AMPP CIP Level 1 common mistakes
AMPP CIP Level 1 · Understand the traps and how to avoid them.
Determines environmental suitability by comparing the dew point to the air temperature on the hygrometer, never placing a contact thermometer on the steel.
Air temperature is already displayed on the gauge and is easy to note, while taking a steel surface temperature requires holding a magnetic probe on an awkward, hot or cold surface long enough for the reading to stabilize. Candidates therefore record the number that is easiest to obtain.
What to do instead
Treat air temperature and steel temperature as two separate measurements. Take surface temperature with a magnetic or contact thermometer at several representative points, calculate dew point from air temperature and relative humidity, and require the steel to be at least 3 degrees C (5 degrees F) above dew point before blasting or applying coating.
Uses white metal, near-white, and commercial blast as loose synonyms and cannot state the percentage of surface cleanliness each standard requires.
The adjectives read like points on a general scale of thoroughness rather than defined standards, and candidates memorize the names of the standards without the coverage numbers attached to them.
What to do instead
Memorize the standards as paired numbers: SP 5 / NACE No. 1 white metal requires a uniform 95 percent or better removal with no staining; SP 10 / NACE No. 2 near-white allows at least 95 percent removal with staining on no more than 5 percent of each unit area; SP 6 / NACE No. 3 commercial allows 66.7 percent removal with staining up to 33.3 percent.
Assigns ISO 8501-1 rust grades A through D from memory while comparing the surface to the visual comparator in direct sunlight or deep shade.
The letter grades are easy to memorize as a rough severity scale, so candidates stop actually matching the surface to the reference photographs and treat lighting as irrelevant.
What to do instead
Compare each unit area against the comparator under the lighting conditions the standard specifies (good daylight, not direct sun), and anchor the grades by description: A is mill scale with little or no rust, B is mill scale beginning to rust, C is rust with pitting starting, D is general pitting with rust.
Treats pot life, induction time, and recoat window as interchangeable time limits, or applies a second coat after the maximum recoat interval without abrading the first coat.
All three are time values printed close together on the same product data sheet, and the phrase pot life suggests working time after mixing rather than the total usable life of the mixed product.
What to do instead
Learn the three as separate definitions: induction or sweat-in time is the waiting period after mixing before application; pot life is the usable life of the mixed product; the recoat window is the minimum and maximum interval before the next coat. Read each value from the product data sheet for the specific coating and record the clock times in the log.
Diagnoses a spray defect by its appearance alone and prescribes thinner, when the mechanism could be solvent popping, dry spray, or poor atomization.
Defects such as pinholes, orange peel, and dry spray can look similar on a finished surface, and candidates reach for the additive they remember rather than working from the cause.
What to do instead
Work from mechanism to defect: solvent popping comes from trapped solvent in an over-thick film or on a hot substrate; dry spray comes from excessive distance, poor atomization, or too-fast solvent; orange peel comes from viscosity, atomization pressure, or gun technique. Confirm the cause from film thickness, gun settings, and temperature before proposing a fix.
Calculates dry film thickness from wet film thickness using the volume solids on the data sheet without correcting for thinner added on site, and accepts the calculated figure as the DFT.
The relation of wet film thickness times volume solids equals dry film thickness is easy to apply mechanically, and the as-supplied solids value is memorized as if it were a constant regardless of field thinning.
What to do instead
Correct volume solids for any thinner added in the field, treat the calculation only as a prediction of what should be achieved, and verify the actual dry film thickness with a calibrated gauge using the sampling rules of SSPC-PA 2 rather than reporting the calculated number.
Chooses a high-voltage spark tester for a thin architectural film or a wet-sponge tester for a thick immersion lining, based on whichever instrument is on site.
The term holiday detector is learned as a single tool, and the rule that test method follows film thickness and service environment is not intuitive from the equipment itself.
What to do instead
Match the method to the film: the low-voltage wet-sponge method suits thin films (roughly 20 mils / 500 micrometres or less) over conductive substrates, while high-voltage spark testing suits thicker films, with the voltage set from the coating's dielectric properties and measured thickness rather than guessed.
Takes dry film thickness readings with an electronic gauge on freshly blasted steel without checking the gauge against shims or adjusting for surface profile, then compares the average directly to the specification.
Modern electronic gauges appear self-calibrating, and the influence of anchor profile, curvature, and substrate on the reading is invisible on the display.
What to do instead
Verify the gauge with certified shims or foils on the actual substrate before use, apply any profile correction the manufacturer requires, and apply SSPC-PA 2 sampling: a defined number of spot readings per area, each spot averaged, with the spot average required to fall within 80 to 120 percent of the specified thickness.
Completes the inspection report with only a final pass or fail and a single overall thickness, omitting environmental readings, preparation grade, surface profile, and per-coat measurements; or signs off a hold point as though it were a witness point.
Documentation is viewed as paperwork completed after the work rather than a record built during it, and the difference between a hold point, where work cannot continue, and a witness point, where the inspector is notified but need not be present, is not practiced in the field.
What to do instead
Build the record as the job proceeds: ambient and surface temperature, dew point, relative humidity, preparation standard achieved, profile, and wet and dry thickness for every coat, plus batch and product data. At each hold point, stop the work until inspection is complete and signed; at witness points, confirm notification was given and record attendance.
Begins blasting inside a tank or other confined space wearing a supplied-air respirator but without atmospheric testing, a written entry permit, an attendant at the entrance, or a rescue plan.
The respirator is the most conspicuous piece of protective equipment, so it is treated as the complete control, and the permit, ventilation, and monitoring content reads as common sense and gets skimmed during study.
What to do instead
Treat the respirator as one element of a system. Before entry: obtain a written permit, test the atmosphere for oxygen, flammables, carbon monoxide, and hydrogen sulfide, set up forced ventilation, position a trained attendant with retrieval and communication equipment at the entrance, and confirm a rescue plan is in place.