IMHO, I would avoid using hydrofluoric acid... :hehehe and just stick with the vinegar or acetone :dunno2:
Hydrofluoric acid is a
solution of
hydrogen fluoride (HF) in
water. It is a precursor to almost all fluorine compounds, including pharmaceuticals such as
fluoxetine (Prozac), diverse materials such as
PTFE (Teflon), and elemental
fluorine itself. It is a colourless solution that is highly corrosive, capable of dissolving many materials, especially
oxides. Its ability to dissolve glass has been known since the 17th century, even before
Carl Wilhelm Scheele prepared it in large quantities in 1771.
[2] Because of its high reactivity toward glass and moderate reactivity toward many metals, hydrofluoric acid is usually stored in
plastic containers (although PTFE is slightly permeable to it).
[3]Hydrogen fluoride gas is an acute poison that may immediately and permanently damage lungs and the corneas of the eyes.
Aqueous hydrofluoric acid is a contact-poison with the potential for deep, initially painless burns and ensuing tissue death. By interfering with body calcium metabolism, the concentrated acid may also cause systemic toxicity and eventual
cardiac arrest and fatality, after contact with as little as 160 cm
2 (25 square inches) of skin.