Try a $35 angle grinder and a big wire CUP also. Yes your pic shows a lot of pitting, rust that is more than just surface,.... I suggest 80 grit for rust removal, but it can leave sand scratches th t need to be hit with something finer like 120 to get rid of scratches, They will show up in finish if not real careful, even heavy sanding primer will have trouble covering those scratches sometimes. . THOSE pitted areas, I will say it for last time, treat those with OSHO. A qt will cost you $12-13 or gal but $30. Just try it especially on pitted areas. Thanks and Done.
