What can I burn in an open cup burner stove?
I'm looking for easily obtained fuels for an open-cup stove, such as a Trangia, in case I need to top up while travelling.
I have a small simple DIY open cup spirit stove, for boiling water when bike touring and I don't want to carry my MSR. I may make a slightly more sophisticated one. I'd normally run it on meths (denatured alcohol), ideally with a little isopropanol added so the flame is more visible (isopropanol burns rather dirtily, unlike ethanol or methanol). Surgical spirit (rubbing alcohol) is based on ethanol and/or isopropanol, but the additives and isopropanol mean it doesn't burn cleanly and leaves an oily mess in the burner.
Meths is available (in the UK) from hardware shops and camping stores, but not reliably from supermarkets or petrol stations, which are more common and open longer. So are there alternatives? As an example, acetone and even ethyl acetate (in the form of nail polish removers) are easy to buy in supermarkets, and if I did have the MSR I could top it up with lighter (Zippo) fuel which can be bought anywhere that sells cigarettes.
For an international glossary of fuel names, see How are camping fuels named in different languages and geographies?