I've been avoiding a task for some time now because it had required too long of a time commitment. Rather than find a ten-hour window of time, I found a way to do a smaller bit of the work.
I have been doing the tile work for the new bathroom and have completed the floor part, but the tub enclosure remained. The mortar comes in a 50 lb bag and not only does it provide enough material for a whole day of work, it is also a bear to mix in the winter time.
What I decided to do was divide the bag into 6 parts since the whole bag requires 6 quarts of water. One 6th is 8 1/3 lbs. This is too much for the kitchen scale and too low for the bathroom scale. A solution was hinted-at by the recollection that we have a set of 8 lb dumbbells. A four foot board and a triangular piece of wood later, a serviceable balance was formed.
I did two 8 lb batches of tiling and feel like the project is back on track.