In brief: In December 2019 the first series of water-driven Bristle Blaster® Subsea units was ready to leave the MontiPower® factory for field deployment. The Subsea is a hydraulic, hand-held underwater tool, powered through a single neutrally buoyant high-pressure hose, that removes corrosion, coatings, scale and adhesive residue from steel and leaves a profiled surface for underwater coatings and repairs.
The first series of the MontiPower® water-driven Bristle Blaster® Subsea units is ready to leave the factory. We're looking forward to their deployment in the field. Below is a short overview of what the Subsea is, what it does and where it fits in underwater maintenance work.
What is the Bristle Blaster® Subsea?
The Bristle Blaster® Subsea is MontiPower's hydraulic underwater device with a water drive. Instead of an electric or pneumatic motor, a serviceable water motor turns the bristle belt. The tool is connected to a high-pressure power unit through a single, neutrally buoyant high-pressure hose, so the diver handles one line rather than a bundle of hoses and cables. Torque and speed are adjusted at the high-pressure unit on the surface.
The working principle is the same as on the topside Bristle Blaster® tools. Hardened wire bristle tips are accelerated against the surface, strike it and rebound. Each impact removes corrosion and coating and leaves a small crater in the steel. The result is a clean surface with an anchor profile, created in one pass and without loose abrasive. For a full explanation of the mechanism, see what is bristle blasting.
Why underwater surface preparation matters
Underwater coatings, splash-zone repairs and composite wraps depend on the same two things as any coating above water: a clean substrate and an anchor profile that gives the repair material something to key into. Below the waterline these are hard to deliver. Abrasive blasting under water needs dedicated equipment and leaves spent media in the water, and conventional hand tools tend to clean without profiling.
The Subsea is designed to close that gap. According to MontiPower's product data, it:
- removes corrosion, coatings, scale and adhesive residue;
- produces cleanliness comparable to ISO 8501-1 Sa 2½ or Sa 3;
- creates a profiled surface suited to the mechanical bonding of protective materials against corrosion;
- works without loose abrasive, so there is no blast media to contain or recover.
As with all bristle blasting, the actual result depends on the steel, the rust grade, the belt and the operator's technique, and should be verified against the repair or coating specification. Background on the method below the waterline is summarised on our underwater surface preparation study page.
Where the Subsea is used
The Subsea is aimed at maintenance and repair work where steel has to be prepared in place, under water:
- pipeline composite reinforcements and repair clamps on subsea pipelines;
- preparation for subsea welding activity on ships;
- port and harbour infrastructure;
- offshore structures in the marine and offshore sector.
Since this first series left the factory, the system has been developed further. Read about the hydraulic underwater device and the DNV offshore hydro unit that can power several Subsea tools at once.
Where to learn more
Subsea units and belts are supplied on request and project-specifically. For an overview of grit-free preparation below the waterline, visit our subsea preparation page. Subsea equipment and diving tools can also be rented; see tool rental.
Frequently asked questions
What is the Bristle Blaster® Subsea?
It is MontiPower's hydraulic underwater version of the Bristle Blaster®. A water motor drives the bristle belt, and the tool connects to a high-pressure power unit through a single neutrally buoyant hose. It removes corrosion, coatings, scale and adhesive residue below the waterline and leaves a profiled surface for protective materials.
What surface result does the Subsea produce?
MontiPower specifies cleanliness comparable to ISO 8501-1 Sa 2½ or Sa 3 and an anchor profile in the 65–85 µm Rz range on standard steel, the same principle and belt technology as the topside tools. Results under water vary with steel condition, rust grade, belt and diver technique, and should be verified on site.
Where is the Bristle Blaster® Subsea used?
Typical work includes preparation for pipeline composite reinforcements, subsea welding preparation on ships, port and harbour infrastructure, and subsea pipelines: any job where steel must be cleaned and profiled below the waterline without blasting media or containment. Units are supplied project-specifically and are also available through MontiPower's rental service.
Sources
- MontiPower, Bristle Blaster® Subsea product information and technical data (water drive, single neutrally buoyant hose, cleanliness comparable to Sa 2½ / Sa 3).
- MontiPower, Bristle Blasting for Underwater Corrosion Protection: the 2016 Study (summary of a German research study).
