A blasting machine for marine applications can be used to remove antifouling, old paints, rust, oxidation and encrustations from hulls, keels, boats and metal components. The machine must be chosen according to the material: fibreglass and gelcoat require a controlled jet, while steel and large structures may require greater removal capacity and autonomy. For small boats or localised operations, SABIX 8 may be suitable; for more extensive professional work, SABIX 28; WATER BLAST helps reduce dust dispersion, while SABIX 120 is oriented towards large surfaces and prolonged cycles.
Where blasting is used in the marine sector
In the marine sector, blasting is used during:
- ✓ Winter storage;
- ✓ Ordinary maintenance;
- ✓ Extraordinary maintenance;
- ✓ Refitting;
- ✓ Anti-corrosion restoration;
- ✓ Renewal of the antifouling cycle;
- ✓ Hull treatment;
- ✓ Treatment of keels and centreboards;
- ✓ Recovery of metal structures;
- ✓ Maintenance of components and equipment;
- ✓ Preparation before new painting cycles.
The most frequent applications include:
- ✓ Removal of old antifouling layers;
- ✓ Removal of non-adherent paints;
- ✓ Rust removal;
- ✓ Cleaning of metal parts;
- ✓ Treatment of oxidised surfaces;
- ✓ Removal of encrustations;
- ✓ Controlled opening of old protective cycles;
- ✓ Highlighting defects hidden beneath coatings;
- ✓ Treatment before primers, undercoats and new coatings.
Professional blasting is used both on pleasure boats and in shipyards, but the configuration changes radically according to the material and size of the hull.
Antifouling removal
Antifouling may consist of several overlapping layers, products of different nature, hard coatings, self-polishing products, old undercoats, primers, residues from previous repairs and areas with irregular adhesion. Before treatment, it is necessary to establish how many layers must be removed, whether the primer must be reached, whether the gelcoat must be preserved, whether the cycle must be completely removed, whether repairs are present, whether the surface has blisters, cracks or detachments and which new cycle will be applied. It is not always necessary to bring the hull back to the original material. In some operations, it may be sufficient to remove non-adherent parts, uniform the old cycle, eliminate excessive thicknesses and create a surface consistent with the next product. The objective must be defined before choosing pressure and abrasive.
Management of antifouling residues
The particles produced during antifouling removal must not be dispersed into the ground, water or neighbouring areas. Residues may contain biocides, copper, zinc, pigments, binders, substances from old cycles and contaminants collected from the hull. International guidance on the removal of antifouling systems indicates the need to work on impermeable surfaces, contain dust and residues and also collect contaminated water when wet methods are used. The yard must therefore provide tarpaulins or impermeable flooring, side containment, abrasive collection, collection of damp residues, protection of nearby boats, area segregation, correct waste classification and management, and cleaning without dispersion.
Hull materials
The chemical and physical nature of the substrate requires accurate modulation of impact parameters:
Fibreglass and gelcoat
Fibreglass consists of fibrous reinforcement and a resin matrix. Gelcoat forms the surface layer that protects and finishes the laminate. During antifouling removal, it is necessary to avoid wearing away sound gelcoat, exposing fibres, creating depressions, altering shapes, etching already thinned areas, widening cracks or damaging previous repairs. Blasting must start with a low-aggression abrasive, controlled particle size, reduced pressure, suitable nozzle, cautious distance, quick passes and a preliminary test. FEVI expressly emphasises the need for accurate control on fibreglass, gelcoat and sensitive marine surfaces.
Blasting and osmosis
Antifouling removal does not automatically coincide with anti-osmosis treatment. In the presence of blisters, delamination, liquid inside cavities, abnormal humidity, degraded gelcoat or previous repairs, a technical diagnosis is required. Blasting can be part of the cycle for removing compromised materials, but it does not identify the extent of the problem on its own, does not replace humidity measurement, does not define drying times, does not determine the reconstruction cycle and must not indiscriminately remove sound gelcoat.
Steel
Steel hulls and components may present corrosion, mill scale, old paints, primers, epoxy coatings, salts, contamination, localised oxidation and corrosion around welds. Blasting can be used to obtain the cleanliness grade and profile required by the new protective cycle. The following must be assessed: residual thickness, corrosion, welds, edges, roughness, salt contamination, interval before painting, temperature and humidity, and risk of flash rust. On steel, the use of water requires particular attention to immediate re-oxidation and compatibility with the subsequent primer.
