Contact us 02380812921 01614571215 02031026840

Surface Preparation and Coatings Removal

Overview

Using ultra high pressure water jets to clean or prepare surfaces is known as “hydroblasting”.

This is the process in which ultra high pressure jets are used to remove paint, rust, bitumen, epoxies and other coatings from almost any surface. The process does not cause damage to the underlying facade or generate any heat or dust. Hydroblasting also creates a perfectly clean (free from chemicals and non-visual contamination) surface on which new coatings can be applied.

In many cases this offers a cheaper, safer and more cost-effective alternative to dry abrasive blast cleaning or mechanical surface preparation methods.



Need a Coatings Removal & Surface Preparation quotation?

Briefing guide

Fill out our enquiry form to get a quotation.

Make an Enquiry Now

The RGL “Limpet” Crawler is an innovative UHP remote control system offering surface preparation with built in vacuum recovery capability.

RGL’s Limpet Crawler system remotely delivers UHP water to remove coatings and corrosion under a ‘high’ vacuum seal. Here are some things you need-to-know about the system and how it works:

  • Remote controlled via ‘fly by wire’ umbilical line to ground based operator/control pedestal.
  • In-built vacuum blast head which enables the system to be self-propelled and crawl vertically to 30 metres.
  • Copes with rivets and lapped plates with 15-20m step.
  • High vacuum blast head also provides a controlled method of waste water, management of contaminants and removal of water.
  • Ultra high pressure water delivered via portable, diesel-driven units with working pressure up to 3000 bar.
  • Integrated vacuum head and waste filtration system.
  • Three person crew allocated per Limpet.
  • Winch system provides safety net in the event of vacuum failure. The system also deploys the Limpet to high levels quickly and safely.
  • In-house system that has been developed and refined over the past ten years.

Areas not suitable for the Limpet crawler system (e.g. brackets and vertical pipes) are manually cleaned/prepared via a handheld water jetting lance. However, this typically involves less than 0.5% of the total surface area.

Hydroblasting is typically used on concrete structures such as bridges, but this method of surface preparation is transferable across much of a countries infrastructure. On concrete surfaces the Limpet is used for concrete surface preparation of bridge decks & tunnels, etc. and providing a clean dust free finish and without creating micro cracks, which can be caused by mechanical preparation methods.

This finish is perfect for laying new concrete, or coatings (such as waterproofing) as all chemical traces and debris are removed as part of the process.

Technical advantages

  • UHP water blasting provides a surface free from non-visible contamination.
  • Produces a perfect surface on which to apply new coating or additional concrete.

Safety and environmental advantages

  • RGL’s Limpet Crawler system is remote controlled and takes crews away from the work face, thus reducing working hazards.
  • Hydroblasting is dust-free – operatives rarely need to wear RPE (respiratory protective equipment) or work in sheeted, confined spaces.

Typical applications

  • Road, rail bridges and tunnels.

Compared to abrasive blast cleaning

  • The abrasives and contaminants from blast cleaning fall to the ground (or are wind dispersed) and have to be recovered and waste managed.
  • For every one ton of waste produced by hydroblasting, 200 tons of waste is produced by abrasive blast cleaning.

This is typically used on steel structures such as bulk storage tanks, bridges and large marine structures such as ships that require ongoing surface maintenance. It can also be selectively used to clean welded seams prior to inspection of steel tanks prior to hydro test.

The Limpet Crawler clings to steel structures by a powerful vacuum. It can be controlled remotely to cover the whole surface more quickly and efficiently than operatives with handheld lances, and without the need for scaffolding.

The vacuum used to secure the Limpet also removes all the water, dust and debris via a filtration system. This leaves the tank, vessel or surface clean and ready to be re-coated.

This system is most suitable for large surface areas and has a climbing capability up to 30 metres. It is perfectly suited for treating domed or floating tank roofs.

Technical advantages

  • UHP water blasting provides a surface free from non-visible contamination (chlorides, salts of ferrous oxide and ferrous chloride).
  • Produces a perfect surface on which to apply protective coating.
  • An ultra high pressure water jet also creates microscopic pockets on the steel surface to which protective coatings more readily adhere. A chemically clean surface with the correct profile means that any coating or lining material will bond more effectively and failure frequency is dramatically reduced.
  • It can prepare steel surfaces to ISO 8501-4 standards and Wa2½ surface finish is easily achieved.
  • RGL’s Limpet crawler system requires no scaffolding or sheeting.

Typical applications

  • Storage tanks and vessels.
  • Road and rail bridges.
  • Ships, submarines, aircraft carriers and other marine vessels.
  • Tidal defences and other marine structures.
  • Towers.
  • Pipe lines.

Compared to abrasive blast cleaning

  • Typically 25% cheaper – no need for erection/dismantling of scaffolding, sheeting or labour-intensive abrasive blasting processes.
  • Abrasive blast cleaning produces a spark – some tanks containing vapours or flammable liquids need to be shut down/emptied while surface preparation is being undertaken, hydroblasting does not produce any sparks.
  • The abrasives and contaminants from blast cleaning fall to the ground (or are wind dispersed) and have to be recovered and waste managed.
  • For every one ton of waste produced by hydroblasting, 200 tons of waste is produced by abrasive blast cleaning.

 

For more information please see our ebrochure: Preparation & Protection for Steel Structures Brochure

Need a Coatings Removal & Surface Preparation quotation?

Briefing guide

Fill out our enquiry form to get a quotation.

Make an Enquiry Now