David Nebenzahl wrote:

Why mess around with isopropyl alcohol at all, since all of it
contains *some* water? Use denatured alcohol (methanol) instead, in a
tightly-capped container to guard against absorbing moisture.

Perhaps it is different where you live, but here in the US, denatured
alcohol is not methanol; it is, instead, ethanol with a denaturant added.
The denaturant can be methanol, or it can be any number of other chemicals,
so long as it is sufficiently adulterated to prevent a person from using it
for ingestion.

Jon