NDT Cleaners for Aerospace Dye‑Penetrant Inspection

Dye‑penetrant inspection remains one of the most widely used NDT methods in aerospace. The cleaning stage is critical: the wrong cleaner can suppress fluorescence, create false indications, or compromise sensitivity. This guide explains how NDT cleaners work, how they differ, and how to select the right cleaner for your inspection process.

Why Cleaning Matters in Dye‑Penetrant Inspection

Cleaning is the foundation of penetrant inspection. Before penetrant is applied, the surface must be free from oils, machining fluids, dust, and residues. After penetrant dwell, excess penetrant must be removed without disturbing indications.

• Weak or missing indications
• Fluorescence suppression
• Developer contamination
• False positives and false negatives

Aerospace OEMs emphasise the same point: cleanliness determines sensitivity.

Types of NDT Cleaners

Aqueous Cleaners (NDT‑10)

Ideal for general inspection and water‑washable penetrants. Medium evaporation, zero residue, and excellent compatibility with aluminium, titanium, nickel, and steel.

Fast‑Evaporating Solvent Cleaners (NDT‑20)

Designed for high‑throughput inspection lines. Rapid drying and strong cleaning power. Classified as UN 1993 (Class 3 flammable liquid).

Precision Cleaners (NDT‑30)

Slow, controlled evaporation for high‑sensitivity fluorescent penetrants. Recommended for critical aerospace components where maximum sensitivity is required.

Choosing the Right Cleaner

• Penetrant type: water‑washable → NDT‑10; solvent‑removable → NDT‑20; high‑sensitivity → NDT‑30
• Evaporation speed: fast → NDT‑20; medium → NDT‑10; slow → NDT‑30
• Material compatibility: all WØB cleaners are compatible with aluminium, titanium, nickel, and steel

Product Comparison

Cleaner	Evaporation	Residue	Best For
NDT‑10	Medium	None	General inspection
NDT‑20	Fast	None	High‑throughput lines
NDT‑30	Slow	None	High‑sensitivity inspection

Developer Compatibility

WØB Aerospace NDT cleaners are compatible with:

• Dry powder developers
• Aqueous developers
• Non‑aqueous wet developers (NAWD)

They leave zero residue, ensuring consistent developer adhesion and accurate indications.

Frequently Asked Questions

What is an NDT cleaner?

A chemical used to remove contaminants and excess penetrant during dye‑penetrant inspection.

Does NDT cleaner affect penetrant sensitivity?

Only if it leaves residue. WØB cleaners evaporate cleanly and do not suppress fluorescence.

Is NDT‑20 flammable?

Yes — NDT‑20 is a Class 3 flammable liquid (UN 1993).

Can NDT cleaners be used on titanium?

Yes — all WØB Aerospace NDT cleaners are compatible with titanium, aluminium, nickel, and steel alloys.

Conclusion

Choosing the right NDT cleaner is one of the simplest ways to improve inspection accuracy. WØB Aerospace provides cleaners engineered for reliability, residue‑free performance, and compliance with AMS 2644 and ASTM E1417.