Water-Washable, is the most economical method & it has not replaceable for rough casting surface, threaded & key surfaces.
- Water-washable or self-emulsifiable penetrants contain an emulsifier as an integral part of the formulation.
- The excess penetrant is removed from the object surface with a simple water rinse.
- Penetrant materials have the property of forming relatively viscous gels upon contact with water, which results in the formation of gel-like plugs in surface openings.
- While they are completely soluble in water, given enough contact time, the plugs offer a brief period of protection against rapid wash removal. Thus, water-washable penetrant systems provide ease of use and a high level of sensitivity.