Hi

I'm not in SF, but I came across some libraries in San Francisco on Worldcat that contain back issues of The Blast. I've added links for each library so you can see the hours and get phone numbers etc.

Oakland Public Library Oakland, CA 94612 United States
Main Library Oakland History Room http://www.oaklandlibrary.org/Seasonal/Sections/mainhrs.html

San Francisco Public Library San Francisco, CA 94103 United States
http://sfpl.lib.ca.us/

San Francisco State University Library San Francisco, CA 94132 United States
http://www.library.sfsu.edu/

University of California Berkeley Berkeley, CA 94720 United States
http://lib.berkeley.edu/index.html

I imagine these libraries will also have some more anarchist materials.

-Natalie