If your PPGI coil arrives with paint or dimensional problems, the evidence you need is a documented chain: the mill test certificate and your purchase specification, retained samples from the approved lot, container and seal photos taken before opening, unloading records with timestamps, inspection and test data measured against agreed tolerances, and a clear timeline from arrival to the first observed failure. Suppliers can only resolve a claim they can verify, and verification depends on evidence that was captured before, during and after unloading — not reconstructed weeks later.
This article explains what makes a PPGI quality claim resolvable, how to organise that evidence, and where contract-specific requirements override general industry practice. It is written for importers, roofing-sheet producers, roll formers, procurement managers and engineers who need a defensible process rather than a hopeful one.
Why Most PPGI Claims Fail Before They Are Filed
A claim rarely fails because the defect is imaginary. It fails because the defect cannot be tied to a specific coil, a specific delivery, and a specific contractual requirement. Three gaps cause most disputes.
The first gap is timing. Paint defects such as blistering, peeling or colour drift may appear after forming, storage or installation. If the notification window in your contract has passed, the supplier may decline the claim regardless of cause. The second gap is identity. If coil tags, heat numbers or bundle markings are not photographed in place, a supplier cannot confirm the material is theirs. The third gap is measurement. Statements such as “the coating looks thin” are not actionable; a coating mass result in g/m² measured by a recognised method against a stated tolerance is.
Treat claim preparation as part of procurement, not as an emergency procedure. The cheapest claim is the one prevented by a clear specification and a documented receiving inspection.
The Evidence Package: What to Collect and When
Before shipment: contract and quality documents
- Purchase specification and signed order — substrate grade, metallic coating type and mass, paint system (primer, topcoat, back coat), nominal dry film thickness, colour reference, gloss range, tolerances, and inspection standard.
- Mill test certificate (MTC) — chemical composition and mechanical properties for the substrate, plus coating and paint data where the supplier provides it. Confirm whether the MTC is a certified original, a copy, or a manufacturer’s declaration.
- Approved pre-shipment sample — a retained colour and finish panel from the production lot, sealed, labelled and dated. This is the single most useful reference in a colour or gloss dispute.
- Inspection plan — who inspects, at what stage, using which method, and what constitutes acceptance or rejection.
During loading and shipment: container evidence
- Container number, seal number and seal condition, photographed clearly before the doors are opened.
- Photos of the container interior before and after loading, including dunnage, moisture protection and coil blocking.
- Any third-party pre-shipment inspection report, with the inspector’s identity and scope stated.
On arrival: unloading and receiving records
- Date and time of arrival, container opening, and completion of unloading.
- Photographs of every coil tag, bundle marking and heat number in position.
- Photos of visible transit damage — dents, edge deformation, wrap tears, rust staining, condensation, wet packaging.
- Weather conditions and any delay between arrival and unloading. Condensation-related corrosion claims often hinge on this record.
- Signed unloading sheet listing coil count, apparent condition and any exceptions noted at the time.
After arrival: inspection and test data
- Coating mass or thickness results, with the instrument, calibration status and number of readings per coil.
- Paint adhesion test results, with the method, location, and photographic record of the tested area.
- Colour and gloss readings against the approved retained sample, using the same instrument and geometry.
- Dimensional checks — thickness, width, camber, edge condition, coil inner and outer diameter, coil weight.
- Forming or processing trials, if the defect appears only after roll forming, slitting or profiling.
Store samples in dry, labelled conditions. If a laboratory test is required, agree the laboratory and method with the supplier before testing, so the result is accepted by both sides.
Building a Timeline From Arrival to Failure
A written timeline converts scattered evidence into a narrative the supplier can follow. Record, in sequence:
- Date of order confirmation and agreed specification revision.
- Date of pre-shipment inspection and sample retention.
- Date of loading, container and seal numbers.
- Date of vessel arrival and container release.
- Date and time of container opening and unloading.
- Date of receiving inspection and results.
- Date the defect was first observed, by whom, and under what conditions.
- Date of written notification to the supplier, with the evidence package attached.
Keep the timeline factual. Avoid conclusions about cause until the evidence supports them. If storage or handling conditions changed between arrival and observation — for example, coils moved to an open yard, or stored in a humid environment — record that too. It protects both parties.
Decision Table: Evidence by Claim Type
| Claim type | Primary evidence | Supporting evidence | Typical dispute risk |
|---|---|---|---|
| Paint colour or gloss deviation | Retained approved sample, instrument readings | MTC paint data, batch records, photos under controlled light | High — lighting and instrument differences |
| Paint adhesion or peeling | Adhesion test results with method and location | Forming records, storage conditions, timeline photos | High — cause may be forming or handling |
| Coating mass below specification | Coating mass test results, calibrated instrument | MTC values, sampling plan, number of readings | Medium — sampling and method disputes |
| Thickness, width or camber out of tolerance | Dimensional measurements with instrument record | MTC, coil tag photos, unloading sheet | Low to medium — measurement repeatability |
| Transit damage or edge deformation | Seal and container photos, unloading records | Carrier documents, insurance survey | Medium — liability between parties |
| Rust or white rust on arrival | Arrival photos, packaging condition, weather records | MTC, storage and transit duration, humidity exposure | High — cause often contested |
This table is general industry guidance. Your contract may require different methods, sampling frequencies or notification periods. Confirm the exact edition of any referenced standard and the exact values agreed in your order before relying on them.
