We decided to use a yoga ball as concrete mold! It is difficult to find a large sphere mold so we came up with this idea! I hope this instructional video is helpful!
Small hose and valve ( to deflate the ball )
Small tub for mixing the thin set
Trowel Bucket- To stabilize your yoga ball
Thick rubber gloves
Acid Stain for concrete
Plastic spray bottle
Adhesive mesh– In a large roll – To cover the ball
Adhesive mesh– In a small roll- To wrap around the large mesh- to hold in place
Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.
Step 1: Applying Mesh and Thin Set
We tried a few different techniques to in terms of how to place the adhesive mesh around the yoga ball. Cutting large strips and securing them around the wire hoop gave us the ability to wrap the mesh around the ball with little folds.
- Use a smaller roll of adhesive mesh (2-4" wide works great) to wrap and secure your large pieces around the ball. Once you have this part down you can begin to apply your thin set to the mesh.
- Mix your thin set with water and stir with a trowel until smooth. You need to have enough water to be able to achieve a smooth consistency however it is important your mixture is still thick.
- Start applying with gloves and smooth over with a small trowel.
- Apply at least 3 coats of Thin Set. The thin set will need to dry between coats however it dries quickly. Thin set is the same medium you use for laying tile.
Step 2: Acid Stain!
Note: Acid Stain is what it sounds like.... Not something you want to get on your skin, clothes, or any other part of you. Be sure to wear gloves, glasses, and follow safety procedures on the bottle.
For the dripping technique as seen in the photo and video. We (carefully) poured the acid stain into spray bottles then sprayed the top of the mold and let the colors drip down. The first few sprays Farouk blended the stain with his glove to give the ball a washy paint base. Then he kept on adding layers of smudged stain in a few other areas to keep building that base. Finally you sprayed the top of the ball to let the acid drip down the sides creating a great finish.
The end of the video shows him applying the acid stain.
I hope this was helpful! Thank you- Tala Ramadan