Defect to tool
| Defect | Usual cause | Prove with |
|---|---|---|
| Peeling / flaking | Weak profile or salts | Profile gauge, salt kit |
| Mud cracking | Excess WFT / DFT | DFT gauge |
| Holidays / pinholes | Thin film or spray technique | Holiday detector |
| Blistering | Osmotic salts | Chloride / Bresle kit |
Peeling after a “good” blast is usually salts, a profile outside the data sheet, or paint applied with steel at or below dew point. The tin is the last thing to blame. Measure: Bresle or kit for chlorides, profile gauge for anchor, DFT gauge for thickness, holiday detector for pinholes in linings.
Worked path: tank lining blistered at six months. Blast had been Sa 2.5 to the eye. Salt test on a remaining uncoated patch was high. Re-blast, wash as the spec allows, prove salts, then re-line. BLAST APEX sells the gauges and will run the same checks on a contract. NACE / SSPC / ISO here means methods on the job, not a company certificate on the door.