How to Achieve SSPC-SP10-Comparable Results Without Sandblasting

This guide explains exactly how to achieve results comparable to SSPC-SP10 using the Bristle Blaster® — the step-by-step procedure, the equipment required, the verification process and the documented evidence that the method delivers specification-grade results.

When Sandblasting Is Not the Answer

There are four distinct situations where abrasive blasting is unavailable or inappropriate:

ATEX Zone 1 environments. Abrasive blasting is prohibited in explosive atmospheres under the ATEX Directive (2014/34/EU) and IEC 60079. The kinetic energy of abrasive particles impacting metal can generate ignition-capable sparks in a gas- or vapour-rich atmosphere. Any maintenance work on operating offshore platforms, active refineries, LNG terminals or petrochemical plants in Zone 1 requires an ATEX-certified alternative. See our full guide on ATEX Zone 1 surface preparation requirements.

No containment possible. Blasting requires containment of abrasive media and dust — either blast enclosures, vacuum blasting shrouds or temporary tents. On maintenance welds on a bridge, a structural repair on an operating plant, or a pipe repair in an enclosed space where media containment would require days of scaffold and sheeting work, the mobilisation cost makes blasting disproportionate to the job size.

Pipeline field joints. During pipeline construction or rehabilitation, each field joint (the bare steel zone adjacent to a circumferential weld) must be prepared and coated before burial. Mobilising full blast equipment for a 300–600 mm wide preparation zone on each joint is logistically and economically impractical in field conditions.

Abrasive contamination risk. In facilities where abrasive media contaminating adjacent process equipment is a production or safety disqualifier — pharmaceutical plants, semiconductor facilities, food processing, aerospace maintenance — the grit-free method is the only viable option regardless of area size.

The Method: Bristle Blaster® for SSPC-SP10

The Bristle Blaster® achieves surface cleanliness comparable to SSPC-SP 10 through high-velocity wire tip impact. Hardened steel wire tips rotating at high speed (approximately 2,500 RPM) create a micro-crater surface profile indistinguishable in function from abrasive blast profile — angular, omnidirectional and high-density. No abrasive media is required or generated.

The pneumatic model (Bristle Blaster® Pneumatic) carries ATEX certification Ex II 2G c IIA T4 X for use in Zone 1 explosive atmospheres. The electric model (Bristle Blaster® Electric, 120V/240V) delivers equivalent surface results in non-ATEX environments without requiring a compressed air supply.

Step-by-Step Procedure

Step 1: Assess the substrate

Before beginning preparation, identify the steel’s original rust grade according to ISO 8501-1:

• Grade A — new steel with intact mill scale, little or no visible rust
• Grade B — steel with mill scale beginning to rust and some pitting under examination
• Grade C — steel with general rust from which mill scale has largely removed but without pitting visible under examination
• Grade D — steel with general rust with pitting visible under examination

Grade A and B steel requires a single pass with the Bristle Blaster® to achieve cleanliness comparable to SSPC-SP 10. Grade C and D steel with heavy loose rust may require a preliminary de-rusting pass — see Step 2.

Step 2: Remove heavy corrosion (if required)

For Grade C or D steel with thick, loose or flaking rust deposits, fit the Tercoo® disc to the Bristle Blaster® drive unit and make a first pass before switching to the Bristle Blaster® belt. The Tercoo® disc removes bulk rust, old coating, tar and epoxy layers efficiently — without generating heat — reducing the load on the Bristle Blaster® belt and improving the quality and consistency of the final SP10-comparable result. Changeover from Tercoo® disc to Bristle Blaster® belt on the same drive unit takes approximately 30 seconds (typical; actual time depends on tool configuration).

If no heavy corrosion is present (Grade A or B), skip directly to Step 3.

Step 3: Set up the Bristle Blaster®

Select the correct model for your environment:

• ATEX Zone 1: Bristle Blaster® Pneumatic (Ex II 2G c IIA T4 X). Connect to air supply at 6.2 bar (90 psi). Verify the compressor is located outside the Zone 1 boundary or carries equivalent ATEX certification.
• Non-ATEX: Bristle Blaster® Electric (120V or 240V). Ensure the power cable is secured away from the work area and the tool guard is in place.

Inspect the belt for wear before starting. A worn belt produces a lower and less consistent profile. Replace the belt if tips show significant rounding or if it has completed its rated service life.

Step 4: Apply the Bristle Blaster®

Work in overlapping passes at 50% lateral overlap. Move the tool at a controlled, steady pace — approximately 1 cm/sec forward motion. Avoid dwelling in one position (overtreatment) or moving too fast (incomplete coverage).

On pipe surfaces, work circumferentially around the pipe in overlapping bands. On flat plate or structural steel, work in a systematic pattern of parallel passes. Apply the tool at approximately 90° to the surface — tangential application reduces profile depth and profile consistency.

For the Two-Step MontiPower Method on pipeline field joints: cover the bare steel zone plus a minimum 25 mm overlap onto the existing factory coating on each side. This overlap ensures the field joint coating can bridge onto the prepared surface and bond effectively at the transition.

