Data Centers

Q: Does Innozinc prevent zinc whiskers?

Whisker prevention or suppression is not established here . Stress and microstructure can influence growth , but a reported 96% corrosion-rate difference in polarization testing does not measure whisker behaviour . Discoloration is not a validated predictor of whisker timing . Direct product-specific qualification is required .

Q: Why do SST figures differ between documents?

Confirm grade, specimen and acceptance criteria . White-rust and red-rust endpoints concern different corrosion observations and cannot be compared as equivalent hours . Current guidance is Innozinc: 720–1,000 hr; Innozinc-h: 1,500–2,000 hr . Request reports matched to your required endpoint ; do not assume the range endpoints were measured on the same specimen.

Q: Does an 8 µm deposit establish acceptable whisker risk?

No . Thickness-dependent results for a particular zinc deposit do not establish universal risk. The complete coating process, stress and microstructure matter. No thickness-specific Innozinc whisker qualification is provided here ; agree testing if required.

Q: Can polarization testing prove whisker suppression?

No. It evaluates corrosion behaviour under defined electrochemical conditions . It does not establish whisker initiation or growth rate . Agree a zinc-appropriate protocol with a qualified laboratory ; do not apply a tin-whisker standard as automatic zinc-coating certification.

Q: What does surface darkening mean?

Darkening requires an appearance and corrosion assessment . It is not a validated whisker warning system . No fixed darkening → whisker → white-rust sequence is established here. Inspect against the approved maintenance and acceptance criteria.

Q: Does a thinner coating necessarily last longer than HDG?

No. Coating systems differ , but the cited figures are laboratory test results , not direct service-life predictions. Review specimen details, acceptance criteria, exposure and wear before comparison.

Q: Is Innozinc-h better than SUS304?

Not as a general statement. SUS304 is a base material ; Innozinc-h is a surface treatment on steel . Galvanic behaviour depends on the full metal couple and environment . Confirm mechanical, corrosion and electrical requirements before considering substitution.

Q: Can we evaluate it without replacing our current supplier?

Start with one representative component or a defined project area . Agree sample terms and comparative acceptance criteria before any production change.

Why it matters

Four design considerations

Controlled rooms still require management of electrical contamination and electrochemical corrosion. Also consider fabrication, coating coverage and component assembly.

Zinc whiskers

Zinc whiskers are conductive metallic filaments that can grow from zinc-coated surfaces. Their growth and incubation vary. NASA has documented electronic failures associated with whisker contamination, including zinc-coated raised-floor structures. Assess the actual equipment and particle pathways.

Thickness alone does not determine whisker risk. Published experiments describe thickness-dependent behaviour under particular plating conditions, not a universal safe or unsafe threshold for all data-center components.

Define contamination controls before material approval Background references: NASA, Brusse & Sampson (2004); Takemura (1986); Wu, Ashworth & Wilcox (2015). These do not validate Innozinc whisker suppression.

Galvanic corrosion

Stainless-steel fasteners contacting zinc-coated steel can create galvanic interfaces when an electrolyte is present. The cited Innozinc-h comparison reported 65% lower galvanic current density with a carbon-steel counterface than its HDG reference. This value must not be attributed to an SUS304-bolt joint.

Assess electrolyte, area ratio and counterface

Salt and chemical exposure

Review salt, condensation and chemical exposure separately. Innozinc-h SST guidance is 1,500–2,000 hr. The cited 10% HCl, three-minute immersion result does not qualify continuous acid service.

SST: 1,500–2,000 hr · Chemical compatibility review

Cut edges and bends

Pre-coated Zn–Mg–Al sheet is cut and formed after coating. Review cut-edge coverage, bend damage and fabrication stresses. Although stress can contribute to whisker growth, it does not establish whisker behaviour for a particular sheet product. Obtain relevant supplier data.

Post-fabrication coating can cover accessible edges Background: stress and microstructure research; obtain product-specific data for any coating comparison.

Do not infer product performance from a general mechanism. Stress alone does not prove that whiskers will grow. The relevant requirement is evidence for the actual material, coating and fabrication conditions. Apply the same requirement to Innozinc and competing systems.