Aluminium
Aluminium requires more controlled treatment than heavy steel. The main risks are excessive etching, deformation of thin sheets, localised heating, ferrous contamination, inconsistent roughness and alteration of the finish. Compatible abrasives, clean equipment, circuits not contaminated by iron, controlled pressure and distance and uniform passes must be used. Abrasive previously used on steel must not automatically be reused on aluminium.
Wood, keels and special components
Wooden hulls may have planks, caulking, joints, repairs, paints, impregnating products, degraded areas, different wood species and damp or friable parts. A jet that is too aggressive can erode the fibres, open joints, wear away caulking, round edges, highlight discontinuities and damage repairs and fillers. Blasting must be assessed only after a representative test and with a conservative configuration.
Cast-iron or steel keels may be affected by rust, old primers, antifouling, oxidation, fillers, repairs and localised detachments. In the presence of corrosion, it is necessary to check material, depth of degradation, condition of bolts, joint with the hull, subsequent epoxy cycle and time before recoating. Lead processing must not be approached like normal iron blasting. The production of dust containing lead requires specific assessment, containment, suitable respiratory protection, residue management and dedicated procedures. The simple availability of the blasting machine does not automatically make the process appropriate.
What result is required
The calibration of the pneumatic system varies according to the selectivity of action required:
- Complete cycle removal: This may be required when layers are incompatible, the coating is highly deteriorated, widespread detachments are present, a complete epoxy cycle must be carried out or the substrate must be checked. It is the most demanding operation and requires maximum control on fibreglass and gelcoat.
- Selective removal: This is used to remove flaking parts, excessive thicknesses, non-adherent areas, inconsistent repairs and localised contamination. It requires good ability to modulate the jet.
- De-oxidation and defect highlighting: On steel, cast iron and metal components, it may be necessary to remove rust, oxides, old primers and surface corrosion. The cleanliness grade must be consistent with the new protective cycle. Removing layers can also make fillers, cracks, blisters, old repairs, corroded areas and substrate discontinuities visible. Blasting does not correct these defects, but can make them easier to identify.
- Controlled roughening: The treatment can create a surface suitable for the subsequent primer. Excessive roughness can, however, increase coating consumption, leave exposed peaks, compromise the result or etch thin materials.
Blasting technologies for marine applications
The operating methods are divided according to the geometric shape and environmental restrictions of the yard:
Low-pressure blasting
It is suitable when a high level of control is required on fibreglass, gelcoat, small hulls, repaired surfaces, localised areas and delicate components. Reduced pressure alone does not guarantee delicacy. The result also depends on abrasive, nozzle, distance, angle, exposure time and jet flow rate.
Portable open blasting
Open blasting makes it possible to follow curves, keels, centreboards, skids, rudders, through-hull fittings and irregular surfaces. It is the most versatile technology from a geometric point of view. However, it requires screening, delimitation, collection, PPE, dust control and protection of nearby boats.
Blasting with dampened abrasive
Water is introduced into the air-abrasive mixture before outlet. The main advantages are reduction of dust lifting, greater control of the area, better management in yards and limitation of dispersion towards other boats. WATER BLAST is suitable for hulls, keels, painted surfaces and metal components in the marine sector. It uses a limited amount of water compared with traditional pressure-washing systems. However, contaminated water, wet abrasive, antifouling residues, drainage, flooring, drying, possible flash rust on metals and protection of systems and components must be managed.
High-autonomy, recovery and dry ice blasting
High-autonomy blasting is suitable when the hull is large, the cycle is prolonged, refills affect productivity, work is being carried out on steel, the yard has a suitable compressor and a confined area is set up. A large-capacity machine must not be chosen automatically for a fibreglass hull. Autonomy concerns cycle duration, while aggressiveness depends on adjustment, nozzle and abrasive. Recovery systems can be useful for small localised repairs, sufficiently regular surfaces, some strips, metal plates and work on flat components. It is not normally the first solution for a complete hull because the head must adhere to the surface and can encounter difficulties on curves and accessories. Dry ice can instead be assessed for engine compartments, components, equipment, organic residues, oils, grease and technical dirt. It does not replace abrasive blasting when resistant antifouling must be removed, deep rust eliminated or roughness created.
