Automotive undercoating?

I used some spray on stuff to a mdf box for a non-speaker project and i found that it did not totally harden how i wanted it to. seemed to almost stay rubbery. though the stuff i used was a bit old i am sure.

yeah, it does kind of stay rubbery but does bond well and seems like it would be a good product for sealing allthough it does take for ever to dry. The thing i was kind of wondering if there would be any effects accousticly. Just kinda wondering what everyones 2 cents were.

Undercoating is sometimes used in car audio to help deaden a subwoofer enclosure, but it does not seal them. A commonly used substance for sealing the seams of an enclosure is silicone RTV or liquid nails.

If you use PL wood glue when you build it that should seal it up fine.

Thanks guys, i was just looking for an easy way to get into all the nooks.

Ive been using adhesive sealant during the build. Putting some in between the panels during the build, then sealing round the internal vertices seals the things perfectly. Your not relying on the paint/undercoat for anything then other than making it look good.

Automotive undercoating is a protective layer applied to the underside of a vehicle to guard against rust, corrosion, and road debris damage. It acts as a barrier, sealing vulnerable areas and extending the lifespan of the vehicle. Undercoating can be particularly beneficial in areas with harsh weather conditions and road salt usage.