Hi Everyone!
I appreciate all the input on types of plaster. Guess I should have started a separate thread on this so the non-coffee drinkers could benefit from the info.
The top level of hills are covered now, but I have about three times that to do on the 2nd and 1st level. I most definitely will change the type of plaster from "P of P" to one of those recommended. All I am trying to do with this application is to cap the plaster gauze for added strength and also to contour the surface more toward a natural shape. Any rock outcroppings are done with molds or by hand carving added globs of plaster. I would still like to know how the Pro's cover an interior wall of a house with plaster and mix up enough at one time to make progress. Do you think they may use some kind of retardant?
Glenn: Thanks for the info. It would be difficult for me to get over to B'hm in time. I may try to find someone that supplies painters/contractors and see if they have Hydrocal or can order it for me. I first will check Lowes and see if they have molding plaster in the brand Jeffrey and Jim suggested.
Karl: Yup...old school, tried and bonafide!

The first problem for me to using foam is finding foam over 1" thick down here. For anything over 12" high, I would have a lot of layers...too many! Mess??? Man, you ain't seen nuttin unless you saw me trying my hand with foam. There were shavings everywhere: under, over, and flying in the air.
Nothing wrong with foam...I just ain't no good at it!

David: Again, really good to have you back on here. This place along with the hobby is one of the best things going for us to temporarily forget some of the more distressing parts of our world. I have tried the paper towel method and couldn't get enough plaster soaked-in to have the strength I was looking for. I would rather pay for the plaster gauze, then cap it with additional plaster, and quickly get done with those steps. As stated, my detailing of crevices and rock formations are done with added plaster: by mold or carving. Another trick is to add vermiculite to add texture to the plaster surface; you really have to be careful with this as it has a tendency to suck the moisture out of the plaster.
Just a note: The first mountain I built was in Bangkok, Thailand in 1969; materials were there, but hard to find. I stripped some 12awg solid wire and made a form that was a rough shape of mountain. I then crinkled up some alum foil and formed it around the frame. I painted it and wala: not too bad

. The wife reminded me of paper mache (w/flour) and the next attempt used it over the same frame, but covered with window screen. Better!
