What an industrial sandblasting specification should resolve
An instruction to sandblast a part is incomplete unless the required result is clear. Identify the substrate, incoming condition, downstream coating system, required cleanliness and surface profile, and any restrictions on abrasive media or handling. Confirm the applicable project specification before work begins.
Machined fits, threads, sealing faces and thin or sensitive features may need protection or a different preparation approach. Send the drawing and identify these areas during quotation so the preparation plan can account for them.
- Describe rust, mill scale, old coating, oil and any known contamination.
- State the required cleaning standard and profile where the project specifies them.
- Identify protected surfaces and any dimensional or appearance constraints.
- Agree how prepared parts will be handled, stored and transferred to coating.
- Define inspection records and approval points before releasing production.
Why preparation matters
Powder coating cannot compensate for oil, loose corrosion, mill scale or an unstable existing finish. Contamination can interfere with adhesion, while an unsuitable surface profile can reduce coating performance. Preparation should therefore be specified as part of the coating system, not treated as an afterthought.
Typical preparation steps
- Inspection to identify the substrate, contamination and existing coatings
- Degreasing or cleaning to remove oil and process residue
- Stripping when an existing coating must be removed before refinishing
- Abrasive blasting or mechanical cleaning when the specification requires rust, scale or coating removal and a controlled profile
- Chemical pretreatment selected for the metal and performance requirement
- Drying, handling and masking controls before powder application
Information the coater needs
Identify the metal, current finish, service history and any sensitive surfaces. Let the coater know about weld residue, laser scale, silicone, cutting fluids, cavities and drainage concerns. Photographs help with an initial discussion, but production parts may still require inspection or a trial before the final process is confirmed.
Preparation and verification belong together
The selected process should connect directly to the final acceptance criteria. Visual inspection, film-thickness checks, cure verification and any specified adhesion or corrosion testing provide evidence that the complete system—not just the colour—meets the project requirement.