AMPP CCAS common mistakes
AMPP CCAS · Understand the traps and how to avoid them.
Accepting an abrasive-blasted surface as complete after visual comparison to a cleanliness standard, without measuring soluble salt contamination and surface profile.
Visual cleanliness is the most obvious acceptance check, while salts and profile are invisible; under schedule pressure the candidate treats the visual comparator as the whole specification.
What to do instead
Before priming, record each acceptance item separately: visual cleanliness per the specified standard, soluble salt level by an appropriate field method, and profile depth by tape or replica. Reject and re-clean if any item fails.
Mixing coating by eye or using a partial kit, then applying without respecting the product's induction time or pot life.
Small repair quantities and leftover kits tempt approximate mixing; candidates memorize generic ratios instead of reading the product data sheet for the specific material.
What to do instead
Mix full kits at the specified ratio by weight or volume, allow the required induction time, mark the pot-life expiration, and discard material that gels or exceeds pot life.
Applying a high-build coating in one heavy pass to reach the target dry film thickness quickly, rather than using overlapping passes and checking wet film thickness.
Production pressure rewards speed, and a single heavy pass can look adequately covered; the candidate does not connect heavy passes to sagging, solvent entrapment, and holidays at edges.
What to do instead
Use the specified gun distance, angle, and speed with consistent overlap; check wet film thickness on the wet coat and adjust passes before the coating sets.
Taking dry film thickness readings with a magnetic gauge that has not been zeroed or checked against foils, and reading only at edges or on profile peaks.
The gauge appears to work and gives a number, so calibration is skipped; edge and profile-peak readings are convenient but not representative of the coated area.
What to do instead
Zero the gauge on bare substrate of the same material, verify with calibration foils, and take a sufficient number of readings on representative flat areas away from edges; record the average and range.
Converting wet film thickness to dry film thickness with a generic solids-by-volume figure and ignoring application losses.
The arithmetic seems simple, and candidates may not realize that the product's actual solids by volume and field loss factor differ from a generic value.
What to do instead
Use the product data sheet solids by volume and an appropriate loss factor for the application method, then verify the result with direct dry film thickness measurements.
Overcoating after the recoat window has expired without abrading or otherwise preparing the surface.
The previous coat looks and feels dry, and the schedule favors applying the next coat immediately; the candidate confuses dry-to-touch with a surface suitable for intercoat adhesion.
What to do instead
Track the recoat window from the product data sheet, test the surface if permitted, and if the window is exceeded, abrade or prepare the surface as specified before applying the next coat.
Labeling every blister as osmotic without checking soluble salts, solvent entrapment, or cure history.
Osmotic blistering is a familiar pattern, so the candidate stops at the visual appearance instead of gathering the evidence needed to distinguish causes.
What to do instead
Test the substrate for soluble salts, review mixing and induction records, verify dew point and cure conditions, examine blister fluid or a cross-section, and base the diagnosis on the combined evidence.
Skipping adhesion testing because it is destructive, or performing a pull-off test with poorly prepared dollies and misaligned loading.
Candidates fear damaging an acceptable coating and may not have practiced the test; poor dolly preparation and alignment produce invalid failures that are then misinterpreted.
What to do instead
Follow the applicable test method: prepare and clean the dolly and coating surface, cure the adhesive fully, align the pull-off fixture, and record both the numerical result and the failure mode.
Entering a confined space to coat or inspect without atmospheric testing, continuous ventilation, an attendant, or a rescue plan.
Confined-space work becomes routine on familiar tanks and voids, and solvent or abrasive dust hazards are underestimated because the space looks open enough.
What to do instead
Use a confined-space permit, test the atmosphere before and during entry, provide continuous ventilation, station a trained attendant, and confirm rescue arrangements before anyone enters.
Spraying or abrasive blasting without containment, and putting solvent or coating waste into general trash or drains.
Field crews focus on production and may not know the local VOC, waste, and stormwater requirements; containment is seen as an extra step rather than a compliance requirement.
What to do instead
Use appropriate containment and capture, segregate solvent and coating waste for authorized disposal, keep records, and verify that the coating system and application method meet the applicable VOC and environmental limits.