Body work.
If you have painted before, You probably have the foundation needed to go from a good paint job to a GREAT one...it's patience and elbow grease. Make sure the body panel is as smooth as glass BEFORE painting by using guide coats.
Guide coat: A lighty applied dusting of primer in a contrasting color
Once the steel is properly prepped/sealed and primered(like you've done in the past im sure), use 2 or 3 extra (medium wet) coats of primer. Then, lightly dust the surface with a primer of a different color(rattle can primer works fine). Lightly wet sand the area with 1000 grit 3m wet paper using long even strokes(and a large HARD sanding board) in a diaganal pattern sanding only in one direction until 50-75% of the guide coat is gone. The remaining guide coat indicates where the low spots are. Reprimer the area and dust again. Repeat this process until the guide coat all comes off at the same time - no low spots.
Finish coats:
For my 67 fairlane, I used PPG base/clear using a 5HP craftsman 30 gallon compressor (which was grossly under powered - but usable) and a decent siphon fed gun. Make sure you remove all water from the compressed air with at least one inline filter/dryer - the ones I like are little orange balls that screw to the guns air inlet - with the use of inline dryer, increase pressure by 5 pounds over the recommended.
When you are done, wait a week and let the clear coat harden. Then comes the finish sanding.
Some tricks I have learned:
Wet sand in 2 foot by 2 foot sections using 1000 grit then 2000 grit.
Use a somewhat hard yet flexible sanding board no bigger than 3 inches by 3 inches - a small peice of 1/10" lexan will work but thats a little too hard to be ideal. You may need several boards with various amounts of flexibility depending on where you are - to accomodate curves.
Do not wetsand corners.
If you hear/feel the paper start to buzz, then there is debris under it and you need to stop and rinse.
Use a lot more water than you think you need.
Do the whole car in one grit before moving on to the next.
The point to wetsanding a clearcoat is to knock off all the little peaks and not touch the valleys - there may be a hundred peaks and valleys in a 1 inch square - like the peel of an orange.
When properly wetsanded, the finish will look ALMOST uniformly dull - Now its time for polishing.
I had someone else polish my fairlane and you can too, arrange with a body shop to have it buffed to a mirror finish for a couple of hundred bucks.
I learned this from a guy who takes brand new cars and preps them for the Detroit International Auto Show.
It took me 3 weeks to prep and paint the fairlane and one WHOLE day to sand and polish it out with the help of "Diamond Jim" He tried not to charge me but I paid him $200 for his invalueble knowledge and elbow grease.
Jim told me that I had better practice my polishing skills before trying it on something I cared about because it's real easy to "burn" through the clearcoat. I never even touched his polisher but it was a Milwaukee with variable speed. He polished it out with a back and forth pattern over the whole panel on a medium low polisher speed. He then changed pads(I think it was foam) and used a 3m product that he called a "swirl mark remover". When he was done, I could count the crab apples in the cars reflection from a nearby tree.
