5 Steps to Repair a Ship Launching Airbag


Ship launching airbag is also known as an inflatable marine airbag, roller bag, empty bag, or life bag. It is a long, cylindrical balloon-shaped device made of heavy-duty synthetic rubber, with inner and outer rubber layers. They are widely used in ship launching and landing, heavy lifting and transport, wreck salvage and stranded ship rescue. These marine launching airbags are robust. They usually last up to 15 years with reasonable maintenance. However, they are inevitably subject to puncture by some neglected sharp object. In such cases, it becomes vital to repair marine airbags correctly. Good maintenance restores the airbag’s full performance. It also extends its life. Next, this article will cover the 5 Steps to Repair a Ship Launching Airbag. It will also explain the importance of preparing the required tools and materials prior to repair.

Table of Contents

Repair tool

Angle grinder: used to sand cuts on airbags to ensure a smooth surface.

Brush: used to apply and clean the rubber when repairing and cutting on the boat launching airbag.

Hydraulic jacks: The tool presses down on the rubber sheet. It also heats the heating plate, to ensure even pressure during the repair process.

Steel plate and block: It is used for hydraulic jacking. This presses the rubber block tightly against the heating plate. At the same time, steel plates are placed on the heating plate to provide additional support.

Brackets: The hydraulic jack presses against the heating plate with the rubber sheet. This provides additional support.

Large Needle with String: Used to stitch the incision through the string to ensure a secure repair.

Sandbags: Sandbags are placed between the marine airbag and the supports. This provides additional pressure and stability.

Heating Plates: Heating pads are used to vulcanise incisions. They also promote the adhesion and strength of the repair material.

5 Steps to Repair a Ship Launching Airbag

Repair material

Facing Adhesive: used to repair incisions and damaged areas to ensure sealing and durability.

Cordage film: provides additional strength and support and is used to reinforce the repair area.

Glue Adhesive: Used to bond different materials to ensure a strong repair area.

Isolation Cloth: Used to isolate the repair area and ensure even distribution of the repair material and glue.

Restoration Steps

1. Clean the airbag surface

When preparing an airbag for repair, first clean the surface of the airbag to make sure there is no sand or oil. Allow the airbag to dry and place it in a clean area. Make sure the airbag is not submerged in water for more than 10 minutes before repair.

2.Inspect and mark the damaged area

Mark the area of the airbag to be repaired by extending it from the centre to the outside (20-26cm). Make sure that hidden areas of damage are not overlooked. The size of the extension depends on the size of the damaged area.

3. Repair

  1. Wear the surface of the damaged area until the cord is exposed, but do not damage the cord layer.
  2. For longer cracks, use a large needle with a string to stitch. Keep the needle approximately 2-3 cm from the crack and the stitches approximately 10 cm apart.
  3. Clean the surface of the repair area with petrol and allow to dry.
  4. On the repair area, brush on the special glue. This glue consists of raw rubber material mixed with petrol in a 1:8 ratio. Leave the glue to dry again.
  5. Prepare the repair rubber material, making sure it is the same as the airbag. Seal the leaking area with a 1mm thick pure rubber band. The rubber band should be more than 1cm wider and longer than the crack.
  6. Place layers over the damaged area, including interleaved and offset layers. Interleaving should have rounded corners with a radius of 40-50mm.

4.Hot vulcanisation process

Vulcanise the damaged area using a simple working structure. The temperature is controlled at 150 ± 5 degrees. Pressure is applied using a jackhammer. Then close the hot steel plate and allow it to cool slowly to 60 degrees. During this time, do not remove the jacket.

5. Inspection

Inspect the repair area to make sure there are no leaks. Finally, inflate and pressure test.

Ship launching with marine airbags

Maintenance of ship launching airbag

Strictly control the pneumatic pressure: Make sure the pneumatic pressure does not exceed the upper limit of the working pressure when in use. This prevents excessive pressure from damaging the airbag.

Avoid sharp objects: During use, avoid contact between the airbag and sharp objects, such as steel nails and welding slag. This could damage the airbag’s surface.

Careful transport: When transporting, make sure the airbag rolls or moves under natural conditions. Never drag it on the ground to prevent friction and wear.

Long-term storage and maintenance: when not in use for a long time, the ship launching airbag should be maintained. Clean the surface of the airbag. Cover and fill it with talcum powder. Place it in a dry, cool, ventilated place away from fire sources.

Regular Inspection: Regularly check the appearance and airtightness of the airbag. Ensure there is no obvious damage or leakage. If problems are found, repair or replace the damaged part in time.

The above are the basic maintenance and care methods for ship launching airbags. If you have any questions about these steps or need further help, please feel free to contact us. Jerryborg is a professional marine equipment supplier. We are committed to providing customers with high-quality marine fenders and other products. We can also provide customized solutions based on customer needs.


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