TINFOIL-MOLD WARGAMING HILLS: QUICK, CHEAP & BETTER DETAILS

Tinfoil Rock Mold, Reusable

Model railroaders have been making cliff faces by pouring plaster of Paris into rock molds since the start of the hobby. A popular hack, was to make a tinfoil mold by gluing several sheets together, wrinkling it in random patterns, then pouring the plaster into it to make thin pieces that could be then broken into whatever shape was needed to construct the rock faces. I used this technique on several terrain pieces, gluing the broken chips to a white Styrofoam base, then using spackle or more plaster to fill in the gaps between the ‘rocks’. This makes amazingly functional and realistic looking pieces for the gaming table and I loved the end result, but gluing all the pieces was time consuming. I experimented with this alternative technique and it proved to be an incredible time saver for these very detailed hills. I have estimated the cost of materials to be less than one dollar for each hill. This is the new technique that I wanted to share.

You start by creating a tin foil mold. They are reusable again and again. Lay out a tinfoil sheet about 18 inches long and smear Elmer’s style craft glue on it. Add another sheet of foil and repeat until you have built up four to five layers. Ensure good surface contact by placing books while it dries. Fold and wrinkle it to simulate a rock face. Long diagonal creases at different angles will appear like elongated cracks or fault lines in the slabs. You can crease up the edges to hold in a quarter to a half-inch deep pour of plaster, or you can continue with the next step.

Choose a piece of Styrofoam that will form the center of your hill. Hills are seldom perfectly round so form it into an irregular shape with slopes for sides. The Styrofoam edges will be covered by plaster so there’s no need to use the good expanded insulating foam. Feel free to use that crappy bubbly white stuff you were going to throw away. Then pat yourself on the back for helping save the environment.

Shape a Styrofoam Core and Weigh it Down in the Center of the Tinfoil Mold

Of the two hills that I made for this project, one Styrofoam piece was two inches thick, the other was a single inch, (I play Battletech with mine, so these are perfect for level 2 and level 1 hills respectively).

Pouring in the Plaster Around the Core

If you want ‘flat-topped’ hills so your miniatures can rest on a relatively level surface, you can save some cleanup time later by pressing some of the creases out of your foil in these areas now. It can also be done by pressing hard on the Styrofoam core to flatten the foil mold beneath it. It doesn’t need to be perfect as you will see later. Press the Styrofoam against the top and weight it down with a heavy object, (I used a brick,) to keep it from floating in the plaster. Now shape the foil up and around the Styrofoam but leaving a gap between the core and the foil walls for the plaster. Remember the plaster is heavy, so crease the edges of the foil together so it doesn’t collapse your mold and leak out. I also put several supports (using various objects) all around under the foil edges to help support the mold’s walls which will want to give under the weight of the much heavier plaster.

Mix the plaster of Paris in accordance to the instructions on the packaging and add in the space between the Styrofoam core and the tinfoil mold. Fill up the mold until it is slightly past the edge of your Styrofoam core. Tap the Styrofoam and the outside of the mold to help release air bubbles in the
plaster. Believe it or not, you can remove your hill from this mold in about an hour. This will assist in drying. I let it sit overnight for good measure.

Pour the Plaster Just Over the Edge of the Styrofoam. Curl the Edges of the Tinfoil so it Doesn't Collapse. It Dries Quickly. 

I used a serrated edged steak knife to chisel off high points on the bottom and carve out the few little air bubbles I had into longer ‘cracks’. Set it on a flat surface and find the high-points that need trimming. I also cleaned up the top surface, fully exposing the Styrofoam core because I knew I was going to cover that surface with flock. Rub the piece down with your hands, and break off the tiny brittle edges before you paint.

Use a Knife to Knock off any Brittle Bits or High Points.

Remove Unwanted Portions and Sharp Edges that are Likely to Break Off Later.

First Coat, Level 1 Hill

Don't Forget to Coat the Bottom Too

Plaster of Paris needs to be sealed or it will leave white, chalky marks where ever you place it. I painted it with 1 part black, 1 part brown (cheap craft paints) mixed with 2 parts Elmer’s glue (PVA) and a very tiny bit of water to make it spread easy. Apply with a large brush. PVA is famous for making hills warp but the plaster will remain ridged so use it liberally to protect your hill. Make it very dark and be sure to get all the recesses which will represent the ‘shadowed’ areas. Don’t forget to seal the bottom with it too. I place it in front of a fan to speed up drying time. It should be done in 10-15 minutes.