How to choose the abrasive
The selection of abrasive media affects the finish, recirculation and management of ecotoxic restrictions:
- Abrasive and fibreglass: On fibreglass and gelcoat, abrasives must be assessed that have controlled particle size, are sufficiently fine, are free from oversized particles, are compatible with the nozzle and can remove the coating without etching the substrate. The definition “delicate abrasive” does not automatically guarantee safe treatment. Even a relatively soft abrasive can damage the surface if used too close, with excessive pressure, with slow passes or with high dosage.
- Mineral abrasives and garnet: These can be assessed for metal hulls, keels, rust, resistant coatings and naval structures. Hardness and particle size must be consistent with material, roughness, new cycle, disposal method and possibility of recovery. Garnet and hard abrasives offer good removal capacity on steel, keels, structures and resistant coatings. On fibreglass and gelcoat, they must be used only after careful testing and with very controlled configurations.
- Vegetable granulates and bicarbonate: These can be assessed for some controlled operations on sensitive materials and relatively weak coatings. Bicarbonate can be considered in certain cleaning and light-removal applications; it produces a fine residue that must be accurately removed before the new cycle is applied.
Do not use generic sands: Materials that are damp, unclassified, irregular in particle size, undocumented or potentially containing crystalline silica must not be used. Marine blasting can expose the operator both to abrasive dust and to substances contained in the removed coatings.
Pressure, nozzle and compressor
Pressure must be defined according to hull material, antifouling, primer, abrasive, nozzle, distance and required result. On fibreglass and gelcoat, it is necessary to start from a reduced setting. A small nozzle concentrates the jet, facilitates localised work, requires less air and can create etching if kept still; a larger nozzle increases the working strip, productivity and demand for air and abrasive. A short distance concentrates energy; by increasing it, the jet spreads and point intensity decreases, improving control on sensitive surfaces. A nearly perpendicular jet concentrates impact more strongly, while a more grazing angle can help detach antifouling while reducing direct etching of the substrate.
The air compressor: The compressor must be sized considering machine, nozzle, pressure, continuous airflow, hose length, number of operators, cycle continuity and any distance between blasting machine and hull. An undersized compressor causes pressure drops, unstable jet, irregular dosage, low productivity and uneven results. Condensate and oil can agglomerate the abrasive, clog the line and contaminate the hull, making condensate separators and dryers necessary.
Dust, residues and safety
During marine blasting, abrasive, antifouling, paints, primers, rust, gelcoat, fibres, biological contaminants and metal residues may be dispersed. Dust and fragments from old antifouling coatings may contain ecotoxic substances and must not reach ground, drains or water. The yard must assess containment, impermeable flooring, tarpaulins, extraction, screening, abrasive collection, water collection, wind, distance from other boats, personnel access, waste classification and final cleaning. Depending on the process, blasting helmet, respiratory protection, breathable air, eye and face protection, hearing protection, gloves, suit, footwear, fall-arrest protection and systems for working beneath the hull may be required.
Technology decision table
| Requirement | Indicative technology | Why | Aspects to check |
|---|---|---|---|
| Small fibreglass hull | Controlled low-pressure jet | Greater control on gelcoat | Abrasive, distance and sample |
| Small or medium-sized boat | 28-litre portable blasting machine | Balance between autonomy and adjustment | Compressor and total surface |
| Yard with dust to contain | Dampened abrasive | Reduces particle lifting | Collection of water and residues |
| Large steel hull | High-autonomy open blasting | Reduces refills | Compressor, containment and roughness |
| Rusty keel | Abrasive open blasting | Good de-oxidation capacity | Material, corrosion and subsequent cycle |
| Sensitive gelcoat | Low pressure and controlled abrasive | Limits etching | Preliminary test |
| Localised and flat operation | Contact recovery | Contains abrasive and dust | Curvature and head adhesion |
| Refitting with multiple layers | Progressive jet | Allows selective removal | Primer, repairs and gelcoat |
| Area close to other boats | Dampened abrasive and screening | Better containment | Wind, drainage and collection |
| Large metal surface | 120-litre tank | Greater operating continuity | Airflow and organisation |
Four FEVI models recommended for marine applications
1. SABIX 8 – Professional low-pressure blasting machine
For small hulls and sensitive surfaces
SABIX 8 is a portable open-blasting machine designed for controlled processes and light or medium applications. The 8-litre tank, abrasive-flow adjustment and possibility of working from reduced pressures allow the jet to be adapted to surfaces that require particular caution. FEVI expressly includes marine applications among the fields of use of this model.