Step 5: Inspect and verify cleanliness

After completing the preparation pass, remove loose debris with clean, dry compressed air or a soft brush. Do not touch the prepared surface with bare hands — skin oils can contaminate the steel surface.

Compare the surface against the Sa 2½ photographic reference panel for the appropriate original rust grade in ISO 8501-1 under adequate lighting (minimum 500 lux). The surface should show the characteristic matte grey of clean, impact-profiled steel with no visible mill scale lustre, no visible oxide colour and less than 5% random light staining.

Step 6: Measure anchor profile

Apply Testex Press-O-Film® X-Coarse replica tape (range 40–115 µm) using ASTM D4417 Method C:

1. Press the tape firmly onto the prepared surface. Burnish with the Testex applicator — minimum 20 strokes in two crossed directions.
2. Peel the tape and place it in a calibrated flat-anvil micrometer.
3. Read the total thickness. Subtract 50 µm (tape substrate) for the profile value.
4. Take minimum 3 readings per representative area. Record all readings and the mean.

Expected results on API 5L pipeline steel: 65–85 µm Rz. Compare the measured value against the coating manufacturer’s TDS specification for the system being applied.

Step 7: Measure soluble salt contamination

Apply a Bresle patch (ISO 8502-6) over the prepared surface. Inject 3 ml of distilled or deionised water using the included syringe. Agitate for 10 minutes. Withdraw the extract and measure conductivity with a calibrated conductimeter (ISO 8502-9). Convert to µg/cm² equivalent sodium chloride.

Compare against the coating TDS limit. Typical limits: marine and offshore systems <5 µg/cm² (total salts), pipeline sleeve systems <3 µg/cm² chlorides. If the measured value exceeds the limit, wash the surface with fresh water, dry, and repeat from Step 4.

Step 8: Apply the coating within the recoat window

The prepared surface must be coated before flash rust forms. The maximum allowable time between preparation and coating is defined by the coating manufacturer’s TDS — typically 4 hours in dry indoor conditions, 1–2 hours in humid or coastal environments. In high-humidity coastal or offshore environments, monitor the steel surface temperature and dew point and apply the coating before the surface temperature drops within 3°C of the dew point.

Step 9: Document the inspection

Record the following for project quality documentation:

• Date, time, location of prepared area
• Original rust grade and preparation method
• Cleanliness grade achieved (Sa 2½ confirmed against ISO 8501-1)
• Profile readings (method, tape grade, individual values, mean)
• Salt test results (method, value, limit)
• Ambient conditions (temperature, RH, dew point)
• Inspector identification

Documented Field Results

What the Inspector Will Measure — and What to Expect

A coating inspector verifying surface cleanliness comparable to SSPC-SP 10 on a Bristle Blaster®-prepared surface will use the same instruments and the same criteria as for a blasted surface. There is no different inspection protocol for grit-free preparation. Note: soluble salt testing (Bresle patch, ISO 8502-6) should be performed with a minimum of two extraction cycles — a single extraction underestimates salt burden on profiled steel. The inspector will:

• Compare the surface visually against ISO 8501-1 Sa 2½ reference panels — and will find a clean, matte grey surface with angular texture
• Apply Testex XC tape and read the profile — and will typically find 65–85 µm Rz on API 5L or structural steel
• Run a Bresle salt test — and may find low residual chloride levels on a surface prepared in normal field conditions; exact values depend on initial contamination level and whether a surfactant pre-treatment was used (see MontiPower Dr. Prepper No. 4)

For a full understanding of the SSPC-SP10 standard and all its requirements, see our SSPC-SP10 complete technical guide. For a direct comparison with conventional sandblasting on the key technical parameters, see Bristle Blaster® vs. sandblasting.

Frequently Asked Questions

How many passes does the Bristle Blaster® need to achieve cleanliness comparable to SSPC-SP 10?

On Grade A or B steel (intact or partially rusted mill scale), a single pass with 50% lateral overlap is sufficient to achieve cleanliness comparable to SSPC-SP 10 in most conditions. On Grade C or D steel (heavy rust, pitting), a preliminary pass with the Tercoo® disc followed by a Bristle Blaster® belt pass on the same drive unit is the recommended procedure. Do not make more than two passes with the Bristle Blaster® on the same area — additional passes do not significantly increase profile depth and can begin to work-harden the surface.

How long does the Bristle Blaster® belt last?

Belt life varies by steel condition and grade. On clean structural steel, a belt typically covers 40–80 m² before requiring replacement. On heavily corroded or hard steel, belt life may be 20–40 m². Always inspect belt tip condition before starting work on a new joint or section — a worn belt with rounded tips produces lower profile and less consistent results.

Can the Bristle Blaster® be used inside pipes or in confined spaces?

The standard Bristle Blaster® requires access for the tool body and operator. For pipe internal surfaces, MontiPower offers specialised configurations. For confined space work, verify that the ventilation requirements for the electric model (electrical safety) or the air supply requirements for the pneumatic model are met, and that the confined space atmosphere is monitored for oxygen level and combustible gases before and during use.