For those of you that don't like the lack of "hardness" of Ross paper mache glue, try adding white Elmer's to the batch. It contains polymers that harden the end results, and should calm your fears a bit. I use Ross exclusively because of its resistance to spoiling, but any methylcellulose glues will work. Another factor in "soft" paper mache is the type of paper used in the sculpture itself. I stopped using newspaper in the 70's and started using paper trimmings from drawing papers and the like. It is a great way to recycle the paper rather than throwing it out, and the sizing in the paper helps the work harden
without adding anything to the glue. It also gives me a white surface that does not need to be gessoed before painting, which is a great time saver. Most paper mache needs to be laminated with many layers, to give a good surface for painting, or the paper mache will get wet with paint and collapse. So my advice to those who are still using newsprint: try a different type of paper!
Hope this helps,
P.S. I thought the members of this list would be interested to know that I'm one of the featured teachers in the new book, Flower Teachers, a look at teachers who began their careers in the 60's and 70's. It is out this fall, so look for it in the NAEA newsletter. It was an honor being part of the project, which gave me a chance to reflect upon 30 years as an elementary level art teacher.