I wanted to take a try at papercrete. Cement/Concrete with recycled paper pulp. There are a lot of examples of using it to fabricate bricks for building and for art. I guess I could have built a mini papercrete mixer but how about just jumping in and using cement mix as the glue for papier mache? I needed some decorations for the garden but I was not geared up to do concrete casting nor did I want to get into forming armatures or wireforms from rebar and wire mesh. Strolling down the home center aisle, there are many cement products to use. They had this Surface Bonding Cement/Quikwall product that is composed of cement mix and reinforcement fibers. It is supposed to cure to be water resistant to some degree too so it would be good for the final product to be outdoors. This would be perfect to experiment with. It was also about $20 bucks a bag so relatively inexpensive to see what it was capable of. It is a proprietary mix that would probably be difficult or more costly to make on your own.
CAUTION: Read the instructions that come with the cement/concrete mix. Follow directions for use and safety precautions.
Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.
Step 1: Rock, Paper, Scissors...
Some things to think about...
1. Concrete or cement products don't actually dry. They take a very long time to cure which is a chemical process. Some concretes can be cured submerged in water.
2. Which brings us to this, don't attempt a big concrete project a few days before the deadline to enter the concrete contest. It'll cure when it wants to.
3. Concrete is heavy. Getting a 50 lb bag home from the store may be a chore.
4. Concrete depends on having enough water around to cure properly. Too much or too little affects the quality of the concrete. It is as much science as it is an art.
5. The supporting structure or form should be water resistant and strong enough when wet to hold up to the concrete. Which means raw cardboard not so good. Use rigid foam cut from sheets/blocks or spray on.
6. Concrete is highly alkaline. Anything embedded in it should resist the chemicals in cement/concrete. It is tough on exposed skin. Wash with vinegar to neutralize the reaction. Wear rubber or nitrile gloves when working with concrete.
7. Try not to breathe the dust or particles from the concrete powder. Use a dust mask and full clothing.
8. Mix with power tools if you can. It is hard work.
9. When mixing or using, concrete splatters all over the place. Do outdoors where you can be messy.
10. Almost like playing with mud, a little more funner.
11. Cement is the term properly used for just the binding agents. When mixed with aggregates/stone/sand to give it strength, the mix is concrete.
12. You never want a pair of cement shoes nor do you want to deal with anyone who wants to make you some.
So what do you need to get started?
A bag of cement mix, I used the Surface Bonding Cement. You might be able to improvise with the other sand topping mixes, acrylic fortified patching cement, stucco mixes, essentially the stuff without the big rocks and gravel.
Mixing implements that will be stuck with cement residue afterwards. You shouldn't really clean up in the sink if you want to prevent any major repair clogs. Rinse off with a garden hose outside and capture runoff to dispose of properly when dried.
Plenty of newspaper and cardboard.
A heavy duty stapler or lots of tape.
Utility knife or heavy duty shears to cut the cardboard
Rubber or nitrile gloves to protect your hands.
Dust mask and safety glasses as additional protection.
Step 2: Freeformwork...
Like in all papier mache, you need a base shape to apply the papier mache skin. Instead of using regular glue and water for our binding agent, we will use our cement mix.
As you can see, I wanted to make a general outline shape of a Totoro with umbrella. The details I would add on by sculpting with the papier mache material.
Cut out the base pieces of the feet and the tail to define the starting size of the Totoro.
From there, cut out strips of cardboard and just start building up the birdcage frame.
I put intermediate strips or pieces of cardboard in the center between outside strips to strengthen up the structure.
Add as many as needed to keep the structure rigid.
Just get the rough framing done. It will be smoothed out with the papier mache.
I should get one of those handheld packaging staplers since my bookbinding stapler was hard to maneuver between the slats to staple. A regular staple doesn't have enough power to go through thick cardboard and hold when stapled.
You could hot glue but that would be a lot of hot glue used.
Stuff the structure with balled up newspaper.