Other Coats are Dabbed with a Sponge 

Add some white paint to the paint mix you already made, lightening up the color just a shade. I use a cut up kitchen sponge and dab the slightly lighter gray over 90% of the surface of the hill. Set in front of fan to dry. It should be done in 10-15 minutes. Add white paint again, lightening up the gray, but this time sponge on to approximately 80% of the surface. Don’t try to get the recesses, leave them darker. You are targeting only the higher points. Dry in front of the fan. Keep repeating this process with a lighter shade each time until only the very highest points on your hill are receiving the lightest shade of gray. By the time you are applying the final shade of very light gray, you will only be trying to cover about 5% to 10% of the surface. You could get a satisfactory result with just a few coats but it will look much better with the recommended 6-8 applications. If you use a fan to speed up drying time, you can keep the same paint mix going in between coats, adding just a little white between each one. This will speed up the process and your hills will be finished extremely quickly.

Six to Eight Coats Later, Each Getting Progressively Lighter, Our Gray Hills are Nearly Finished!

There are other painting techniques for plaster of Paris hills using washes. I feel that if you are going to be handling the hill, transporting it to the club and traipsing your minis all over it, the paint really needs the PVA mixed in with it to protect it and keep it from leaving chalky markings.

Add glue to the top surface and flock. If there are any horizontal creases or cracks in your surface where you can imagine grass or weeds growing from, you can place glue there as well and sprinkle with flock. I choose these spots by imagining seeds blowing in the wind and landing on a particular location on the hill. If the seed would take root and grow, I flock that area. If it would roll down the hill and perhaps get caught somewhere else, then I flock that spot instead. This really makes the hills ‘pop’ with eye-catching detail. Water down some more PVA (50/50) and a few drops of dish soap to help break the surface tension and drip or spray it onto your flocked surfaces to seal them. It may appear a bit milky at first but it will dry clear.

Two Finished Hills. Less Than One Hour of Crafting, Not Including Drying Time.

Battletech Miniatures, Trebuchet and Spider for Scale. 

Battletech Miniatures, Trebuchet and Spider for Scale.

Pathfinder Miniature Gnome Summoner, Surrounded by Warhammer 40K Orks

Here's is a Hill I Made by Gluing Plaster Chips to Styrofoam, then Spackled and Filled Between the Gaps. Loose Rocks Added for Rough Areas. Nice Result, but Very Labor Intensive (Over Four Hours of Work, Not Including Drying Time).

The advantage of the tinfoil mold method is that you can create very nice-looking hills with rock details exceeding that which is usually achieved using the expanded polystyrene foams. The finished product has a bit of heft to it and stays in place nicely on the table. I find they helped weigh down my grass mat as well. I can make a pair of hills like the ones seen with less than one hour of labor (minus the drying time, of course). The only disadvantage is that plaster of Paris is a brittle medium when compared to insulation foams and if the terrain is dropped from a significant height, it will probably break, (though I have never broken any). You are also restricted by the size of the foil mold you can make, though larger molds could be made by gluing the sheets accordingly and I plan to experiment further with 'foil skirting' on larger pieces.

None of these techniques are new, but I haven’t seen them combined in this manner which is why I wanted to share them. I may be mistaken, so feel free to post links to your findings or if you discover similar builds, place them in the comments below!

My cost breakdown for these hills was approximately one US dollar each:

4-5 sheets of tinfoil at $0.26 (reusable for several plaster projects)
2 lb plaster at $1.36 (enough for two hills)
Cheap craft paint (black, brown & white) under $0.30
Elmer’s Glue under $0.14
Approximately 1 ounce of Woodland Scenics Flock $0.24

Finally, no one accomplishes anything by themselves and without the help of teachers and
mentors. Gamers are a community and I must recognize that the foundation of my (very limited) terrain building and game craft knowledge comes from the list of amazing Youtubers below. If you have any questions regarding terrain, dungeon crafting, tabletop wargaming, models or dioramas, you will want to check out these channels and support their efforts!

Mel the Terrain Tutor:
https://www.youtube.com/channel/UCx_aro8CTHw7ZD5H661hC6Q

Lukes Aps:
https://www.youtube.com/channel/UCsmD5774MOQhjYBkXqu3Jdw

The Crafting Muse
https://www.youtube.com/channel/UC92IlSbAqZY-TQv5pa4V1nQ

Kathy Millatt
https://www.youtube.com/channel/UCK-tzXpJ-rgXugc-eJfCtxg

Luke Towan
https://www.youtube.com/channel/UCjRkUtHQ774mTg1vrQ6uA5A