How to Sand Body Filler / Bondo Straight - From Start to Finish

A detailed explanation of how to begin your body work, how to get it straight and how to finish it. Includes tips and tricks that work every time with difficult panels, curves and body lines.
Tools and Supplies:
Small Air Sander/Grinder: https://www.harborfreight.com/5-in-high-speed-air-sander-68739.html
Large Electric Sander/Polisher: https://www.harborfreight.com/7-in-10-amp-variable-speed-polisher-62861.html
Grinding Discs: (36 grit) https://benchmarkabrasives.com/collections/aluminum-oxide-resin-fiber-discs/products/7-x-7-8-aluminum-oxide-resin-fiber-disc-25-pac
Bondo / Body Filler: Auto Body Master Lightweight Body Filler (Auto Value Stores) $19/gal
10" Sanding Board: (Medium Length One) https://www.tptools.com/Professional-Straight-Board-Sanders,461.html?b=s*sanding+board
Masking Tape: 3M Automotive Refinish Tape
Primer: Auto Body Master Lacquer Primer $50/gallon - makes 2 gallons with 1 gallon of lacquer thinner. I use: https://www.homedepot.com/p/Klean-Strip-1-Gal-Lacquer-Thinner-GML170/100198758
Spray Gun: https://www.harborfreight.com/20-oz-hvlp-gravity-feed-air-spray-gun-62300.html
Metal Spreaders: https://www.autobodytoolmart.com/product/costers-steel-autobody-spreaders/body-filler-mixing-boards-spreaders?utm_source=feed&utm_medium=