What is an expected sign of proper glue application?

The correct answer highlights the importance of a uniform line thickness when applying glue in aviation or woodwork. A uniform line thickness ensures that the adhesive has been spread evenly across the surfaces to be bonded, which is crucial for achieving the best adhesion. When glue is applied properly, it forms a consistent coat that can properly bond the two surfaces, helping to enhance the structural integrity of the assembly.

In contrast, visible excess glue can indicate an over-application, which may lead to messiness and potential dripping, weakening the bond in some cases. Uneven glue distribution creates weak spots where the adhesive may not hold as effectively, compromising the strength of the joint. A dry glue surface suggests that the adhesive has either dried out before the joint was made or was not applied properly, which can result in a poor bond. Therefore, maintaining a uniform line thickness is an essential practice for effective glue application in woodworking and aviation contexts.