it creates a LOT of heat. This can create a localized boiling action in the water where the acid is being added. This boiling can expel very hot, quite concentrated sulfuric acid onto you which can absolutely ruin your day, if not your life.
In the case of the mix you have, you have a somewhat dilute solution of acetic acid and hydrochloric acid. Adding water to it, while it may generate heat, will not be so vigorous as to boil and create the hazard mentioned above.
The question would be why add water. There is no need in your current situation. Cover it loosely, as it is, store it in a safe place where the fumes will not affect anything around it, and it will be fine.
Dave