Shot blasting may be used to prepare an anchor chain surface when the method is suitable and accepted for the chain and maintenance scope. Removing rust or old coating does not restore lost metal, repair cracks or establish that a chain is fit to return to service.
Begin with Chain Identity and Condition
Identify the chain type, grade, dimensions, service history and applicable manufacturer, vessel or classification requirements. Establish the inspection and maintenance scope before choosing a cleaning process.
Marine exposure and mechanical contact can contribute to corrosion and wear, including at link contact areas. Record the condition before treatment, preserving identification and any findings that require examination. A cleaner appearance must not replace dimensional checks or other required inspection.
DNV’s anchor-loss guidance emphasizes inspection and maintenance of anchoring equipment and consultation with class when repairs are contemplated. Apply the requirements relevant to the actual vessel and chain rather than a generic maintenance claim.
Define What Blasting Is Intended to Achieve
The purpose may be removal of loose corrosion products or preparation for an approved subsequent treatment. State the required surface condition and inspection method. Separate surface preparation from decisions about repair, rejection or continued service.
Assess contaminants, including salts and old coatings, before blasting. A suitable preliminary cleaning procedure may be required. Blasting should not be assumed to remove every contaminant or to make a surface immediately ready for any coating.
Review Method and Link Access
Wheel blasting and air blasting offer different exposure and handling arrangements. Selection depends on chain geometry, load presentation, treatment scope and the permitted process. No method guarantees full coverage solely because abrasive reaches the visible outer surfaces.
Check the contact areas between links and any surfaces hidden by supports or neighbouring links. Determine whether controlled movement or repositioning is needed. Include those operations in the cycle and inspection plan.
Use suitable lifting and handling arrangements for the load. Review entanglement, moving-chain, abrasive and dust hazards. Extraction, containment and waste handling should reflect the material being removed and the workplace conditions.
Keep Inspection Separate from Coating Preparation
| Review stage | Evidence needed |
|---|---|
| Before treatment | Chain identity, condition record and approved work scope |
| Process trial | Suitable method, exposure and treatment parameters |
| After cleaning | Required examination and dimensional or other inspection results |
| Subsequent treatment | Approved coating or protection specification, if applicable |
| Release | Responsible acceptance decision and traceable records |
If further examination is required, confirm that the cleaning method is compatible with the specified inspection procedure. Refer suspected cracks, deformation, excessive wear or other defects to the responsible authority; do not increase blasting intensity as a repair method.
Apply Only the Specified Protection System
Any coating or other protective treatment must be suitable for the chain material, service and governing requirements. Follow its instructions for preparation, contamination checks, application and cure. Do not assume every anchor chain should receive a generic primer-and-topcoat system.
Protect the prepared surface during handling and storage. Inspect the specified treatment result before release. Blasting alone is not a barrier against renewed corrosion and cannot support a promised extension of service life.
Retain the Maintenance Record
Keep identification, preparation settings, inspection results, any subsequent treatment and the release decision together. The record should show what work was performed and who accepted the chain for its intended use. Surface cleanliness, chain condition and service acceptance remain distinct parts of that decision.
