Water Path Control in Adhesive-Bonded Metal Panels- A Practical Guide
https://welding-quality-insights.evercolumn.com/posts/why-operator-training-matters-when-scanning-small-steel-parts
Water Path Control in Adhesive-Bonded Metal Panels: A Practical Guide Bonded metal sheets may need checks for changes in bond quality. Water carries sound between the transducer and the part without firm probe contact