Marine uses: small hulls; fibreglass hulls; gelcoat; centreboards; rudders; localised keels; components; small boats; preliminary tests; selective operations; winter-storage work.
Strength: It offers good control of pressure, abrasive, dosage, intensity and treated area. The limited capacity also makes transport and use easier in the spaces of a boatyard.
Limit to assess: The 8-litre tank involves more frequent refills when the hull is extensive, the layers are numerous, the cycle is continuous or productivity is a priority.
Recommended user: small boatyard; maintenance technician; winter-storage company; professional working on fibreglass; operator carrying out localised operations; company needing a manageable machine.
2. SABIX 28 – Professional portable blasting machine
For hulls and medium-scale professional work
SABIX 28 is an open-blasting machine with a 28-litre tank, pneumatic abrasive-flow adjustment and vibration system. It can be configured with the Acquablast kit to dampen the jet. FEVI includes marine applications among the fields of use of this model.
Marine uses: small and medium-sized boats; hulls; antifouling removal; keels; centreboards; rudders; metal components; fibreglass; painted hulls; recurring professional work.
Strength: It represents a balance between autonomy, transportability, adjustment, continuity and possibility of using dampened abrasive. Compared with SABIX 8, it reduces loading pauses without reaching the footprint of a machine for large-scale work.
Data to consider: For a specific configuration, the Store data sheet reports: 28-litre tank; adjustable pressure; 3 mm nozzle; indicative air consumption of approximately 550 litres per minute at 7 bar. The data must be checked against the final configuration, nozzle and pressure actually used.
Limit to assess: It must not be considered automatically safe on gelcoat only because it is adjustable. Abrasive, pressure, distance, speed and removal level must be defined.
Recommended user: boatyard; refitting company; winter-storage company; professional blaster; maintenance technician working on multiple boats; operator seeking greater autonomy than SABIX 8.
3. WATER BLAST – Water-assisted blasting machine
For boatyards where dust must be reduced
WATER BLAST uses controlled abrasive pre-dampening to reduce dust lifting. FEVI specifically indicates it for hulls, keels, painted surfaces, metal parts, oxidised substrates and treatments before new protective cycles.
Marine uses: boatyards; hulls; metal hulls; keels; rust removal; old paints; antifouling; outdoor work; areas close to other boats; situations where dust must be controlled.
Strength: The main advantage is reduced particle dispersion compared with completely dry blasting. The water consumption indicated by FEVI is limited compared with traditional pressure-washing systems, but varies according to adjustment and work.
Limit to assess: Dust reduction does not eliminate the need to collect antifouling residues, contaminated water, wet abrasive, paints and oxides. On metal, it is also necessary to plan drying, flash-rust control, interval before primer and possible use of compatible products.
Recommended user: structured boatyard; refitting company; company working near other boats; operator who needs to reduce dust; metal-hull maintenance technician; marine blasting company.
4. SABIX 120 – 120-litre professional blasting machine
For large surfaces and shipyard work
SABIX 120 is an open-blasting machine with a 120-litre tank, designed for extensive and continuous work. It can be supplied with double or triple pneumatic remote control, allowing the operator to manage the machine from the work position. FEVI expressly indicates it for shipbuilding, painted surfaces, metal components and parts subject to corrosion.
Marine uses: steel hulls; large keels; naval structures; large boats; metal structures; metal components; extensive paint-stripping cycles; prolonged work; yards organised for open blasting.
Strength: The 120-litre tank reduces interruptions for abrasive loading. The advantage emerges when the surface is large, the work is continuous, the compressor is suitable, productivity justifies a larger-capacity machine and the yard has containment and collection systems.
Limit to assess: It is not the first proposal for small hulls, occasional operations, very sensitive gelcoat, areas without containment, yards with insufficient compressors or work requiring frequent movement of the machine. The 120-litre capacity does not determine treatment aggressiveness, but a configuration intended for high production must be controlled with particular attention on delicate surfaces.
Recommended user: shipyard; blasting company; marine metal-structure workshop; company working on metal hulls; operator handling large surfaces; company with suitable compressor and work area.
