The idea here was to use rice mortar to build a small castle out of river stones.
Step 1: Gather Materials
Pieces of plywood
Blender or the ability to mash rice
Step 2: Making the Rice Mortar
First you make the rice. Follow the directions for the rice you use.
For the rice I used I boiled two cups of water and added one cup of rice. I let the rice reboil, and let it simmer until cooked thoroughly. I used a magic bullet blender and blended the rice 1/4 a cup at a time. If you put too much in at one time it will not blend well. After blending I put the rice mortar into a seal-able container. Make sure the container seals or you will lose moisture and the mortar will not be of any use.
I made the mortar the day before and refrigerated it. If you leave it out it is bound to go bad. It worked okay having been refrigerated. If anyone uses it while still warm I would be interested to know how well it worked. It was much more goppy warm than cold.
I chose not to mix the rice with anything to keep it easy to make, clean, and safe for the kids to handle. You could add borax to keep mold out, but if you keep it dry that should not be a problem.
Step 3: Building Your Castle
I used the spatula/plastic knives to spread the rice mortar out. This allowed me to press the rice onto the pebbles to ensure good adhesion.
The other method I used was to put the rice mortar into a baggie and cut off a corner of the bag. This allowed me to squeeze it out. My kids really liked using the bag. They preferred it over the spatula/plastic knife method. The bag was also useful for filling in any gaps that needed more mortar.
We started with an outline of what we wanted our castles to look like. Then we applied rice mortar along the outline. Then we pressed the stones into the rice mortar. Be sure to use larger stones on the bottom. If it is top heavy it will fall over. As we built up we would put the rice mortar on the stone to be placed and press it into position.
Be careful while building. The rice mortar does not hold it together until it has had time to dry. After 24 hours or so it should be pretty dry.
This project was really fun and easy. My seven and five year old both had fun doing it. If you like this project let me know. Thanks for the comments.