I stuff cotton into all the holes where bolts went so I didn't accidentally get Herculiner into them then I laid down the first coat with a brush because I wanted to make sure I had enough Herculiner and also that I was able to get it into places the spray gun wouldn't fit. Also I broke out my headlamp so I could make absolute sure I was getting good coverage while doing the brush coat.
Total I used 2 quarts... The brush coat took just under a quart. The sprayed coat could have taken less, but I just went ahead and used it all up.
I just went at it in sections.. DAB DAB BRUSH BRUSH STIR STIR REPEAT!