Easy cheap rock faces

Nate

     Excellent info. The quick drying time of plaster makes this go fast. I have added real dirt and greenery at the end with spray glue to hold in place after the dullcote.

Ray Marion

Pardon a stupid question,I never did this. Can you use Joint compound instead of plaster? Could you imbed real stones into the plaster for a more irregular look?

Dale H

Ray

I'll be adding all that later when i get the rest of the cliff painted, wont put to much on the cliff side it self tho.

Dale

When i made my first O gauge layout my dad and I made a tunnel and covered it in compound, and i used the tin foil. It worked but putting compound on that thick takes way the long to dry and cure. I can get compound so easy with work but plaster is the way to go in my mind.

Nate...thanks for the old school tip...

Dale...one caution I have in using joint compound is its shrinkage and then cracking if to thick when wet, as opposed to layered.

I have been experimenting with adding portland cement and white or wood glue to the joint compound and using paint to thin it...jury still out on the amounts...

Dale

      I am thrilled I can offer you advice as your electrical advice has been very useful. The "plaster" is superior over the regular joint compound as it will not shrink and hardens in less than an hour. I believe structolite or hydrocal take longer. They are more expensive but will reproduce a molds high detail better than this regular plaster.

     Although it will set faster, lightweight drywall mix is soft and designed for thin layers.

    Jeff"s suggestion in mixing colors is interesting as acrylic paint will not bother the mix too much. It just seems easier to paint it later. I have no experience with glue or portland as additive.

     I don't see any problem adding natural rock to any mix. Just keep in mind your setting time limit. Hope this helps. If you don't like what you did, it is not that big a deal to start over.

Ray Marion

Thanks guys for your input.

I restored an old building and repaired a lot of plaster with joint compound,that is the reason I asked. I would mix it with sand and water then brush on Wellbond glue for adhesion before applying to the old surface.  This worked very well as a plaster repair,texture refinish but I put it on in layers,about 1/8 inch or less. It has  been on 5 + years now so far with good results.  Only place that sells plaster I know of is Home Depot,Lowes does not carry it. I do not mind using it ,the only problem is you have to work fast.I assume it is the scratch coat plaster?

I am not far enough on the new layout yet but eventually I have to make some rock banks to separate the 2 levels of the layouts. So I have been reading here to get ideas. i am also considering modeling a wooden retaining wall.  Can metal screen or lath be used for a form?  Here are a couple of pics,the surface is painted Quietbrace,recommended by Forum members here.

Dale H

Single sheets of foil are very flimsy and are hard to hold a shape so what I do is to layout a foil sheet and lightly spray with adhesive.  Next I apply a very thin sheet of tissue / wrapping paper to the aluminum sheet.  I respray the tissue with the adhesive and apply a second sheet of foil and smooth out.  I let this sheet joining setup (just a couple of minutes) and then I do the wrinkle bit just as previously described.  Then I spread it back out a little and pour in the hydrocal.  After just a few minutes it will start to get very warm and start to set, that is when I apply it to the layout and finish making the rough form I want.  With hydrocal you can remove the foil as soon as it hardens which is about 15 to 20 minutes.  I also do this process without applying to the layout just lay it plaster side up and let harden.  Then I break this up into smaller pieces to use as filler.  To fill in between the applied pieces I just make a slurry and brush it on to fill in the cracks.  Very fast system and you can make them as varied as you wish.  Have fun.  Russ

Dale

     Several suggestions. If you plan on running Lionel or MTH command, I believe the wire meshing interferes with the signal. Aluminum tunnel liners doe also. One method is to weave 1 inch cardboard strips held in place with hot glue. Use plastic window screen or wide self adhesive drywall mesh and plaster over this. It will be strong enough to add anything you want to represent. More plaster, rock molds or rocks etc can be attached when dry or wet. The mesh is easy to pierce if you plant trees through the shell.

  I made molds with latex for stone walls and matching portals. They take a while to create but pay off with the ability to reuse. India ink in alcohol is the base color.

     Another wall I made was to use the foam board with paper on the outside. I peeled one layer off and used a concrete paint with ink for weathering. 

      It looks like you will need a lot of wall so these may help. Pics attached.

Ray Marion

I think Im going with layered 2" foam.  Ive been messing with the foam and used thin layers of drywall compound to do some custom filling in of the foam, making choppy edges with it.  I create blobs, when its just dry enough, not completely dry, break it apart and you have broken edgy pieces that you can glue on the foam "rock shelf" to make small stuff.  I have glued pebbles also after the painting is done.  I got some pebbles from Jo-Ann store. they sell bags of small irregular rounded stone pebbles.  works good to scale. 

Thanks all you guys for the ideas and taking the time to explain. I am still digesting it all. I never made scenery and the layout plan is for a toy train section and a realistic scenery section. I am running conventional so signal problems are not an issue. The layout should run automatically using relays. There will be 5 loops and 2 trolley lines. Each loop will run 3 trains except the innermost which will run 4 with a passing siding, 2 in each direction. 

Dale H

Dale

   Don't be afraid. This plaster method for rocks and hills is easy. The painting with colors has no wrong choices. I am sure you have untapped artistic talent waiting to be tapped. Good Luck

Ray Marion

I have been using both plaster and the joint compound but not as a mix. I did find a joint compound at Home Depot that has worked out well. No shrinkage or cracking, this is a dry joint compound and the label says it does not shrink or crack, so far so good.

Ray

Great old school idea.  I did this 30 years ago but with a slight variation.  I cut heavy duty tin foil in 6 inch squares then crumpled it into a ball and then opened it back up again and rolled the ends up about 1/2 inch.  sprayed the mold with Pam, a release agent and then filled the mold with Hydrocal.  Let it stand until the watery mix was gone and stuck it to the mountain side.  Removed the tin foil in another minute and there you had a rock formation.  Next mold was stuck along side of it right up against the finished one and this was done to the entire side of the mountain.

Enclosed is a finish picture of the mountain that has been standing since the mid 80's.  I also did other mountains with actual molds I purchased.

Some great ideas.

Gents,

Not to be a "Debbie downer" but introducing a "metal element" such as aluminum foil into the mix....won't that potentially give you problems with legacy/command signal similar to if you used metal lathe/chicken wire within the scenery? It could be tough to connect ground wires to aluminum foil to tie into your earth ground.

Just food for thought.

Nick B.

Boston Metro Hi-Railers

Dear Debbie Downer (LOL)  I mentioned in my article about using aluminum foil then I REMOVED the foil after the hydrocal set up.  My method does not leave aluminum in or on the mountain or anywhere on the layout.  The actual sub shell for the mountain was used the old way of using cardboard strips interlaced together and then laying 6 inch pieces brown paper bags soaked in hydrocal on that sub structure.  After that set up then the aluminum foil molds were used to set the hydrocal and then the foil was removed.  This is one of the oldest methods in my book of doing mountains the cheap easy way.  I get 100 pounds of hydrocal at my local dealer for $50. and I have approx 300 pounds on my layout.  No shrinkage like plaster and dries very quick.

The only aluminum left on my layout are the beer cans while doing this job or running the layout.  Maybe I should switch to brown bottles (LOL)