Soundproof enclosure for air compressor?

[John A. Callaway]

look up a website called second skin .... they make automotive sound dampening materials...

http://www.secondskinaudio.com/

They make a product called luxury liner that would suit your needs...

The owner is really friendly guy... shoot him a email and see what he recommends...

[david brum]

I made a box for my Rigid 2 1/4 hp (ridiculously loud) compressor using 1/2" plywood with soundboard stapled to the inside. The sound board was pretty cheap and works great. I also used some camming window latches to keep the door from rattling. That was a great help also. I can't measure the decibels but it is certainly below conversation level.

As others have said, do make sure to leave venting for heat. I also melted a shop vac before I discovered that the vent holes work best in the top of the box, where the heat wants to go.