Related above: Small business survival checklist — What you should do nowWhen the coronavirus struck the United States hard last month, 22-year-old entrepreneur David Zamarin knew his company needed a Plan B — fast. As the economy essentially shut down, demand for his stain-resistant coatings was sure to drop. So Zamarin decided to retool his company, DetraPel, in Framingham, Massachusetts, to start making disinfectants to