'SSIC - Standard Subject Identification Code', All Acronyms, 17 January 2018, <https://www.allacronyms.com/SSIC/Standard_Subject_Identification_Code> [accessed 17 January 2018] Bluebook All Acronyms, SSIC - Standard Subject Identification Code (Jan. 17, 2018, 12:01 AM), available at https://www.allacronyms.com/SSIC/Standard_Subject_Identification_Code. CSE All Acronyms. SSIC - Standard Subject Identification Code [Internet]; January 17, 2018 [cited 2018 JAN 17].
Set your timer for 1 minute and wait. You can keep the etching cream on the glass longer and you will get a more intense etch, but the manufacturer (and I) suggest you start with the recommended 1 minute. When the minute is up, run the glass under luke warm water to remove the etching cream.
After the 3 coats the surface should be as smooth as glass. After the clear dries there should be no need to sand unless you have texture or dirt in the surface. If you have to, wait 24 hours and sand with 1000 to 2000 grit. Then buff the surface out with a buffing compound or hand glaze.