This ultrasonic NDT couplant is designed for use on all types of metallic surface and is especially suited to solving the problems of rough, pitted, uneven surfaces to allow smooth probe movement during testing.

The thixotropic properties of this couplant give excellent wetting and acoustic transmission and do not allow the product to flow all over the test area; and so is very economical to use as you only cover the working area not the whole piece.


Sonagel W incorporates chemicals, which allow very slow drying even at elevated temperatures, whilst being free VOC’s and other hazardous materials. However, it does contain a special tracer dye to enable areas to be checked for coverage but the couplant is still easily removed with water or solvent wipes.

Sonagel W is available in easy to use 125ml applicator bottles, 250ml bottles, as well as in plastic 1 litre, 5 litre and 25 litre bulk containers (with suitable carrying handles)

Technical Specification

  • Water based yellow gel.
  • This product will have a flash point of 160°C when used for long periods at elevated temperatures.