You've got to wonder about a sanding tutorial that starts off with 2000 grit sandpaper. It gives one a different appreciation for the word "smooth". I don't know if I'll be buffing with 2 grades of polishing compound, but I'll probably try for a better finish than I was originally planning on. Thanks for the link Javeryh. You mentioned "a few mistakes". Could you elaborate?
Sure. First off, I couldn't find 2000 grit sandpaper so I had to "settle" for 1500 which I found at NAPA along with the rubbing compound and polish (it's an auto parts store). The 1500 worked great - I can't imagine anything smoother. I wish I could capture it with my digital camera but I just can't seem to get a good shot of it. The finish is mirror-like but it's definitely not like a mirror... if that makes any sense. You can see your reflection but it's not totally obvious unless you are looking for it. Plus, I used a pink enamel-based paint for my base which my not be as reflective as the black enamel-based paint that the example I linked to showed. Also, I will not be using this process on the inside of my cab around the monitor where I will be painting black - I don't want the monitor to be reflected anywhere and be a distraction while playing.
One thing I definitely learned is that 220 grit and even 600 grit aren't really smooth (believe it or not). They are good enough for staining furniture that you will cover with a poly but if you want to apply a slick finish with no brush strokes or "orange peel" from spraying then a super high grit is the way to go. It is a perfectly flat, perfectly even finish - like straight out of a plastics factory or something. Definitely use a sander though - doing the whole thing by hand would be too hard, I think.
Now, there were three major mistakes I made the first time around that I think I've remedied this time (I have to sand and polish on Saturday so I'll let you know). All are related to sanding.
1. In my first test panel I can see very very tiny white spots in certain areas on the surface. This is a result of the primer showing through after the sanding process because the initial surface I used wasn't 100% flat/smooth. I'm using MDF. MDF is really smooth, right? I thought so but I guess not. The first mistake I made was not sanding the MDF surface completely smooth before applying any primer. On my second attempt I used a sanding block and 600 grit sandpaper to sand the entire surface of the MDF smooth. The difference is very noticable to the touch. Hopefully this will remove any "sand-through" spots.
2. The next mistake I think I made was not sanding at all in between coats of primer and paint. I think this makes a difference - even though I was using a high quality roller that appeared to be laying on an even coat I should have sanded each surfac smooth before recoating. This time I used 600 grit sandpaper to knock down the current layer of paint. I think this played a part in the white spots showing through because imagine putting on some primer but one dot dries higher than the rest - when you sand down when finishing it could show through because every other layer on top of that dot is on a higher plane.
3. The third mistake I think I made was not sanding the edges of the MDF prior to applying any paint. I noticed that when using the roller paint tended to collect along the edges of the MDF panel causing that area to be raised. When I sanded it down during the finishing process I ended up completely removing the pink paint in some areas near the edge. This time, I used 600 grit sandpaper and completely knocked off the corner edge of the panel - probably the equivilant of using a 1/32" chamfer bit or something. This edge will be built back up by layers of paint and then hidden by the t-molding or whatever else is normally used to hidge the ends of panels. Also, regarding the edges, I think I'm going to hand sand near the edges this time to be extra careful.
Going through the process once really gave me a feel for what I was doing and I think I've pin-pointed where I went wrong. With all that said, the panel still looks and feels amazing and I was very pleased with the results - I just want to make sure I get it perfect before trying it on my cab. I hope this helps.