Hoses and Tubing

Part of Rubber and Polymers

Making rubber hoses and tubing for water, air, and fluid transfer.

Why This Matters

Rigid pipes made from wood, clay, metal, or stone can carry water from point A to point B, but they cannot bend, flex, or absorb vibration. The moment you need to connect a pump to a pipe, route fluid around an obstacle, attach a nozzle to a water source, or handle any moving connection, you need flexible tubing. Rubber hoses solve problems that rigid pipes simply cannot.

In a rebuilding civilization, hoses are critical for water distribution from hand pumps, irrigation delivery, bellows connections for forges and furnaces, pneumatic tools, hydraulic systems, siphoning, and medical applications like fluid delivery and wound irrigation. Even a simple garden hose — something we take entirely for granted — represents a sophisticated manufacturing challenge: a tube that must be flexible enough to bend around corners, strong enough to withstand internal pressure, and durable enough to last through seasons of use.

Making rubber hoses from scratch requires combining several skills: rubber processing, textile weaving (for reinforcement), and vulcanization. The result, however, is one of the most useful products a community can manufacture. A single well-made rubber hose can serve for years and enable dozens of applications that would otherwise require awkward workarounds with rigid materials.

Hose Construction Types

Type 1: Simple Dipped Tube

The easiest to make but limited in pressure and durability:

• A tube made purely from rubber, with no reinforcement
• Suitable for: low-pressure drainage, siphoning, gravity-fed water flow
• Pressure limit: approximately 0.5-1 bar (7-15 psi)
• Best for: small diameters (under 15 mm)

Type 2: Fabric-Reinforced Hose

The most practical general-purpose hose:

• A rubber tube with one or more layers of woven fabric embedded in the wall
• Suitable for: moderate-pressure water, air delivery, pump connections
• Pressure limit: 3-10 bar (45-150 psi) depending on reinforcement
• Best for: medium diameters (10-50 mm)

Type 3: Wire-Reinforced Hose

For high-pressure and suction applications:

• A rubber tube with embedded wire helix or wire braid
• Suitable for: high-pressure hydraulics, suction (vacuum) applications
• Pressure limit: 10-30+ bar (150-450 psi)
• Also resists collapse under vacuum (suction hoses)

Making a Simple Dipped Tube

Materials Needed

• Processed, cleaned natural rubber
• A mandrel (a smooth rod around which the tube is formed)
• Turpentine or other solvent (for making rubber cement)
• Talc, chalk powder, or cornstarch (as release agent)

Process

1. Prepare a mandrel — a smooth wooden or metal rod of the desired inner tube diameter. Sand it perfectly smooth — any surface imperfection transfers to the tube interior
2. Coat the mandrel with talc or chalk powder so the finished tube can be removed
3. Make rubber cement:
   • Cut raw rubber into thin shavings
   • Dissolve in turpentine (approximately 1 part rubber to 3-4 parts turpentine by volume)
   • Stir daily for 3-7 days until the rubber is fully dissolved
   • The result should be the consistency of thick paint
4. Dip the mandrel in rubber cement, coating it evenly
5. Hang vertically and let the solvent evaporate (2-4 hours in warm, ventilated area)
6. Repeat — apply 10-20 coats, allowing each to dry between applications
7. Build up wall thickness — each coat adds approximately 0.3-0.5 mm
8. Final drying — let the last coat cure for 24 hours
9. Remove from mandrel — dust the end with talc, work it loose, and roll the tube off

Mandrel Selection

For curved hoses, use a flexible mandrel (thick wire or rope). For straight tubes, use rigid wooden dowels. For very long tubes, use bamboo. The mandrel must be slightly tapered or separable to allow tube removal.

Alternative: Wrap Method

If you do not have solvent for rubber cement:

1. Roll raw rubber into very thin sheets (under 1 mm)
2. Coat the mandrel with talc
3. Wrap rubber sheets around the mandrel, slightly overlapping each wrap
4. Continue wrapping to build desired wall thickness
5. Smooth the outer surface by rolling between flat boards
6. Vulcanize the wrapped assembly (see below)
7. The heat fuses the overlapping layers into a solid tube wall

Making Fabric-Reinforced Hose

This produces a far superior hose — stronger, more durable, and capable of withstanding significant pressure.

Materials

• Processed rubber (sheets and/or cement)
• Woven fabric — cotton, linen, or hemp cloth (tightly woven)
• Mandrel
• Vulcanization materials (sulfur)

Construction Steps

Step 1: Inner Liner

Apply a thin layer of rubber to the mandrel:

• 2-3 coats of rubber cement, or
• A single thin rubber sheet wrapped tightly
• This becomes the inner lining that contacts the fluid

Step 2: First Fabric Layer

1. Cut fabric into strips slightly wider than the hose circumference
2. Coat one side of the fabric with rubber cement (or place a thin rubber sheet on it)
3. Wrap the coated fabric around the rubber-lined mandrel
4. Overlap the edges by about 10 mm
5. Smooth and press firmly to eliminate air bubbles

Step 3: Intermediate Rubber Layer

Apply another thin rubber layer over the fabric:

• 1-2 coats of rubber cement, or
• A thin rubber sheet wrapped over the fabric
• This bonds the first fabric layer to the next

