The Rust Race

Our video!

Purpose / Application

The purpose of our experiment was to test which liquid rusted rebar (steel) the most over the course of 8 days. We hypothesized that the salt water would rust the metal the fastest because the electrolytes in the water would trigger the reaction faster than the other liquids. Also, we hypothesized that the spray-on rust preventer would work the best in preventing rust because it was professionally developed for this task. We did our project because the topic and science behind rust fascinated us. An experience that helped inspire our project was when one of us went to California and noticed that a lot of vehicles there had little to no rust compared to those in Canada. Older cars, and even some new ones, have a noticeable amount of rust due to the harsh weather conditions, as well as the road salt used in the winter. We were trying to figure out the best way to protect your metal products in moist environments and help extend a product's lifespan. Our findings could benefit lots of people, from people who collect antique cars, to construction workers who use their tools outside, or in bigger ways like building design. By preventing rust and extending the life of products, we reduce waste, which will help the planet in the long run.

After we decided on our project, we listed numerous possible liquids that might rust metal, and discussed and researched the reasons that they might have an effect on the rusting process.  After our research, we cut our list of liquids down to 6 because they all had different qualities and should have different effects on the rusting process.  We chose rebar as our metal because it has a high iron content, which is a main component in the rust formula (Fe2O3).

We chose these liquids because…

Melted Snow: We were curious what effects unfiltered water versus filtered water would have on the rusting process.

Distilled Water: We wanted to see if having no minerals in the water would affect the rusting process.

Lemon Juice: We chose lemon juice because it has high amounts of citric acid, and citric acid is a corrosive agent.

White Vinegar: We chose white vinegar because it is a natural rust remover, and we wanted to see if it would not rust at all (because it's a rust remover) or if it would rust a lot.

Salt Water:  We chose salt water because it has electrolytes in it, and electrolytes act as a catalyst to speed up the rusting process.

Chlorinated Drinking Water: We used chlorinated drinking water from our town water system because we wanted to see the effects of treated water on the rusting process.

We submerged the steel in the various liquids for 8 days, with observations being taken every 2 - 3 days to determine how much rust had built up, with which liquids, and with which protective agents.

For our different preventatives, we used motor oil and a store-bought rust preventer. The reasoning behind the motor oil is that it is a well-known DIY solution for problems with rust, so we decided it might work well. We used our store-bought rust-preventer because it was the only anti-rust product available to us at the time our experiment took place. In our testing, we used six liquids: melted snow, distilled water, lemon juice, white vinegar, salt water, and chlorinated drinking water.

We left the pieces of rebar in the jars for eight days, taking observations every two to three days.

Observation Day One

On our first observation day, nine jars had no rust.

Three of the jars that had no rust had preventive on the rebar.  The liquids for these were melted snow, lemon juice, and white vinegar.

Two of the jars had motor oil on the rebar. The liquids in these were lemon juice and white vinegar.

Finally, there were four jars with store-bought rust protector on the rebar that had no rust on observation day one; the liquids in these jars were distilled water, lemon juice, white vinigar and melted snow.

Observation Day Two

On our second observation day, rust had developed in a number of the jars that previously had none, leaving a remaining total of three of the jars with no rust.

One jar had no protectant on the rebar, and two of the jars had store-bought rust protector on the rebar.

The jar with no protectant on the rebar had white vinegar, and the jars with spray-on rust protectant had distilled water and melted snow.

Observation Day Three

Finally, on our last observation day, only two of the jars had no rust*, and they were all from the store-bought rust protector category, and the liquids in these jars were distilled water and melted snow.

Note *One jar in the store-bought rust protector category (chlorinated drinking water) did have visible rust, but it was not a weighable amount*

Main Findings

At the end of our experiment, we found that the store-bought, professionally developed rust protector did what it was supposed to do and protected the rebar the best.  The motor oil, even though it’s a known DIY, did not protect the rebar like we had hoped; all of the rebar that was protected with motor oil developed rust to some degree.

In the end, our hypothesis was proven partly correct and partly incorrect. In our hypothesis we stated that the jar with the salt water solution, with the rebar that had no protective would rust the most.  We thought this because in salt water there are electrolytes, which help form a catalyst around the rebar helping to trigger the rusting reaction faster.  The salt-water solution (with no protectant on the rebar) ended up developing rust in the mid-range of our results, and the piece of rebar that was kept in lemon juice and protected by motor oil proved to rust the most of all of the jars.

The part of our hypothesis that was proven correct was that the pieces of rebar coated with spray-on rust protectant would rust the least.  The jars that had rebar with rust protectant, which were soaked in distilled water, melted snow, and chlorinated drinking water, had a three-way tie and produced zero grams of rust when filtered.

What we found was that the less expensive DIY solution of motor oil, unfortunately, did not work at all.  The jars with the motor oil “protecting” the rebar rusted the most, so it’s confirmed to us that it is best to use a product that is professionally developed, even if it’s a bit more expensive.

Next Steps

If we were to do this project again, we would add more independent variables (more liquids and more protectants). We would also weigh the pieces of rebar before and after the experiment to get a more accurate and clear result in the end. When we were doing our research, we noticed that most of the options for rust protectants where oil or chemical based. Our next steps would be finding a more eco-friendly way to prevent against rusting

Thank you so much to our teachers...(left to right)

Robert Brooks (teacher)

Matthew Wilson (teacher)

Sophie Baker (teacher)

And also to....

Charlotte Maxwell

Samuel Maxwell

Matthew Eldridge

Leigh Eldridge

Ryan Eldridge

And most of all to...The Rideau St. Lawrence Science Fair Committee.

Thank you all so much for all your help!

References

Breslin, Wayne (Dr.). (2022, Feb. 22). How to Write the Formula for Rust. YouTube. https://www.youtube.com/watch?v=qxXPYdvskJo

Britannica Editors (2025, April 8). How Does Metal Rust?. Encyclopedia Britannica. https://www.britannica.com/science/How-Does-Metal-Rust

Elangperdana Tyre Industry.  (2025, Feb. 13). Signs of Car Corrosion. https://www.eptyres.com/news/details/signs-of-car-corrosion

Grammarly. (2026). (*used for grammar and spell check only) https://www.grammarly.com/

Howstuffworks. (2023, Sept. 8).  How Does Rust Work? science.howstuffworks.com/question445.htm

Mid Continent Steel and Wire. (2022). Understanding Rebar: The Different Types of Steel Used. mcswusa.com/what-kind-of-steel-is-rebar/

Poskin, Ashley. 5 Tried and True Methods for Removing Rust from Metal Objects. (2025, Oct. 2). www.apartmenttherapy.com/how-to-clean-rust-off-old-loaf-141206

Today’s Homeowner with Danny Lipford. (2024, Oct. 14). Revive Rusty Tools With This Vinegar Soak. YouTube. https://www.youtube.com/watch?v=tZ9ngODt_4U

U.S. Centres for Disease Control and Prevention. (2024, Feb. 6). How Water Treatment Works. https://www.cdc.gov/drinking-water/about/how-water-treatment-works.html

Wikimedia Foundation. (2018, Nov. 16). Rust.  https://en.wikipedia.org/wiki/Rust

Wikipedia. (2020, Mar. 13). Iron oxide. https://en.wikipedia.org/wiki/Iron_oxide