Understanding Rust: What It Is and How to Prevent It

Whether you're forging a functional blade or a decorative piece, there's one universal enemy to all metalwork: rust. Every blacksmith eventually confronts it — that flaky orange-brown coating that can undo hours of hard work. But rust isn't just an annoyance; it’s chemistry. Let’s break down how it forms and how I personally combat it in my forge.

What Is Rust, Exactly?

Rust is the common name for iron oxide, a compound that forms when iron, oxygen, and water (or even just moisture in the air) interact. The basic reaction looks like this:

Iron (Fe) + Water (H₂O) + Oxygen (O₂) → Iron Oxide (Fe₂O₃)

Rust eats away at metal over time, weakening its structure. Unlike patina on bronze or copper, rust is not protective — it spreads and deteriorates.

Conditions That Cause Rust to Form Faster

• Humidity: Even ambient moisture can trigger rust.

• Salt Air: Coastal environments are brutal on steel.

• Acidic Exposure: Chemicals, sweat, and even wood tannins can accelerate corrosion.

• Poor Finishing: Raw, unsealed metal is an open invitation for oxidation.

How I Prevent Rust in My Blacksmith Work

Here’s what I do — both during and after forging — to keep rust at bay:

1. Choose the Right Metal

While plain carbon steel is beautiful and affordable, it’s also more rust-prone. For some projects, I use:

• Stainless steel for low-maintenance items.

• Galvanized or coated stock (only cold-worked, never forged — due to toxic fumes).

• Bronze or copper alloys, which age gracefully and resist corrosion.

2. Surface Prep Matters

After forging:

• wire brush, grind, or sandblast the surface to remove scale.

• I avoid leaving deep pits or sharp crevices where moisture can collect.

• Sometimes I apply a light etch for texture, then seal it immediately.

3. Protective Finishes I Use

I use different finishes depending on the piece’s purpose:

• Oil & Wax Finish
  A classic blacksmith’s method — I apply hot beeswax, boiled linseed oil, or a mix while the piece is still warm. This forms a barrier that repels moisture and gives a rich finish.

• Paint or Clear Coat
  For outdoor items, I may use a rust-resistant primer followed by durable paint or a clear enamel spray.

• Bluing or Browning (Controlled Oxidation)
  Sometimes I pre-oxidize a surface and then seal it to create a stable finish that resists further corrosion.

• Powder Coating (for collaborations or modern pieces)
  It’s not traditional, but it's incredibly effective for heavy-use or outdoor products.

4. Post-Sale Care Instructions

I always educate customers:

• Reapply wax or oil once or twice a year (or more often for high-use items).

• Avoid prolonged contact with water, chemicals, or soil.

• Store tools in a dry place, and wipe them down after use.

A Note on Patina vs. Rust

Some clients confuse rust with patina — the dark, oxidized surface that forms naturally on iron over time. Patina can be desirable and even protective. Rust, on the other hand, is active decay.

The trick is knowing when to let nature enhance your work — and when to fight it.

In Summary

Rust is inevitable if metal is left unprotected — but it’s preventable with the right materials, prep, finishes, and maintenance. As a blacksmith, I respect the elements, but I also work to preserve the integrity and appearance of every piece I make.

Have a hand-forged item showing signs of rust? Drop me a message — I’d be happy to help you restore and protect it.

If you would like to discuss a potential project, please do not hesitate to contact us.