# Acid Rust Removal (DD-407)

> Rust is iron oxide. Acids, from mild citric or phosphoric acid to strong hydrochloric (muriatic) acid, react with it and dissolve it, leaving bare metal; in industry this is called pickling. Because bare steel rusts quickly and leftover acid keeps attacking it, the part is neutralized with a base such as baking soda, rinsed and dried or coated. The footage shows rusty parts cleaned in acid.

- Department: Science
- First published: 2024-12-03
- Last updated: 2024-12-03
- Permalink: https://detailenjoyer.com/case/acid-rust-removal/
- Author: Marcus Easterling (DetailEnjoyer), The Detail Department

## Quick facts

- **DD-407-F01**: Iron oxide. _(Write-up · Exhibit A (Rust))_
- **DD-407-F02**: Citric to hydrochloric. _(Write-up · Exhibit B (Acids))_

## Write-up

Acids dissolve rust and leave bare metal behind. Afterward the metal must be neutralized and rinsed.

1. **Rust**: Iron oxide.
2. **Acids**: Citric to hydrochloric.
3. **Pickling**: Industrial term.
4. **Neutralize**: Baking soda.
5. **Rinse**: Prevents flash rust.

## Related case files

- [Laser Rust Removal (DD-447)](https://detailenjoyer.com/case/laser-rust-removal/): I linked another way to remove rust

## Reel vs. record

- **Note**: The Reel calls the process acid etching; dissolving rust this way is usually called pickling, and etching refers to attacking the metal itself.

## Video: Acid Rust Removal: Acids Dissolve Rust and Leave Bare Metal Behind

- Duration: 24.3 s · Published: 2024-12-03
- File: https://detailenjoyer.com/assets/videos/DDJMVf3OLjC.mp4

### Transcript

Did you know? Acid, particularly weak acids like citric acid or stronger ones like hydrochloric acid, also known as muriatic acid, are commonly used for rust removal. The acid reacts with the rust, iron oxide, and dissolves it, leaving behind the clean metal surface. This process is known as acid etching. However, after using acid, it's important to neutralize the surface with a base, like baking soda, and thoroughly rinse to prevent further corrosion. NOW YOU KNOW!

## Questions & answers

**Q: What is rust?**  
A: Oxidized iron. _(Source: Write-up · Exhibit A (Rust) · Wikipedia: Rust)_

**Q: Another name for hydrochloric acid?**  
A: Hardware stores. _(Source: Write-up · Exhibit B (Acids) · Wikipedia: Rust)_

**Q: What neutralizes acid?**  
A: Base. _(Source: Write-up · Exhibit C (Pickling) · Wikipedia: Pickling (metal))_

**Q: Industrial term?**  
A: Metal finishing. _(Source: Write-up · Exhibit D (Neutralize) · Wikipedia: Rust)_

**Q: Why rinse?**  
A: Flash rust. _(Source: Write-up · Exhibit E (Rinse) · Wikipedia: Rust)_

## Sources

- [Wikipedia: Rust](https://en.wikipedia.org/wiki/Rust)
- [Wikipedia: Pickling (metal)](https://en.wikipedia.org/wiki/Pickling_(metal))

## Cite this case file

Easterling, Marcus. "Acid Rust Removal." The Detail Department (DetailEnjoyer), case file DD-407, last updated Dec 3, 2024. https://detailenjoyer.com/case/acid-rust-removal/