Method B: Visible Penetrant Post-Emulsifiable (Lithophilic)

Guide to Method B (lipophilic) processing per ASTM E-1417.

1. Pre Clean The Surface

Use Met-L-Chek® E-59A, R-503 or R-504 to remove oil, grease and other contaminants from the test surface. Part must be clean, dry, and at a temperature of 40-125°F (4.4-52°C) before penetrant is applied.

Products to Use: 

E-59A, R-503, R-504:

2. Apply Penetrant

Apply Met-L-Chek® VP-31A onto a clean and dry test surface using spray, immersion or wipe on. Wait a minimum of 10 minutes; 20 minutes if temperature is between 40-50°F (4.4-10°C) before proceeding to the next step.

Products to Use:


3. Apply Emulsifier

Apply Met-L-Chek® E-50 emulsifier by spray or flow on. Use a drain time of under 2 minutes.

Products to Use:


4. Wash

Wash the part.

  • Water Temperature: 50-100°F (10-38°C).
  • Water pressure: < 40 psi (< 275 kPa).
  • Wash Distance: > 12 inches (> 30 cm).

For Water-Based Developers go to step 4.A

For Non Water-Based Developers skip to step 4.B

4.A Water Based Developers

Apply Met-L-Chek® D-78B developer using immersion or spray prior to drying.

Products to Use: 


4.B Non-Water Based Developers

Dry the part to be inspected and then apply Met-L-Chek® D-70.

Products to Use: 


5. Inspect

Wait a minimum of 10 minutes before inspection.

  • Maximum time is 1 hour for form “f” (non-aqueous) developers.
  • Maximum time is 2 hours for form “c” (aqueous) developers.

If times are exceeded, clean part and reprocess. Use illumination of > 100 foot candles (>1100 lux/m2) to inspect.