RFQ Checklist: Ask Before You Order
Including these points in your RFQ reduces the chance of a claim and shortens resolution if one occurs.
- Exact substrate grade and mechanical property requirements.
- Metallic coating type and mass, with the test method and sampling frequency.
- Paint system description: primer, topcoat, back coat, and nominal dry film thickness per side.
- Colour reference method and gloss range, with a retained sample agreed before production.
- Dimensional tolerances for thickness, width, camber and coil weight.
- Inspection standard, edition, and whether a third-party inspection is permitted.
- Documents to be supplied: MTC, inspection certificate, packing list, and any test reports.
- Notification period for claims, and the required evidence format.
- Packaging specification: eye-to-sky or eye-to-wall, moisture protection, edge protection, dunnage.
- Retained sample arrangement and who holds the reference sample.
- Dispute resolution route and the agreed testing laboratory, if any.
For material selection context, compare product options such as PPGI coil and GI coil against your end use, environment and forming route before finalising the specification.
Common Mistakes That Weaken a Claim
- Opening the container without photographing the seal. Once the seal is broken, the link between the shipment and the supplier’s dispatch record becomes harder to prove.
- Removing coil tags before photographing them. Tag numbers are often the fastest way to trace heat numbers and production data.
- Cutting or processing suspect coil before inspection. Processing changes the material and can be argued as the cause of the defect.
- Relying on verbal notification. Send written notice within the contractual period, with the evidence attached.
- Testing without an agreed method. A result from an unagreed method may be rejected even if it is technically sound.
- Discarding the retained sample. Without a reference, colour and gloss disputes become opinion-based.
- Mixing coils from different lots. Keep lots separated and labelled so a defect can be isolated to one production batch.
- Missing storage records. If coils were stored in damp or exposed conditions, the supplier may attribute corrosion to storage rather than supply.
How to Present the Claim to the Supplier
Send one structured package rather than a series of messages. A workable structure is:
- Header: order number, invoice number, coil numbers, quantity affected, date received.
- Specification reference: the exact requirement not met, quoted from the order.
- Evidence: MTC, retained sample reference, container and seal photos, unloading records, test data.
- Timeline: arrival to first observation, with dates and responsible persons.
- Requested remedy: replacement, credit, rework, or joint inspection — as permitted by the contract.
- Response deadline consistent with the contract terms.
Keep the tone factual. Suppliers respond faster to a clear, evidence-based file than to a general complaint. If a joint inspection is proposed, agree the scope, method and laboratory in writing before it takes place.
FAQs
What is the single most important document in a PPGI claim?
The purchase specification, because it defines what was agreed. The mill test certificate, retained sample and inspection data only have meaning when measured against a stated requirement. Without a specification, both parties argue from assumption.
Can I claim for paint defects found after roll forming?
Possibly, but the burden of evidence is higher. You will need to show the defect was present in the coil or caused by the supplied paint system, not introduced by forming parameters, tooling condition or handling. Records of forming settings, tooling maintenance and the timeline from arrival to forming all help.
How long do I have to notify the supplier?
This is contract-specific. Notification periods vary widely and may differ for visible defects found at unloading versus latent defects found after processing. Check your order terms and confirm the period before shipment, not after a problem appears.
Do I need a third-party inspection report?
Not always, but an independent report can strengthen a disputed claim, particularly on coating mass, adhesion or dimensional tolerance. Agree the inspection scope, method and laboratory with the supplier in advance so the result is accepted by both sides.
What if the defect only affects part of a coil?
Isolate and label the affected section, photograph it in place before cutting, and record its position relative to the coil. Partial-coil claims are common and are usually resolved faster when the affected length or mass can be identified.
Does price affect how a claim is handled?
Price reflects cost drivers such as substrate grade, metallic coating mass, paint system, coating thickness, tolerance control, packaging and inspection scope. A lower-cost specification may legitimately have narrower margins on some properties, so agree the exact values rather than assuming equivalence. Request a dated quote that states the specification, tolerances, documents and claim terms in writing.
Next Step
If you are preparing an RFQ or reviewing an existing specification, send your requirements — substrate grade, coating mass, paint system, tolerances, inspection standard and required documents — and ask for a dated quotation that states each value explicitly. Clear specifications and a documented receiving process are the two most effective ways to make any future claim resolvable.
Contact ChinaCNU Steel with your coil specification and claim-handling questions, and we will respond with the information needed to compare options on a like-for-like basis.
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