This almost looks like a huge spot of cancer, but it was actually a candle burn. We came in and sanded area 1st then vacuum and start applying 3 kinds of filler (none of which is the popular lowes brand). To be the best and complete in a timely manner, we use high end fillers! They dry quick,limited shrink and easier to sand! They more time spent applying,the less sanding!
We sand in between coats (wet).
Followed with our urethane epoxy