Mechanism 01 · Zinc Whisker

Whisker growth and corrosion
require different evaluations

Whisker growth can involve internal stress and microstructure. Reported stress thresholds and deposit stresses depend on the study conditions; they are not universal design limits. Electro-zinc coatings need application-specific risk review. KEMP's polarization comparison reported a 96% lower corrosion-rate estimate than its HDG reference, but did not measure whisker growth.

96%↓

Reported polarization comparison

Corrosion reference only; request method and original report

What this test can show

Polarization evaluates electrochemical corrosion behaviour under the test conditions. It does not measure whisker incubation, density, growth rate or electrical safety.

What the coating result does not prove

A comparison with a zinc-coated reference cannot establish delayed whisker initiation or slower whisker growth. Those claims require direct, product-specific evidence.

Reference SEM image of zinc whiskers near conductors — **Zinc whisker reference image**. Conductive filaments can bridge electrical conductors. This image is not an Innozinc product-qualification result.

Reported 480-hour salt spray comparison of ceramic zinc and electro-zinc coated supports — **480-hour salt spray reference**. The cited **electro-zinc specimen** showed red rust at 120 hours. Compare specimen preparation, thickness and acceptance criteria in the report; this is not a whisker test.

① Corrosion performance Not a whisker result

The coating system should be evaluated against the required corrosion and assembly conditions.

Coating structure — review zinc and inorganic-layer coverage. Claims about whisker diffusion paths require direct evidence.
Residual stress — confirm measured stress and microstructure where relevant; no product-specific whisker qualification is established here.
Corrosion behaviour — the reported 96% polarization difference applies only to the stated corrosion comparison, not whisker suppression.
Other coating studies — results for zinc–nickel or other systems do not establish Innozinc performance.

② Electronics-related qualification Component requirements

Define the qualification criteria for components near sensitive electronics.

Electrical conductivity of zinc whiskers — zinc whiskers are metallic conductors; the product name does not establish electrical insulation.
Electrical isolation at the component level — do not rely on an unqualified surface film as an electrical safety barrier.
Whisker penetration resistance — performance depends on the coating and must be validated directly.

Whisker suppression is not established on this page. Zinc whiskers are conductive metal filaments.

The available references are polarization testing and salt spray testing; neither directly measures whisker growth. If required, agree a zinc-appropriate protocol, controls and acceptance criteria with a qualified laboratory before making a performance claim.

Whisker qualification Required separately

Innozinc is not represented as whisker-free. Nor does reduced corrosion establish later initiation or slower whisker growth. Direct evidence is needed under relevant material, process and environmental conditions.

Surface discoloration Inspection trigger, not a whisker predictor

Darkening, white rust and whisker growth are not an established fixed sequence. Inspect discoloration against the agreed appearance and corrosion criteria. Visual inspection alone cannot establish whisker absence or timing.

Reference images of discoloration on a nominal 9 µm ceramic zinc coating

Separate the test purposes. Polarization concerns electrochemical corrosion behaviour, not direct whisker measurement. It does not establish a delay in whisker initiation or growth. Agree an appropriate test program from the sample stage where whisker control is required.

Zinc coating Conceptual layer illustration

Whiskers may create conductive contamination. The illustration does not predict growth rate or compare coating systems quantitatively.

Innozinc / Innozinc-h Conceptual coating structure

Electrodeposited zinc with an inorganic layer. Corrosion results do not establish whisker suppression.

Risk control is system-specific. Options can include qualified material selection, cleaning and protective coatings. Review particle sources such as raised-floor and overhead structures and the equipment's exposure pathways. A change in structural coating needs its own validation.

Do not assume any generic zinc coating is immune. Apply product-specific evidence and equipment requirements to all candidates.

Background references: Lindborg (1975/1976); Sugiarto (1984); Takemura (1986); NASA, Brusse & Sampson (2004); Lahtinen & Gustafsson (2005/2006); NASA NEPP; Wu, Ashworth & Wilcox (2015); Arroyo et al. (2021). Literature references do not certify Innozinc performance.

Product Lineup

Selecting Innozinc or Innozinc-h

Both use a ceramic zinc coating system. The appropriate grade, thickness and process depend on exposure, component geometry and acceptance criteria. Whisker-sensitive applications require separate qualification.

