A very simple rust-protective paint can be made with only a few ingredients. The idea is to create a water-repelling barrier containing rust-inhibiting pigment.

Simple DIY Rust Paint (Traditional Style)

Ingredients

• Boiled linseed oil – binder that hardens into a protective film
• Iron oxide pigment (red oxide powder) – corrosion-resistant pigment
• Turpentine or white spirit – thins the mixture so it brushes well
• Optional: a little graphite powder – improves water resistance

Typical ratio:

• 2 parts boiled linseed oil
• 1 part turpentine / white spirit
• 1 part red oxide pigment

Method

1. Pour the boiled linseed oil into a jar or tin.
2. Add the red oxide pigment slowly while stirring.
3. Add turpentine or white spirit until the mixture has the thickness of normal paint.
4. Stir thoroughly until all pigment lumps disappear.
5. Let the mixture sit for 10–15 minutes so air bubbles escape.

Application

1. Wire-brush loose rust from the metal.
2. Brush on a thin coat of the paint.
3. Allow 24–48 hours to dry.
4. Apply a second coat for better protection.

The linseed oil cures by oxidation, forming a flexible waterproof film.

Why It Works

• Iron oxide pigment is chemically stable and slows corrosion.
• Linseed oil seals the surface from oxygen and moisture.
• Solvent lets the oil penetrate rust pores.

This type of coating is similar to old railway and farm machinery paints used for over a century.

Optional Improvement (Better Rust Protection)

Add a small amount of zinc oxide powder (about 10% of the pigment).
Zinc compounds help inhibit corrosion chemically.

A classic 19th-century rust-protective paint used on bridges, ships, and agricultural machinery was based on red lead pigment in oil. It worked extremely well because the lead compound chemically inhibited corrosion as well as sealing the metal.

⚠️ Important: red lead is toxic, so this is mainly of historical interest today.

Traditional “Red Lead” Rust Paint (Victorian Formula)

Ingredients

• Red lead pigment (lead tetroxide)
• Boiled linseed oil
• Turpentine

Typical proportions used by engineers:

• 4 parts red lead pigment
• 1 part boiled linseed oil
• Small amount of turpentine to thin

Method

1. Place the red lead powder in a mixing container.
2. Slowly add boiled linseed oil while grinding or stirring.
3. Continue mixing until a smooth paste forms.
4. Add a little turpentine to achieve brushable consistency.

Traditionally the mixture was ground using a paint muller on a stone slab to disperse the pigment properly.

Application

1. Remove loose rust with a wire brush.
2. Apply a thin first coat and allow to dry.
3. Apply a second coat for a full seal.
4. Often a topcoat of coloured oil paint was added.

This system protected iron structures for decades.

Why It Worked So Well

Red lead had two important properties:

1. Chemical corrosion inhibition

• It reacts with iron to form protective compounds.

2. Excellent barrier

• The pigment particles pack tightly in the oil film.

Together they formed one of the best rust primers ever used before modern coatings.

Modern Equivalent (Much Safer)

Today red lead has largely been replaced by pigments such as:

• Zinc phosphate
• Zinc oxide
• Micaceous iron oxide

These give similar corrosion protection without the lead toxicity.

💡 An interesting historical fact:
Parts of structures like the Forth Bridge survived over a century partly because of heavy red-lead paint systems applied during construction.

Radio amateurs and tower engineers often use a very durable protective coating based on bitumen (asphalt). It is simple, inexpensive, and extremely effective at excluding moisture.

This type of coating is commonly used on antenna towers, fence posts, and underground steel.

Simple Bitumen Rust-Proof Paint

Ingredients

• Bitumen / asphalt (roofing bitumen or bituminous paint)
• White spirit or kerosene (to thin)
• Optional: aluminium powder

Typical proportions:

• 3 parts bitumen
• 1 part white spirit
• Optional: a small amount of aluminium powder for UV resistance

Method

1. Place the bitumen in a metal container.
2. Slowly add white spirit while stirring until it becomes brushable.
3. If desired, mix in a small amount of aluminium powder.

The aluminium flakes help reflect sunlight and slow degradation.

Application

1. Remove loose rust and dirt.
2. Brush on a thick coat.
3. Allow several hours to dry.
4. Apply a second coat for long-term protection.

The coating dries into a flexible waterproof barrier.

Why It Works

Bitumen protects metal by:

• Completely blocking water and oxygen
• Remaining flexible, so it does not crack
• Self-sealing small scratches

For structures like antenna towers and buried steel, the goal is total moisture exclusion, which bitumen does very well.

Another Tower Trick (Very Common)

Many antenna installers also use:

• Cold galvanizing compound (zinc-rich paint)

These paints contain very high zinc content, which provides sacrificial protection—the zinc corrodes instead of the steel.

💡 A surprising technique sometimes used for antenna masts:
After painting, joints and bolts are coated with thick marine grease to prevent water ingress.