There's a video on Youtube of some guy blowing vape smoke through various filter types. Pretty much all of them pass it, up to HEPA filter types for vacuums and medical respirators. Some filters I tested will filter particles down to the size of smoke, but Corona-19 is 1/10th of a micron across, which is smaller. It does get filtered by various materials, but those materials need to use static cling to filter. If they don't, the virus will pass through, given the hole size of the material.

If you are hanging around and talking to someone at a fairly close distance, masks simply won't do anything other than visually signal distance is required to others. And, in the unlikely event someone sneezes or coughs, it probably prevents widespread contamination of the surrounding area.

The Seattle choir episode and some studies out of China in restaurant air handling systems seems to indicate the virus is airborne and can be spread to others within a fairly large area, with time and proper airflow. This will happen with or without a mask in place, in my opinion.

I'm super nervous about sharing indoor space with people I don't know, so I don't. The more time we can buy ourselves, the better the outcome.