I have to say the only thing I have experience with as far as finishing, buffing and polishing (or as I refer to as cuttin' and buffin') is automotive. I have a great respect for those who work in wood but I am NOT one of them and don't claim to have a clue when it comes to woodworking. Automotive is a different story though.
Back when I was doing more with street rods/muscle cars and drag racing it seemed like I was always doing some paint and body work on something. But that was also back when I had my old shop at my parent's farm set up as a make shift paint booth as I never really wanted to paint at my home shop in a subdivision.
Like anything it all begins with the sheetmetal and bodywork. Take a lesson from Robert over on his MP&C Shop Projects thread for inspiration. But paint and body starts at the foundation and the metal and prep work is paramount in getting a show quality job.
Let's assume the paint and clearcoat has been applied. And by applied I mean I applied it so I know how much clear is on the vehicle as this is critical because not everyone puts topcoats on the same and if you ever sand or buff through clear, your work really just began. I would consider myself a "hoser" as I apply some material.
I have also found that by over-reducing the last coat of clear by approx. 10% really helps to flatten out the clear and greatly reduces the amount of sanding to be done. Once I examine the somewhat cured clear (doesn't cure completely for about 30 days) I determine where to start. Generally between 1200 and 1500 grit for starters ending up at 2000 grit, all of this in wet/dry with a couple drops of Ivory clear in the water to assist with paper clogging. Don't focus on sanding edges as they get enough by accident also try not to cross body lines as this is an easy way to sand through the clear.
Once the clear is flat and color sanded (cut) I move on to the next step. I have a DeWalt variable speed buffer that I have used for the past 10+ years that I absolutely love. Keep in mind that when using clear coats with isocyanates you have to create some heat to kind of "flow the clear" or "move the clear" around a bit but too much and BAM, you just went through. I start out with 3M Mircofinishing Compound and a white compounding pad on the buffer. Keep the buffer moving and all you are trying to do is get rid of the sanding scratches, not necessarily making it shine, yet. Keep the pad clean of buildup by dragging a screwdriver across it occasionally.
Next up is the yellow polishing pad using 3M Finesse-It polishing compound. This will start to bring the shine and depth into focus but don't get carried away, again you are just removing the swirl marks from the previous step.
Following that is a foam pad using 3M Imperial Machine Glaze that again just removes the finest of the swirl marks from the previous step. At this point I am basically done with the machine and if all has gone well I won't have to go back and touch up any areas of finely missed sand scratches or swirl marks.
Once the vehicle has been reassembled and completed I go over it by hand with 3M Imperial Hand Glaze for that show stopping shine and depth that makes the paint still look wet.
All in all it is a LOT of work.
Mike.
