Electroless and electrolytic are different routes
A request for nickel plating should state which process and functional characteristics are intended. Coating distribution, deposit properties and acceptance requirements depend on the system. Avoid selecting a route only from a desired silver appearance.
Preparation controls adhesion
Aluminum needs a suitable preparation sequence before nickel deposition. The casting alloy, porosity and machined surfaces can affect the result. Review the complete coating stack with the finisher and use actual cast samples for adhesion and appearance trials. Do not specify an unsupported proprietary preparation as a universal recipe.
Account for build and exposure
Set the required thickness and its measurement locations. Protect tight fits, threads and electrical contacts where appropriate. Review dissimilar-metal exposure and corrosion performance in the actual environment; a deposit that looks continuous is not proof that all service requirements are met.
Review checklist
| Review item | Define before release | Evidence to retain |
|---|---|---|
| Deposition route | Electroless or electrolytic and intended function | Approved coating specification |
| Substrate | Alloy, porosity and preparation | Adhesion trial |
| Dimension | Build, masking and final fits | Post-plating inspection |
Worked review example
For a plated bearing seat, establish whether the bore is masked or sized for the deposit. Inspect the final bore, not just the nominal nickel thickness on a separate coupon.
Apply the review to your drawing
Identify the affected features on the current drawing and attach the material, finish and operating requirements that control them. Agree the proposed route and acceptance evidence before releasing a change. Send the controlled files for a project review.