Step 3: Papier Machecreting
I don't know if there is a term for what I am doing but I am sure someone probably has done the same thing. I will just call it papier mache with concrete, machecreting. Papier mache with cement, well, that would be confusing.
Mix up a small batch of the surface bonding cement. Add just a tiny bit more water to make it lobster bisque or Boston clam chowder soupy. There might be a slight tradeoff in final strength but it will still be sufficient for ornamental and not structural purposes.
Tear up strips of newspaper. This provides the bulk filler of the shell and to hold the cement mix in place until it sets.
The way you are supposed to use surface bonding cement is to coat adjoining bricks or blocks with a thin layer. When cured, a fiberglass stranded mat forms in place tying everything together.
Since cement is heavy and has particles of fine sand and rigid strands of fiberglass, saturated newspaper tears easily and literally melts in your hand to a glob of paper pulp.
I had tried to soak 4 layers of paper to lay as the base coat of papier mache. Sometimes the wet cement mix will not penetrate so the best method is to slather on some surface bonding cement. Lay on a piece of newspaper. Rub it down. Slather on some more cement. Repeat. Overlap all pieces. Repeat and repeat until you feel a thick layer forming. Use the cement mix for a final outer coating. Rub down all the loose fibers.
The touch up and patching work I did used torn paper shopping bags for material. Heavy brown kraft paper works well instead of newspaper. Ask for paper instead of plastic at the Organic Trader supermarket place for paper shopping bags, of course, grocery purchase may be required.
As you can see, I was doing fine and pretty much had one side finished.
Then the moisture soaked into the cardboard internal supports. Things started sagging so I was forced to wait overnight until the one side hardened up enough to roll over to do the other half. I patched together all of the broken pieces by coating it all over with cement mix.
Step 4: Wait and Wait...
You can add details by forming small pieces of saturated newspaper. Tack on with some cement mix and then coat it with a bonding outside layer to blend in with the rest of the body.
I thought about wrapping the whole form in plastic wrap and then the wet skin would just lay over the cardboard form. I wanted the skin to stick to the internal structure but it may have worked if I had done a smaller section first. Make sure you have plenty of support structure underneath as wet cement mix is heavy.
You know when the cement starts changing to a lighter color that it is getting hard and curing. Mist with water often from a spray bottle to keep the cement hydration process going so it cures better.
I had a tough time with the arm holding the umbrella.
What I had finished used most of the 50 lb bag of cement mix. This figure is about 3 feet tall. Yup, that statue is heavy.
I will need to get another bag of mix to finish coating the umbrella disk part and patch the bottom. Test all the areas on the statue to make sure that it is all solid and coated well.
UPDATE: The umbrella part came out pretty heavy. I got a one foot long piece of rebar to insert as the connecting pin between the umbrella disk and the arm tube which is like a pipe to receive the rebar. The umbrella does twirl when it is attached to the arm. I may fix it in place with some caulk or plug it fast with more concrete. With the umbrella installed, it did tip over a bit so I just filled out and extended the footing below it. I wanted Totoro to be free standing so I did that mod instead of relying on a stake in the ground for support, but I don't know how he holds up in hurricane winds or earthquake prone areas.
P.S. Now that Totoro is out in the wild in the garden, anyone that takes Totoro on a traveling gnome adventure, please post often so that we know he is okay and having a better time then he would at home keeping an eye on the weeds that grow taller and taller each season. Also, he may require the extra overweight/oversize baggage handling fee on select airlines, I do not expect to see the bill. Toodles.
Check out the things they are doing with "cement cloth". Emergency shelters and ground covers for erosion control. There, a layer of dry fine concrete is packed between layers of reinforcement material. Saturate with water to set. Kinda what this project is with newspaper but doesn't contribute to the high strength which is the job of the fiberglass fibers.
So give it a try. Maybe start out smaller...or bigger. Concrete canoes, concrete dragon-boats...I do need to make the other forest spirits.