I made one out of Fosters Lager cans one time, it burned for a long time. One problem with this type of stove is that alcohol is a low BTU / pound fuel. The stoves also blow out easily, probably okay some place in the world but not anywhere around here.
So by the time you add up the weight of the stove, a wind screen, pot stand, and lots of fuel. You may very well be looking at as much weight as a conventional backpacking stove.