AMPP CCAS cheat sheet

SSPC-SP 5/NACE No. 1 is white metal blast; SSPC-SP 10/NACE No. 2 is near-white; SSPC-SP 6/NACE No. 3 is commercial; SSPC-SP 7/NACE No. 4 is brush-off.

ISO 8501-1 blast grades correspond approximately: Sa 3 to white metal, Sa 2½ to near-white, Sa 2 to commercial, and Sa 1 to brush-off.

Soluble salts are measured by the Bresle patch method (ISO 8502-6/-9) or conductivity; chloride limits are project-specific and often 3–5 µg/cm², but the coating data sheet and specification govern.

Before abrasive blasting, oil, grease, and other contamination are removed by solvent cleaning (SSPC-SP 1) to prevent contaminant smearing or driving into the steel.

Steel temperature must be at least 3°C (5°F) above dew point, and relative humidity must be within the coating product data sheet limit, commonly ≤85%.

Surface profile is measured per ASTM D4417: Method A comparator, Method B stylus, Method C replica tape; typical blast profiles for industrial coatings are 1.5–4 mils (38–100 µm).

Compressed air for blasting or spray is checked per ASTM D4285 by directing air onto a white cloth; oil or water contamination must be eliminated before use.

Sharp edges, weld spatter, and rough welds are ground or treated because they cause thin film, holidays, and early corrosion; stripe coats are applied to edges and welds.

Wet-film thickness: WFT = DFT ÷ (volume solids fraction). Theoretical coverage (ft²/gal) = 1,604 × volume solids fraction ÷ DFT in mils.

Epoxy coatings generally have good chemical resistance but chalk under UV; aliphatic polyurethane topcoats provide color and gloss retention.

Zinc-rich primers protect steel cathodically and require a clean, blasted surface; they are not a substitute for removing soluble salts.

Pot life is the usable time after mixing; it decreases with higher temperature and ends when viscosity prevents proper application.

Recoat windows are product-specific; exceeding the window can require abrasion or another surface preparation step to restore adhesion.

Amine blush on epoxy is a water-soluble surface bloom from amine, moisture, and carbon dioxide; it must be removed before topcoating.

Immersion service coatings are selected for continuous water or chemical exposure; alkyds and many standard epoxies are not suitable for immersion.

Volume solids, not weight solids, determines dry-film thickness from wet-film thickness; weight solids include pigment mass and cannot be used directly in the WFT formula.

Airless spray pattern is controlled by tip orifice and fan angle; fluid pressure and tip wear change flow rate and film build.

Hold spray gun perpendicular to surface and overlap each pass by about 50%; distance typically is 12–18 in for airless spray, adjusted to product and equipment.

Plural-component equipment meters and mixes resin and hardener at a fixed ratio; incorrect ratio causes soft, tacky, or uncured film.

Stripe coats are applied by brush or spray to edges, welds, corners, and back sides before the full spray coat to build thickness at high-risk areas.

HVLP spray uses high air volume and low pressure, improving transfer efficiency and reducing overspray compared with conventional air spray.

Compressed air must be clean and dry; coalescing filters remove oil and water that cause fisheyes, poor adhesion, and contamination.

Brush and roller application require maintaining a wet edge and applying within the recoat window; roller marks and bubbles indicate improper technique or viscosity.

Equipment cleaning and flushing between materials prevent solvent contamination and cross-linking; the wrong solvent can damage seals and leave residue.

SSPC-PA 2 defines DFT measurement frequency and acceptance: spot measurements are averages of gage readings, with individual readings generally within 80–120% of specification and spot averages within specification.

Magnetic pull-off DFT gages require calibration on known shims or standards and correction for substrate curvature, edge effects, and surface profile.

Holiday detection uses low-voltage wet sponge for thin films and high-voltage spark testing for thicker or immersion films; voltage is set per standard and coating thickness.

Adhesion is assessed by ASTM D3359 cross-cut tape for thin films or ASTM D4541 pull-off for thicker systems; failure mode is reported with the numeric result.

Visual defect standards include ASTM D714 for blistering, D610 for rusting, D661 for cracking, and D4214 for chalking.

Environmental records during application include air temperature, relative humidity, dew point, steel temperature, and recoat times.

Solvent rub testing, such as MEK rub, checks cure; softening or removal indicates incomplete cure, but the specified solvent and rub count govern.

Common defects and causes: fish eyes from oil or silicone contamination; pinholes from solvent or air entrapment; sag from excessive WFT; dry spray from excessive distance or fast solvent.

Failure analysis sequence: verify surface preparation and salts, coating mixing ratio, DFT, cure, environmental conditions, and contamination before assigning cause.

The Safety Data Sheet provides hazard identification, composition, PPE, first aid, firefighting, spill, and disposal information under OSHA Hazard Communication.

Confined-space entry requires atmospheric testing: oxygen 19.5–23.5%, flammable gas below 10% LEL, and toxic contaminants below exposure limits before entry.

Silica abrasive blasting can cause silicosis; controls include silica-free abrasives, ventilation, respiratory protection, and exposure monitoring.

VOC and HAP content are regulated; low-VOC coatings reduce emissions but may have different viscosity, pot life, and application properties.

Flammable solvent handling requires bonding and grounding, ignition-source control, ventilation, and fire extinguishers.

Lead-based paint disturbance requires testing and lead-safe work practices; debris and blast media may be hazardous waste.

Respiratory protection follows OSHA 1910.134: fit testing, medical evaluation, cartridge change schedule, and supplied air for high exposures.

Fall protection is required when working at heights; guardrails, personal fall arrest, and training are part of OSHA requirements.