Storage Containers

Part of Petroleum and Tar

Storing petroleum and tar safely using materials that resist chemical attack, prevent leakage, and minimize fire risk.

Why This Matters

Petroleum and tar are among the most useful substances a rebuilding community can produce, but storing them improperly is genuinely dangerous. These materials dissolve many common containers, release flammable vapors, and can contaminate soil and water supplies if they leak. Ancient civilizations stored bitumen in ceramic vessels and animal skins for thousands of years, so effective storage does not require modern materials, but it does require understanding which materials resist petroleum and which ones fail.

Proper storage extends beyond just choosing the right container. Petroleum products range from volatile light fractions that evaporate quickly and produce explosive vapor concentrations, to thick tars that solidify when cold and must be reheated for use. Each fraction has different storage requirements. A community producing petroleum needs a systematic approach to containment, ventilation, and fire prevention.

The investment in proper storage infrastructure pays for itself many times over. Losing even a small quantity of hard-won petroleum to leakage, evaporation, or fire wastes days of labor. Building the right containers from the start is far easier than cleaning up a spill or rebuilding after a fire.

Container Material Selection

Materials That Work

Material	Best For	Advantages	Limitations
Fired stoneware	All petroleum products	Completely chemical-resistant, durable	Heavy, fragile if dropped
Metal (iron/steel)	Light fractions, bulk storage	Strong, sealable, reusable	Corrodes over time, requires smithing
Glass	Small quantities, light fractions	Transparent, inert	Fragile, hard to make in large sizes
Stone-lined pits	Bulk tar and heavy crude	Large capacity, simple	Not portable, risk of groundwater contamination
Tight-cooperage barrels	Heavy crude, tar	Large capacity, portable	Wood swells and may leak with light fractions

Materials That Fail

Do Not Use These

• Untreated wood — petroleum dissolves resins and weakens wood fiber; light fractions leak through grain
• Leather or rawhide — petroleum degrades animal proteins; containers become brittle and crack
• Woven baskets — even tar-coated baskets eventually fail as petroleum dissolves the coating
• Unfired clay — petroleum saturates unfired clay and weakens it to the point of collapse
• Natural rubber — petroleum dissolves natural rubber rapidly

Building Ceramic Storage Vessels

Fired stoneware is the ideal petroleum container for a low-technology community. It is completely chemical-resistant, can be made in any size, and lasts indefinitely.

Design Specifications

For petroleum storage, ceramics must meet higher standards than ordinary pottery:

1. Wall thickness — minimum 8-10 mm for vessels under 20 liters, 12-15 mm for larger vessels
2. Firing temperature — stoneware temperatures (1200-1300 C) produce vitrified, non-porous walls. Earthenware (below 1100 C) remains porous and will slowly seep
3. Narrow mouth — a small opening relative to body size reduces vapor escape and makes sealing easier
4. Flat base — ensures stable placement; rounded bottoms risk tipping
5. Lug handles — thick, well-attached handles for safe carrying

Lid and Seal Design

A tight seal is critical, especially for lighter petroleum fractions:

1. Flanged rim — throw a flat flange around the vessel mouth that a lid can sit on
2. Matching lid — throw a lid with a downward-facing lip that nests inside the flange
3. Clay luting — seal the joint with a strip of wet clay pressed around the lid-to-rim junction; this dries to form an airtight seal that can be broken and reapplied
4. Wax seal — for better sealing, pour beeswax around the lid joint after the clay lute dries

Size Standards

Standardize on 2-3 vessel sizes for your community. A 5-liter vessel for daily use, a 20-liter vessel for intermediate storage, and a large 50-liter vessel for bulk reserves. Consistent sizes simplify inventory and transport.

Marking and Identification

Scratch or paint clear markings on each vessel before firing:

• Contents — “CRUDE,” “TAR,” “LIGHT OIL,” etc.
• Date filled — scratch the date when the vessel is filled
• Hazard marking — a consistent symbol (such as a flame shape) that everyone in the community recognizes as flammable

Metal Containers

Where metalworking capability exists, metal containers offer several advantages over ceramics: they are lighter, nearly unbreakable, and can be sealed more tightly.

