Here's a look at the second hillside with some cardboard stapled on. I tried to imitate the stepped layered look of the first attempt
Here I've stapled on some construction paper that was first crunched up into a ball and then unfolded. You'll see I balled up some paper on the top right, to help give the illusion that the rocks continue on
I then covered the paper with dampened shop wipes dipped into a tub of Hydrocal plaster. This isn't the light version. It dries very hard. You could also use paper towels ... they're much cheaper!
Well the whole thing took about an hour's time. I went into the shop and cast some rocks and called it a day. BTW if you mix up too much Hydrocal don't rinse it down the drain!! I have no experience here but have been warned that it will harden in the drain. NOT GOOD! Instead, just keep stirring the plaster as it setup. Keep breaking up the lumps into large pea sized granules. Now save these, don't throw them out you'll need them later. Do this with any leftover plaster you have from your project. It will be used as a filler later.
After trimming up the rock castings with a little hand saw and fitting them roughly into place lets get to the business of mounting them. Strip up some wipes and placed them in a bucket of water. Then mixed up some Hydrocal. Soak the casting and the hillside with a strong spray of water. Now wring out a piece of wipe and dip it into the plaster. I put it on the back of the casting with a little extra plaster and hold it in place for a few seconds. Then Its off to the next. I use the wipes for two reasons."A" It allows me to start setting rock without having to wait for the plaster to thicken and “B”, it makes up the gaps that I get by setting my castings so vertical. I don't care for the look of the casting when they lay against the mountain and away from me. I want them to be straight up and down or maybe a little leaning in to create an overhang. But this crates gapes that need to be filled in. Here's a shot after the castings are attached.
I also use the wipes to fill in all of the lager gaps. Look to the end of the pointer.
Now its time to use the Lumpy plaster as described by Rich Battista. Before you start be warned , THIS IS MESSY! Take the time to cover your tracks layout floor and anything else that can be damaged. Also get a good sized and well functioning spray bottle ... you'll need it!
Take a coffee cup full of the granules I told you to save and add about one cup of plaster to it. Add 1/2 cup+ of water and mix. BTW I use gloves here. WORKING FAST, grab small handfuls of the mix and push it into the gaps. I work from the top down. Use your spray-bottle filled with water to wash of the face of the rock and to rinse away the plaster exposing the granules. Use plenty of water. I sop up the mess with paper towels and a large sponge. Just keep working in small batches. If the stuff sets up, not to worry: just stir it again until its consistency of small granules again and reuse it. Clean up the mess and your done!
Heres some shots of the finished, uncolored hillside:
Ok ... Its color time! Not much to show in the way of work. I used Scenic Express coloring in a spray bottle of about 32 oz of water and just sprayed it on. I used burnt umber, raw umber and slate. After it dried about an hour I had to put down some grass and such. Here's the hillside completed.
I really like the way this system works. The results are too good to be true: just
follow nature, use your imagination, relax and have some FUN !! Good luck !!