To save money on materials, we were only plastering small areas at college, walls and ceilings that were small enough that you could easily get both coats out of a one bag mix. the job I was doing that caused me so many problems with multi was the same sort of thing. an area small enough that you could get both coats out of a single bag mix.
but the question is, if you have 20 minutes to get the first coat on and then start the second coat, how do you find time (on your own) to mix up another bag before the first coat starts going off?
I am fast enough to get one coat on in 20 minutes or less, but mixing up a second mix in that time is a little bit tricky.
maybe I'm just not used to working on my own, I've always had someone else mixing for me since I left college so I could just concentrate on getting the plaster on, the next mix would be prepared while I was still working with the first mix.
But if you only need one bag, and you have enough time to get both coats out of one bag, what is the point of mixing twice?
surely that just wastes time doesn't it?