Preventing Corrosion on bare metal

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Preventing Corrosion on bare metal
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Driving Question

• I left an old iron cylinder out on the
  workbench one night. Why did it get rusty?

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Investigation Questions

• Can iron be treated to prevent rust?
• What treatments work best?

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Prior Research

• Rust is the common term for iron oxide
• Also known as Fe2O3
• So common there is little pure iron in nature.
• Occurs as the result of a chemical reaction
  between oxygen and iron called corrosion
• Requires water as an electrolyte.

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Process

• First, water comes in contact with iron or steel
• Then, the water combines with carbon dioxide and
  forms an acid that dissolves some of the metal
• The water also breaks down into hydrogen and
  oxygen
• The free oxygen then combines with the dissolved
  iron to form rust

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Hypothesis

• More rust will form on the untreated iron than
  the treated iron because the treatments will keep
  water from getting to the metal.
• Best to worst

• Dura-lube
• WD-40
• Engine Oil

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Procedure

• Prepare Samples
• cut from same bar
• grind off existing rust
• Coat with equal amounts of product
• Prepare controlled environment
• same size bags
• Same amount, kind of water
• Regulate temperature

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Procedure

• Observe and record
• Surface area covered by rust.
• Color of the water in the bag.

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Variables

• Controlled variables for this experiment include
• The composition of the samples.
• The physical size of each sample.
• The rust content of the samples.
• The amount of coating used.
• The size of the plastic bags.
• The amount of water in each bag.
• The composition of the water.
• The temperature of the samples.

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Variables

• Manipulated variable The coating or lack of
  coating for the iron bar sample
• Responding variables
• The amount of rust observed on the top surface
  of each sample.
• The amount of rust coloring the water in each
  bag.

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Samples before water added
Sample 1 (No coating)
Sample 2 (WD-40)
Sample 3 (Oil)
Sample 4 (Dura-lube)
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Sample 1 Before and after
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Sample 2 Before and after
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Sample 3 Before and after
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Sample 4 Before and after
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Comparison of surface area rusted
Sample 1 (No coating)
Sample 2 (WD-40)
Sample 3 (Oil)
Sample 4 (Dura-lube)
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Comparison of surface area rusted
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Conclusions

• Untreated iron rusts more and faster than iron
  coated with a corrosion inhibitor.
• Oil worst of all the products.
• WD-40 and Dura lube hard to determine.

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Color Chart
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Water color graph
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Conclusion

• My first hypothesis was correct, my second
  incorrect.
• WD-40 best.
• Dura-lube second best.
• Engine oil worst.
• Even the worst coating is better than no coating
  at all.

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Because