I've decided to finish the garage walls. The tape was coming off in most places so i've pulled that down. I have the tape, mud, pan, masks, bucket, sponge, drywall knives. I need to buy a pole sander attachment. I've never done this before but I think i need to sand down the existing dry mud from the previous installation first to start with a smooth even finish. Then i'll apply the mud and tape and sand and do it over again a million times. I've watched a few youtube videos. It'll be tedious but not rocket science. I just want general advice, do-s and don'ts. Like I have questions about how to make sure you stay straight when applying a super long tape to the ceiling. Do I need to fill in the larger holes like in the corners with something else? Why did they use like 4 layers of tape in an L shape in the corners instead of filling in the corners with some compound first so there is no weak points...
learn me...