DIY: Bottle Raft | Tinkerer Box Blog

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Bottle Raft

Stem Activities

Ages: 6-8

30 minutes

Grownup needed

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This activity might save your life! If you're stranded on a desert island with some large empty containers, you could make a floating raft to escape! Let's learn how to build one!

Materials Needed

A bowl of stones (or other household weights)
23 ice lolly sticks
Rubber bands
Glue
Pencil
Two identical plastic bottles
A large container that can hold water

An array of items set up on a light wooden table suggests preparation for a science experiment or craft project. A clear plastic container filled with water sits at the back. In front of it are two empty clear plastic bottles, a small bottle of white glue with a blue cap, a collection of colorful rubber bands, a pencil, a neat stack of small wooden craft sticks, and a clear glass bowl containing several rocks. This arrangement indicates a hands-on activity involving water, buoyancy, or construction.

Step-by-step tutorial

Step 1

Place 11 ice lolly sticks side by side and secure them by gluing two additional sticks along the edges. This forms your raft base.

A small raft or platform constructed from wooden craft sticks rests on a light wood grain surface. The sticks are laid side-by-side and glued together, forming a rectangular shape. Two additional sticks are glued perpendicularly along the longer sides, acting as a frame or reinforcement. A finger points towards the lower right corner of the raft. This image likely depicts a stage in a crafting project.

Step 2

Create an "E" shape by placing three lolly sticks horizontally at equal distances, then glue two vertical sticks at their ends. Make a second identical "E" shape.

The capital letter E is formed on a light-colored wooden background using wooden craft sticks. Four sticks are arranged to create the letters shape. Two slightly overlapping sticks form the vertical left side, and three shorter sticks create the horizontal top, middle, and bottom bars.

Step 3

Once the glue on the "E" shapes has dried, place two rubber bands at the ends of the outer sticks on each "E" shape. Check that each "E" shape has four rubber bands total.

The capital letter E is constructed from wooden craft sticks on a light wood background. Two craft sticks, slightly overlapping, form the vertical part of the E, and are bound together with a blue rubber band. A teal or green rubber band is looped around the top of these two sticks. Three additional sticks are positioned horizontally to create the top, middle, and bottom bars of the E.

Step 4

Apply glue to the unattached ends of the "E" shapes (as shown in the diagram).

Two hands work on a craft project on a light wooden surface. One hand holds a structure made of craft sticks, secured with blue and teal rubber bands. The other hand applies glue from a small white bottle to the top of one of the sticks. A separate, completed section of the project, a square made of glued craft sticks, lies on the table to the right. This image captures the process of assembling a craft using wooden sticks, glue, and rubber bands.

Step 5

Turn over the glued "E" shapes and attach them to the raft base at opposite ends, on the side without the two securing sticks.

Two rectangular frames made of wooden craft sticks sit side-by-side on a light wood grain surface. They appear to be connected, or hinged, at the center. Colorful rubber bands are wrapped around the craft sticks on the outer edges of each frame. A blue and green rubber band are on the left frame, and yellow and pink rubber bands are on the right frame. This arrangement suggests a homemade toy or a craft project in progress.

Step 6

Stretch the rubber bands and insert the bottles, ensuring even spacing between the bands. Your bottle raft is now complete!

Hands hold a simple raft or boat constructed from recycled materials against a light wood background. The boat's base is a platform made of craft sticks glued together. Two clear plastic bottles are attached to the underside of the platform, one on each end. Craft sticks are fastened to the bottles with colorful rubber bands—pink and yellow on one bottle, and teal and blue on the other. One hand holds the boat while the other adjusts a rubber band. This image likely depicts a children's craft project or a simple science experiment demonstrating buoyancy.

Step 7

Find a large container filled with water and float your raft. You can also use a sink or bathtub.

A hand holds a small raft made of recycled materials over a clear plastic container. The raft is constructed with a platform of glued craft sticks and two clear plastic bottles attached underneath, one at each end. Colorful rubber bands—pink and yellow on one bottle, and teal and blue on the other—secure craft sticks to the bottles. The container sits on a light wood surface, and it appears to be empty, ready for water or another testing medium. This image likely depicts a science experiment demonstrating buoyancy or a children's craft project.

Step 8

Test your raft by placing different weights of stones or objects on it to see how much weight it can support.

The Science Behind It:

Whether an object floats depends on a concept called "density". When you place an object in water, the water exerts an upward force called "buoyancy". If an object's density is greater than water's, the buoyant force isn't enough to support its weight, and it sinks. Low-density objects like air-filled plastic bottles have a density less than water, so the buoyant force can support their weight, allowing them to float.

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