a lil filler, some sanding, some glazing putty, some more sanding.. and then keep sanding till you are at 2000. primer it. resand 400, 600, 800, 1000, 2000
then shoot the hood. should take a pint.
Not sure where you learned that, but it's not the way it is normally done.
For dry hand sanding, body filler needs nothing finer than 220 grit before primer. Most technicians will never go finer than 150 grit sand paper on Bondo. And, primer needs nothing finer than 500 grit before paint. Many guys stop at 400 grit. Using anything finer than those for dry sanding, is unnecessary.
For wet sanding of primer, prior to paint, use 600 grit.
1000, 2000 grit sand papers are only used in body shops, for wet sanding clear coats, prior to buffing. (At least the ones who haven't figured out how to put the paint on nice enough to avoid all that).
If you need to use paper as fine as you suggested to do a good job, something is wrong.
We don't sand primer with 220, then sand it again with 360, then sand again with 400, then sand again with 600, and finer, then paint. If you are doing that, you are doing a lot of extra work. And that may be where you are going wrong.
The correct way for primer would be, say you need/want to sand it with 220 grit. Sand with 220. And, after you finish, reprime it. If you put on a nice smooth coat or two, you will only need to sand that with 400, or 500 grit dry, or 600 wet, and you can go right to paint.
We do it this way because, you can never be sure you removed every single 220 scratch no matter what you do. And since you can't paint over 220 scratches, you always reprime it, to fill them.