Axle Grease

Part of Petroleum and Tar

Making axle grease and lubricants from petroleum seeps, animal fat, and tar-based compounds.

Why This Matters

Friction is the silent destroyer of mechanical infrastructure. Every cart, wagon, watermill, lathe, windmill, and door hinge in a rebuilding community depends on lubrication to function efficiently and survive prolonged use. Without grease, wooden axles char and seize, metal bearings score and lock, and the mechanical advantage of wheels — humanity’s most fundamental labor-saving technology — is dramatically reduced.

In a world without petroleum refineries, axle grease must be manufactured from whatever materials are locally available: animal fats, plant oils, tar, pitch, and natural petroleum seeps. The good news is that effective lubricants were produced for thousands of years before the industrial age. Roman chariots, medieval mill gears, and colonial wagons all ran on hand-made grease formulations that are entirely reproducible with primitive technology.

Understanding lubrication chemistry also has cascading benefits. The same principles that keep an axle turning smoothly apply to leather conditioning, rust prevention, waterproofing, and tool maintenance. A community with reliable grease production has a significant advantage in maintaining all of its mechanical and metal assets.

Understanding Lubrication

What Grease Actually Does

Grease works by creating a thin film between two surfaces that would otherwise rub directly against each other. This film:

1. Reduces friction — less force needed to move parts
2. Prevents wear — surfaces do not contact directly
3. Dissipates heat — the lubricant carries heat away from the friction zone
4. Excludes contaminants — dirt and moisture cannot reach the bearing surface
5. Prevents corrosion — metal surfaces are sealed from air and moisture

Properties of Good Grease

Property	Why It Matters	Test Method
Viscosity (thickness)	Must stay in place but flow under pressure	Squeeze between fingers — should feel slippery, not watery
Adhesion	Must cling to surfaces	Apply to vertical surface — should not drip off quickly
Temperature stability	Must not melt in summer or harden in winter	Heat a sample — good grease stays soft over a wide range
Water resistance	Must not wash away in rain	Submerge a smear in water — should not disperse
Load capacity	Must not squeeze out under heavy weight	Test on loaded axle — listen for squealing

Grease Recipes from Available Materials

Recipe 1: Tallow Grease (Simplest)

The most basic grease, usable immediately with common materials.

Ingredients:

• Rendered animal fat (tallow from cattle/sheep, or lard from pigs)
• Optional: wood ash (very fine, sieved)

Method:

1. Render fat by slowly melting raw animal fat in a pot over low heat
2. Strain through cloth to remove crackling and tissue
3. Allow to cool to a thick paste consistency
4. For improved performance, mix in fine wood ash at 10-15% by volume while still warm
5. Stir thoroughly until uniform
6. Store in sealed containers — clay pots with lids, or wooden boxes

Performance: Adequate for low-speed, moderate-load applications. Needs reapplication frequently (every 50-100 km of travel for cart axles). Attracts insects and rodents if not protected.

Recipe 2: Tar Grease (Superior)

Combining tallow with tar or pitch creates a significantly better lubricant.

Ingredients:

• Rendered tallow or lard — 3 parts
• Pine tar or birch tar — 1 part (see Birch Tar)
• Beeswax — small amount (5-10% by volume) for consistency

Method:

1. Melt tallow over gentle heat
2. Add tar and stir until fully incorporated — the mixture will darken considerably
3. Add beeswax and continue stirring until melted and blended
4. Remove from heat and stir occasionally as it cools to prevent separation
5. The finished grease should be dark brown to black, smooth, and tacky

Performance: Excellent for wooden axles and slow-speed metal bearings. The tar provides water resistance and antimicrobial properties (insects avoid it). The beeswax adds body and temperature stability. Reapply every 200-300 km for cart axles.

Recipe 3: Petroleum-Based Grease

If you have access to natural petroleum seeps or oil springs.

Ingredients:

• Natural petroleum (crude oil, surface seep material)
• Tallow or lard — equal parts
• Lime powder (calcium hydroxide from slaked lime) — 10% by volume

Method:

1. Collect petroleum and allow heavy sediment to settle (see Collection Methods)
2. Warm the petroleum gently (outdoors — fumes are flammable and noxious)
3. Mix warm petroleum with melted tallow in equal proportions
4. Sprinkle in lime powder while stirring — this acts as a thickener
5. Stir continuously as the mixture cools
6. The lime reacts with fatty acids to form calcium soap, which thickens the grease

Performance: The closest thing to modern grease achievable without industrial chemistry. Excellent adhesion, water resistance, and load capacity. Suitable for metal-on-metal bearings.

