MASTER DRYWALL REPAIRMAN
I have performed many innovative experiments in my ventures. I am always looking for an easier way out. One such case came to me several years ago, there was a can light fixture hole left in a kitchen ceiling. This hole was about 4 inches round.
I applied fiberglass tape 3-4 layers thick, mixed up some 5 minute set powder compound for drywall patching, it also comes in 20-45 and 90 min sets. After applying about 1/16 thick coat, about ten minutes pass I went back up the ladder and pushed up the now swelled area. Another 5 min pass, I applied a coat of 20 min set, and it was ready for texture about 20 min later.
Note: You can also use any of the other powders it just takes longer,sometimes you can staple the tape to the drywall to hold it better.