How vibration and noise travel
Sound may travel through air, or be re-radiated by equipment connections, structure and panel vibration. Record the two paths separately first, then decide where to treat.
Why separate them
Damping coating treats the part radiated outward by panel vibration. If sound mainly enters as airborne sound through door gaps and ventilation routes, the coating does little; that needs its own absorption, insulation or sealing design. Coating before the path is clear risks the right material in the wrong place.
How to tell them apart
Record the sound and where it appears under different operating states, such as start-up, steady state and shutdown, or individual operation, combined operation and sailing. Where needed, measure panel vibration and the sound at the target position together, and record how both change with the operating condition as a lead for further investigation of the paths; the two changing together does not by itself show which path dominates.
What to record
Equipment status, load and running combination, where the noise appears, and how the equipment connects to the structure, with panel material and construction. This decides which part the coating should cover, and it is the basis for any later like-for-like comparison.
What to rule out first
Looseness, friction or poor installation of the equipment itself are not problems a coating can solve; equipment specialists should check them first. The coating only treats the step where structural vibration is radiated by panels.