Rusty nail experiment : Fizzics Education


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Rusty nail experiment

Rusty nail experiment

Follow FizzicsEd 150 Science Experiments:

You Will Need:

  • 6 Test tubes or plastic cups
  • 6 Steel nails (avoid galvanised ones)
  • Coke
  • Water
  • Lemon juice
  • Vinegar
  • Cooking oil.
  • Optional: Saltwater, detergent.
  • Adult supervision


Rusty nail experiment - materials needed
1 Rusty nail experiment - Nails in 6 different treatments

Set up the 6 test tubes or cups as shown in the picture above. This experiment is very much about variable testing!

2 Rusty nail experiment - different screws & nail to test

Take a photo and write down your observations of each nail at the start of the experiment. This is also a good time to enter this into your own classroom blog!

Optional: Weigh each nail with an accurate scale at the start and the end of the experiment.

Optional: Try different nails in the same liquid… do they rust differently?

3 Rusty nail experiment - making observations

Over the coming days take recording of each nail’s condition.

– Which nail showed rust first?
– If you were able to weigh each nail at the end of the experiment, was there any difference between the nails? Why?

4 Rusty nail experiment - nail in vinegar on day 1

This setup is just one way of running this classic rust experiment. You could also try the follwing experiment conditions too:

– nail completely submerged in water vs. half submerged.
– nail completely submerged in water with a layer of oil over the top of it.
– nail in salt water vs. nail in pure salt


5 Rust formed on the nail in vinegar

You could also try normal steel nails vs. steel wool to investigate the effect of surface area on rusting rates as well.

6 Students in blue uniforms holding up their hands with green slime dripping from them

Why Does This Happen?

Rusting is the oxidation of metal, whereby the oxygen in the environment combines with the metal to form a new compound called a metal oxide. In the case of iron rusting, the new compound is called iron oxide… also known as rust!

This science experiment is all about controlling variables to explore which material will rust an iron nail first.

Variables to test

More on variables here

  • Try boiling the water… does this make the nail rust faster, slower or is there no impact on the rusting time?
  • What happens when you use different liquids?
  • If you scratch the nail first, will it rust faster or slower?
  • What if you use iron wool and iron filings instead?
  • Try galvanised nails

Learn more!


15 thoughts on “Rusty nail experiment

    1. Hi Kolwawole!
      Thanks for your question. The time to rust for the nail is highly dependent on the liquid the nail is immersed in. In water, you tend to see the beginnings of rust within a couple of days or so whereas other liquids take longer. Try the experiment out and let us know your results!

  1. I bought non galvanised steel nails (they are called bright steel) and I have had them in my liquids (salt water and tap water) for a week now and instead of showing signs of rust they have just gone a grey colour. Do you know why? How can I adjust the experiment to make them actually rust? Thanks

    1. Interesting! It looks like that if your nails were non-galvanised, it would have been to do with dissolved minerals such as carbonates in your water. The more carbonates, the ‘harder the water’. The harder the water the more difficult it is to rust a hot-dip galvanised nail as it affects the pH and the action of sodium and chlorine ions that come from the dissolved salt in the water (see this link). The thick layer of Chromium and Zinc on the galvanised steel slows the rusting as it prevents oxygen reaching the metal (at least for a while). You can actually see this affect by scratching off part of the galvanised layer and then letting this area rust as you’ve removed the protection (read up on crevice corrosion).

      The thing is, your bright steel nails are non-galvanised. This means they should have little to no protection to the salt. If left for longer, the nails should begin to corrode on the outside. The rust formed on the outside is still permeable by the water and salt ions, which means that we would expect this rusting to happen underneath the top layer of rust as well. This should continue until the nail becomes completely iron oxide (rust). Let us know if this happens! For full details on the chemistry of nails rusting, check out csun.edu.

      Thanks for your question!

    1. Hi Rouzana! If you are able to have access to laboratory scales within a high school, you should be able to take a measurement of each nail mass before and after the experiment. The more sensitive the scales, the better!

    1. Hi! Here’s something that could start you off;
      – Aim; To determine which liquid produces the most rust on an iron nail.
      – Null Hypothesis; There will be no change in rust on an iron nail when immersed in ‘ABC liquid’.
      Have fun!

  2. I wanted to do a variation of this experiment for my high school class. Instead of weighing the change in mass to determine the amount of oxidation, I was wondering if there was a chemical that could dissolve only the nail(iron or any other metal) leaving the remaining iron oxide behind.

  3. hey
    can you tell us the chemical formula of the equation iron+water+oxygen= hydrated iron(III) oxide
    Should we cover the bottle of water to hasten the rusting process ?
    thank you

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