Look for graduated glass beakers, low form. Then you will get ones with a small rim-like foot that may fit directly or after widening the holder. But you will also find models with a larger, hexagonal plastic foot. Taking off such foot may reveal a rimless bottom, you shall have to test-buy.
Hydrofluoric acid is a weak acid. Organic chemists use it to remove tar from glass reaction vessels. Here it does not dissolve the tar but the glass under it so the crud floats free. Even though HF is a weak acid it necrotizes flesh even after a very brief contact. In that respect it is nasty stuff.
Here it does not dissolve the tar but the glass under it so the crud floats free. Even though HF is a weak acid it necrotizes flesh even after a very brief contact.