Innozinc

Standard grade · Application review required

SST guidance: 720–1,000 hr — confirm specimen and rust criteria
Galvanic interfaces: review the coupled metals and exposure
Reference deposit: 8 µm — specify thickness locations and verify thread fit
Topcoat compatibility: verify the selected paint system
Chemical screening: confirm report scope. Low-temperature processing reduces heat-related distortion risk.

Candidate applicationsIndoor trays, rack frames, channels, floor supports and hangers, subject to corrosion, electrical and contamination requirements.

Higher corrosion-resistance grade

Innozinc-h

High-corrosion-resistance grade · Not a stainless-steel substitute by default

SST guidance: 1,500–2,000 hr — confirm the supporting report and acceptance criteria
Galvanic comparison: counterface-dependent — reported 65% reduction applies to carbon steel
Chemical screening: review test conditions — 10% HCl immersion for three minutes does not qualify continuous acid service
Thickness, fit and painting: confirm the actual specification
Compare total component cost and qualification requirements before considering a change from stainless steel

Candidate applicationsCoastal, outdoor and condensation-prone supports or galvanic interfaces. Confirm salt and chemical exposure, materials and electrical requirements.

A project may consider Innozinc and Innozinc-h in different exposure zones. Share drawings and performance requirements to agree the specification and validation plan.

Data

Coating and material references

Catalogue references and current grade guidance. Comparisons require equivalent test conditions and acceptance criteria.

SST reference and grade guidance · Bars show upper values on a 2,000-hour scale; test endpoints differ

Zinc electroplating

240h

Hot-dip galvanizing

500h

Innozinc

720–1,000 hr

Innozinc-h

1,500–2,000 hr

SUS304 is a base material, not a zinc coating. Zinc white-rust criteria do not apply to it; the reference does not establish direct equivalence.

Item	Zinc electroplating	Hot-dip galvanizing	Innozinc	Innozinc-h	SUS304 (base material)
SST reference / grade guidance	240 hr (reference)	500 hr (reference)	720–1,000 hr	1,500–2,000 hr	Not a zinc white-rust criterion
10% HCl, three-minute screening	Poor (catalogue rating)	Poor (catalogue rating)	Fair (catalogue rating)	Good (catalogue rating)	Good (catalogue rating)
Polarization corrosion comparison	–	Reference: 100%	Reported 96% reduction	Reported 96% reduction	–
Galvanic comparison: test-specific rating	Poor (catalogue rating)	Poor (catalogue rating)	Good (catalogue rating)	Very good (catalogue rating)	Fair (catalogue rating)
Whisker qualification	Application-specific evidence required	Application-specific evidence required	Suppression not established	Suppression not established	Not a zinc coating
Coating Thickness	8µm↑	50~77µm	8µm↑	8µm↑	–
Fastener fit / tolerances	Verify specified system	Verify specified system	Verify specified system	Verify specified system	Verify specified system
Topcoat adhesion	Verify specified system	Verify specified system	Verify specified system	Verify specified system	Verify specified system
Process temperature / dimensional review	Ambient electrodeposition	Hot dipping, approximately 450°C	Ambient electrodeposition	Ambient electrodeposition	–
Chemical screening / compliance review	Specification-dependent	Specification-dependent	26-analyte reference; confirm report scope	26-analyte reference; confirm report scope	Confirm material compliance requirements

References include ASTM B117 salt spray conditions (5% NaCl, 35°C) and three-minute immersion in 10% HCl. Request the original KTR reports, including specimen preparation and the analytes actually tested. IEC 62321-6 is not a blanket test for all RoHS substances. These comparisons support review, not automatic approval.

Match acceptance criteria before comparing hours. White rust concerns zinc corrosion, whereas red rust concerns the steel substrate. A red-rust endpoint cannot be directly compared with a white-rust endpoint. Current grade ranges are not all guaranteed to one universal endpoint. Request reports matched to your acceptance criteria before specification approval.

Application

Component selection and qualification

Choose the grade by exposure and function; verify electrical, contamination and mechanical requirements separately.

Cable and mesh trays

Review whisker and particle requirements near electronics, cut-edge coverage and installation damage. No suppression claim is established here.