Fire Safety with Petroleum

Natural petroleum is flammable. Never heat it over an open flame. Use a water bath (double-boiler method) or work well away from fire sources. Work outdoors for ventilation.

Recipe 4: Plant Oil Grease

For regions without animal fat or petroleum.

Ingredients:

• Plant oil (castor, rapeseed, olive, sunflower — castor is best for lubrication)
• Beeswax — 20-30% by volume
• Fine calcium powder (crusite lime, chalk dust, or diatomaceous earth) — 10%

Method:

1. Heat plant oil gently
2. Melt beeswax into the oil, stirring constantly
3. Add calcium powder and stir until uniform
4. Pour into containers and allow to set
5. The result is a soft paste that performs comparably to tallow grease

Application Methods

Wooden Axle Lubrication

Wooden axles in wooden hubs (the most common early wheel configuration):

1. Remove the wheel — lift the cart with a lever and support it
2. Clean the axle — scrape off old grease, dirt, and debris with a stick or cloth
3. Inspect for wear — look for flat spots, scoring, or charring on the axle surface
4. Apply fresh grease — pack a generous layer around the entire axle surface, especially the bottom (load-bearing) surface
5. Also grease the inside of the hub — where the hub contacts the axle
6. Replace the wheel and rotate it by hand — it should turn freely with minimal resistance
7. Wipe excess from outside the hub to prevent dirt accumulation

Metal Bearing Lubrication

For metal journal bearings, gudgeons, and pivots:

1. Clean the bearing with a cloth dampened in hot water or dilute lye
2. Apply grease with a stick or brush, packing it into all contact surfaces
3. For enclosed bearings, fill any grease cups or channels
4. Rotate the shaft by hand to distribute grease evenly
5. Wipe away any excess that squeezes out

Gear and Mechanism Lubrication

For mill gears, lathe mechanisms, and similar machinery:

1. Apply grease to gear teeth where they mesh
2. Run the mechanism slowly by hand to distribute
3. Heavier grease (tar-based) works better on gears than lighter tallow grease
4. Reapply when gears begin to squeal or run rough

Maintenance Schedule

Application	Regreasing Interval	Signs of Needed Regreasing
Cart/wagon axles	Every 100-300 km	Squealing, heat at the hub, resistance to turning
Watermill bearings	Weekly during operation	Grinding noise, excessive heat, vibration
Door hinges	Monthly	Squeaking, stiffness
Lathe bearings	Before each use session	Rough running, visible dryness
Windmill bearings	Weekly during use	Same as watermill
Plow coulter/share	Before each use	Increased draft force required

Storing Grease

• Container: Sealed clay pots, wooden boxes with tight lids, or leather pouches
• Temperature: Store in a cool, dark place — heat causes separation
• Shelf life: Tar-based grease keeps for years. Pure tallow grease may go rancid after 6-12 months, but rancid grease still lubricates adequately
• Travel supply: Carry a sealed pot of grease on every cart or wagon — roadside regreasing is a normal part of long-distance travel
• Quantity: A cart making regular trips needs approximately 1 kg of grease per month

Troubleshooting

Problem	Cause	Solution
Grease melts and drips off in hot weather	Too much liquid fat, not enough binder	Add more beeswax or lime thickener
Grease too hard to apply in cold weather	Wax or tar content too high	Warm the grease before applying; adjust recipe with more fat
Axle still squeals after greasing	Insufficient application or worn bearing surface	Apply more grease; inspect axle for damage and repair
Grease attracts ants/vermin	Pure tallow without tar	Add tar or bitter plant extract; keep storage containers sealed
Metal bearing corroding despite grease	Water penetrating grease film	Switch to tar-based recipe with better water resistance
Grease separating in storage	Ingredients not properly blended	Re-melt and stir thoroughly; add small amount of beeswax

Axle grease is one of those humble necessities that makes the difference between a functional mechanical infrastructure and one that grinds itself to pieces. With a reliable supply of animal fat or plant oil, combined with tar or petroleum when available, any community can keep its wheels turning, its mills grinding, and its mechanical systems operating smoothly for years.