Step 4: Second Fabric Layer (Optional for Higher Pressure)

Repeat Step 2, orienting the fabric at an angle to the first layer:

• If the first layer’s weave runs along the hose length, angle the second layer at 45 degrees
• This cross-ply arrangement dramatically increases burst pressure

Step 5: Outer Cover

Apply a final rubber layer over the outermost fabric:

• 3-5 coats of rubber cement for a smooth finish
• This outer cover protects the fabric from abrasion, moisture, and UV degradation

Step 6: Vulcanization

The entire assembly must be vulcanized to create a bonded, unified structure:

1. Mix the rubber (before assembly) with 5-8% sulfur
2. Wrap the finished hose assembly tightly with cloth tape or strips of cotton to maintain pressure during curing
3. Heat to 140-150°C for 45-60 minutes using one of these methods:
   • Immerse in hot oil bath
   • Place in steam chamber
   • Wrap with heated sand
4. Allow to cool before unwrapping
5. Remove the mandrel by twisting and pulling (the talc coating prevents bonding)

Step 7: Testing

Before putting any hose into service:

1. Plug one end securely
2. Fill with water
3. Apply pressure (a hand pump works well)
4. Check for leaks along the entire length, especially at the fabric overlap seams
5. A properly made hose should hold 3-5 times its intended working pressure without failure

Wire-Reinforced Suction Hose

Ordinary hoses collapse under vacuum (suction). To prevent this, embed a wire helix:

Process

1. Form the inner liner and first rubber layer as above
2. Wind wire in a helix around the rubber tube:
   • Use iron or copper wire, 1-2 mm diameter
   • Wind at a pitch of 10-15 mm (distance between coils)
   • The wire helix resists collapse under vacuum
3. Apply rubber over the wire to embed it
4. Add fabric reinforcement over the rubber
5. Apply outer cover
6. Vulcanize the complete assembly

Wire Helix Forming

To wind wire evenly:

1. Mark the mandrel with spiral guidelines (wrap a string at the desired pitch and trace alongside it)
2. Wind wire following the guidelines, keeping tension even
3. Tack the wire in place with spots of rubber cement at several points
4. The wire must not overlap or cross itself

Hose Fittings and Connections

A hose is useless without reliable end connections.

Barb Fitting

The simplest and most common:

1. Make a barb — a tapered metal or hardwood connector with one or more ridges (barbs) along its length
2. Soften the hose end in hot water
3. Push the barb into the hose — the barbs grip the inner wall
4. Secure with a clamp:
   • Wire wrap: wind iron wire tightly around the hose over the barb, twisting to tighten
   • Hose clamp: a strip of sheet metal with a tightening mechanism
   • Cord binding: wrap tightly with waxed cord and tie securely

Ferrule Fitting

For higher pressure:

1. Slide a metal sleeve (ferrule) over the hose end before inserting the barb
2. Insert the barb
3. Crimp or hammer the ferrule — compressing it squeezes the hose onto the barb
4. This creates a permanent, high-pressure connection

Hose-to-Pipe Adapters

To connect a flexible hose to a rigid pipe:

1. Taper the pipe end slightly
2. Slip the hose over the pipe
3. Secure with wire clamp or ferrule
4. For a more permanent joint, apply rubber cement to the pipe before assembly

Sizing Guide

Application	Inner Diameter	Wall Thickness	Reinforcement	Working Pressure
Siphon tube	6-10 mm	2-3 mm	None needed	Gravity only
Garden watering	12-20 mm	3-5 mm	1 fabric layer	2-4 bar
Pump delivery	20-30 mm	4-6 mm	2 fabric layers	4-8 bar
Bellows connection	25-50 mm	3-4 mm	1 fabric layer	0.5-1 bar
Suction hose	25-50 mm	5-8 mm	Wire helix + fabric	Vacuum rated
Hydraulic line	8-15 mm	5-8 mm	Wire braid + 2 fabric	10-30 bar

Maintenance and Repair

Extending Hose Life

• Store out of sunlight — UV radiation degrades rubber rapidly
• Drain after use — standing water promotes internal mold and degradation
• Avoid kinking — sharp bends stress the reinforcement and create weak points
• Keep clean — dirt on the surface acts as an abrasive when the hose is dragged
• Coil loosely — tight coiling creates memory bends and stress points

Repairing Leaks

Pinhole leaks:

1. Dry the area around the leak
2. Roughen with coarse sandstone
3. Apply a patch of raw rubber (with sulfur mixed in) over the hole
4. Wrap tightly with cloth
5. Vulcanize by applying heat (wrap with hot, wet cloths for 30 minutes at minimum)

Burst sections:

1. Cut out the damaged section cleanly
2. Insert a rigid tube (bamboo, metal, or hardwood) as a splint, extending 5 cm into each cut end
3. Secure both ends with wire clamps
4. Apply rubber cement and wrap the joint with rubber-coated fabric
5. Vulcanize if possible

End fitting leaks:

1. Remove the old fitting
2. Cut back the hose to fresh material
3. Re-install with a new barb and tighter clamp
4. If the hose end is swollen or degraded, trim until you reach sound material