mountain construction

I built mine from crumpled up paper in piles, then covered in plaster cloth. Works great. I’m sure your plastic bags will work fine. You just need something under the plaster cloth to give it a base.

The plaster mixture can be just be a standard paper mache mix.  I am sure you can find it in powdered form in several places, probably Michaels or any hobby or art store

I am not sure what people are doing today, but in the old days, people built a light wooden frame for what they wanted, and then went to the hardware store and bought yard of chicken wire, and then cut the wire and stapled it to the frame to create the figure.  Chicken wire is very bendable, so you can bend it into curves and mounds, sharp or mild, to create your completed frame before you start laying the paper mache strips on it.   This process takes several layers of the dipped strips to complete, and requires you to let the layers dry out between applications.   If you get the whole thing too wet, it will sag, rot and never dry out.  Then it will smell and grow mold on it.  It really helps if you can dry it out in an area with a dry heat source, such as a laundry room where you have a big dryer, or the utility room if you have a forced air heat furnace (not a heat pump).

I used this process when I was about 14 to create several mountains and tunnels for my HO back in the day. These things lasted  25 years, and were in good shape when I eventually through them away.

The paper mache mix is nice, because it is pleasant smelling and easily washes off of your hands.

Two things  things to watch out for.

If you go this route, don't buy hardware cloth  (it has the very small square 1/4 inch grids).  It is too tough to bend and shape.  You can use it for covering a large relatively flat area, but that is all.  It also cuts your hands to pieces and costs alot of money.

Also, I don't think you can paint the project with an oil based paint or a water color paint.   (Check me n this.)  I think you have to use a good grade of acrylic or latex paint, put on in very light coats.  Again, if you get the thing soaking wet, it will sag and start to dissolve.

I would imagine that there is today a very modern "synthetic" type of paper mache mix which others can recommend to you.  But, back in the day, we made the mix ourselves.   The ingredients were simple and cheap.  I am sure you can find them online.

And here is an amusing story, demonstrating 14 logic.  I once made a huge dinosaur head for a school project, using paper mache.  I did it in a hurry and it looked great, but it was still damp when I took it into the school.    When I brought it home a few days later, I Just stuck it up in the attic, where I had my train set.   I took a look at it about two weeks later, and was shocked to see that it was covered with spots of blackish mold.    I was really sick at heart about it. 

So, I took it out and set it on top of the trash can in the garage, in a fit of anger.   The next day I was watching t.v., and there was an ad for Lysol spray.  The announcer said, "It kills mold and mildew on contact!"

I went and got a can of it from under the sink, took it outside, set my dinosaur head in the hot sun, and sprayed it down until it was damp.     I then let the whole thing dry out in the laundry room, for a couple of days, and then repainted it.   I hung it on the wall like a deer mount.  The mold never appeared again.   My parents left it there, and it still looked great 15 years later when I came back to visit.  (However, it did smell strongly of Lysol for about the first 5 years.)

Hope this gives you some ideas.

Mannyrock

Wow.  I didn't realize your bags were plastic.  I thought when you said standard bags, you meant brown paper.

So, . . . never mind.  :-)