FEVI model comparison table
| Model | Technology | Recommended use | Strength | Limit to assess |
|---|---|---|---|---|
| SABIX 8 | Low-pressure open blasting | Small hulls, fibreglass and localised work | Control and portability | 8-litre autonomy |
| SABIX 28 | 28-litre open blasting | Hulls and small or medium-sized boats | Balance between autonomy and adjustment | Requires a correct test on gelcoat |
| WATER BLAST | Dampened abrasive | Yards with dust to contain | Reduction of dispersion | Water and contaminated residues |
| SABIX 120 | 120-litre open blasting | Metal hulls and large surfaces | Operating continuity | Compressor, containment and footprint |
Frequent mistakes when choosing
Mapping unsuitable operating behaviours protects the integrity of the artefact:
- Using an overly aggressive configuration on fibreglass: It can remove the gelcoat, expose the fibres and increase restoration work. Trying to eliminate all layers in a single pass is a mistake: the less adherent areas are removed first, while on the others the jet continues to etch the substrate.
- Choosing the machine only according to capacity or using the same abrasive: A blasting machine with a large tank offers autonomy, not necessarily greater precision. The two surfaces, fibreglass and steel, require different removal capacities and profiles.
- Not knowing the existing cycle or not collecting residues: Old antifouling coatings, primers and repairs can react differently. Dust, abrasive and antifouling fragments can contaminate the yard and the environment.
- Using water without arranging collection or applying primer immediately: Dust reduction does not eliminate the residue problem: it also transfers it into the process water. Before primer, dust, humidity, salts, roughness and contamination must also be checked.
- Using a recovery blasting machine on the entire hull or undersizing the compressor: The head can lose adhesion on curves, skids, centreboards and accessories. If the compressor is insufficient, pressure fluctuates and the result becomes difficult to uniform. Also remember to always protect through-hull fittings and valves to prevent abrasive intrusion.
FAQ on blasting machines for marine applications
Which FEVI blasting machine is most suitable for removing antifouling?
For professional work on small or medium-sized boats, SABIX 28 generally represents the most balanced proposal. It offers greater autonomy than SABIX 8 and allows abrasive flow to be adjusted. If the gelcoat requires particularly controlled treatment, SABIX 8 may be preferred. When dust is the main problem, WATER BLAST can be assessed, while arranging collection of damp residues.
Can a fibreglass hull be blasted?
Yes, but the process must be configured with particular care. The main risk is wearing away the gelcoat and exposing the laminate fibres. Abrasive, particle size, pressure, nozzle, distance and pass speed must be checked. It is necessary to start with a low-aggression test and gradually increase intensity. The presence of multiple antifouling layers does not justify immediately using a very incisive configuration.
What is the difference between SABIX 8 and SABIX 28 in marine applications?
SABIX 8 prioritises compactness and control and is suitable for small hulls, localised work and sensitive surfaces. SABIX 28 has greater autonomy and is more suitable for professional work on small and medium-sized boats. Tank capacity does not, however, determine delicacy: both must be adjusted according to material and coating.
Does WATER BLAST completely eliminate dust?
WATER BLAST reduces dust lifting by dampening the abrasive, but the result depends on surface, abrasive, pressure and water quantity. It is more correct to speak of reducing dustiness. In addition, the removed antifouling does not disappear: it must be collected together with the abrasive and water used.
When is it advisable to use SABIX 120?
SABIX 120 is suitable when large surfaces, metal hulls or naval structures must be treated with prolonged cycles. The 120-litre tank reduces refills and improves continuity. It is not normally the first choice for a first fibreglass boat, especially if the yard does not have a compressor, containment and suitable collection systems.
Does blasting solve osmosis problems?
No. Blasting can be used to remove antifouling, primer or compromised material, but it does not constitute an anti-osmosis treatment on its own. Diagnosis, humidity measurements, laminate assessment, drying and subsequent cycle reconstruction must be carried out. It is not correct to automatically remove all gelcoat without having defined the depth and extent of the problem.
Let’s identify the right blasting machine for your marine operation
The choice between SABIX 8, SABIX 28, WATER BLAST and SABIX 120 depends on the hull material, hull dimensions and cycle to be removed. To assess the configuration correctly, it is useful to tell us: type of boat; length; hull material; presence of gelcoat; type and number of antifouling layers; primer condition; presence of osmosis or repairs; keel material; total surface area; frequency of operations; need to reduce dust; possibility of collecting water; available compressor; subsequent protective cycle.
FEVI can verify machine, abrasive, particle size, nozzle, pressure, airflow and residue management together with the yard, building the solution around the actual hull and not only around the size of the blasting machine.