Sheet Metal Vessels

1. Material — wrought iron or mild steel sheet, 1-2 mm thick
2. Construction — form cylindrical bodies by bending sheet around a mandrel and riveting or forge-welding the seam
3. Bottom — rivet or weld a circular base plate; seal the seam with lead solder or clay luting
4. Lid — a friction-fit lid with a rolled edge that presses tightly into the vessel mouth
5. Handle — riveted bail handle for carrying

Seam Sealing

The critical challenge with metal containers is making seams petroleum-tight:

• Forge welding — the strongest option; requires skilled smithing
• Riveted and soldered — rivet for structural strength, then run lead-tin solder along the seam interior
• Riveted and tarred — coat interior seams with hot tar; effective for heavy crude but not for light fractions that dissolve tar
• Clay slip — coat interior seams with a thin layer of fire-clay slip, then gently heat to harden

Preventing Corrosion

Petroleum itself is mildly corrosive to iron, and any water content accelerates rusting:

• Interior coating — apply a thin layer of beeswax, tallow, or pine pitch to the interior surfaces
• Exterior coating — paint or tar-coat the exterior to prevent atmospheric corrosion
• Dry storage — keep metal containers off the ground on wooden racks to prevent moisture contact
• Inspection schedule — check metal containers monthly for rust spots; sand and re-coat as needed

Bulk Storage Solutions

For communities producing significant quantities of petroleum, individual vessels are impractical. Larger storage systems are needed.

Stone-Lined Pits

The simplest bulk storage is an excavated pit lined with stone:

1. Excavate — dig a pit 1-2 meters deep, sized for your storage needs
2. Line with stone — lay flat stones tightly against the pit walls and floor
3. Seal joints — fill gaps between stones with clay mortar
4. Apply clay plaster — coat the entire interior with a 3-5 cm layer of well-puddled clay, pressed firmly and smoothed
5. Cover — build a timber and earth roof over the pit, leaving a small access hatch
6. Drainage — ensure the pit floor slopes to one corner where a sump allows collection

Groundwater Protection

Never dig a storage pit where the water table is within 3 meters of the pit floor. Petroleum contamination of groundwater is nearly impossible to remediate with pre-industrial technology. Site pits on high ground, well away from wells and water sources.

Above-Ground Cisterns

For areas with high water tables or rocky ground:

1. Stone or brick walls — build circular walls 1-1.5 meters high using mortared stone or fired brick
2. Interior plaster — apply a thick clay plaster rendered with fine sand for a smooth, sealed surface
3. Roof — cover with a timber and thatch or tile roof to keep out rain and reduce sun exposure
4. Bund wall — build a low containment wall (30 cm) around the cistern to catch any overflow or leakage

Safety Systems

Fire Prevention

Every petroleum storage area must incorporate fire prevention measures:

1. Separation distance — maintain at least 15 meters between petroleum storage and any building, forge, kiln, or cooking fire
2. Earth bunding — surround storage areas with an earth berm at least 50 cm high to contain spills
3. Sand buckets — keep buckets of dry sand near all storage areas; sand smothers petroleum fires (water spreads them)
4. No-flame zone — post clear markers defining the no-flame perimeter; enforce this rigorously

Ventilation

Light petroleum fractions continuously release flammable vapors:

• Outdoor storage — always preferred; natural air movement disperses vapors
• Indoor storage — if unavoidable, ensure the building has low-level ventilation openings (vapors are heavier than air and pool at floor level)
• Never store in basements or pits — vapors accumulate in low areas and can reach explosive concentrations

Spill Response

Prepare for spills before they happen:

1. Sand and earth — keep piles of dry sand or earth near storage areas to absorb spills
2. Containment — bund walls and berms prevent spills from spreading
3. Cleanup — soak up spilled petroleum with sand, then collect and dispose of contaminated material by burning in a controlled fire pit (downwind, away from structures)
4. Never wash with water — water spreads petroleum and carries it into waterways

Transport Considerations

Moving petroleum between production and storage sites requires planning:

Carrying Containers

• Ceramic jugs (5-10 liters) with sealed lids for short distances on foot
• Paired containers on a carrying pole across the shoulders for balance
• Cart transport — pack containers in straw or sawdust to prevent breakage; secure against shifting
• Never transport in open containers — splashing wastes material and creates fire hazards

Inventory Management

A simple record-keeping system prevents waste and ensures supply:

• Label every container with contents, date, and source
• First in, first out — use oldest stock first to prevent degradation
• Monthly inventory — count and inspect all containers; note any losses to evaporation or leakage
• Segregate by type — store light fractions separately from heavy crude and tar, both for safety and for ease of access

Seasonal Considerations

Storage requirements change with temperature:

Season	Light Fractions	Heavy Crude	Tar
Summer	Higher vapor pressure; tighten seals, increase ventilation	Flows easily; good time to transfer between containers	Soft and workable; may flow out of open containers
Winter	Lower vapor risk but may gel	Thickens; may need warming to pour	Solidifies; store in vessels you can heat
Rainy season	Protect from water intrusion; check seals	Water contamination risk; keep covered	Unaffected if covered

Tar Storage Shortcut

Solidified tar can be stored without any container at all. Pour hot tar onto a flat stone slab in blocks or cakes. Once cool, stack the solid blocks under a simple roof. When needed, chip off pieces and re-melt. This is how pine tar was traditionally stored and transported across Northern Europe.