For those of you that have older model Evo's, I'm sure you know all about the clear coat issues on the rear wing. I have an '03 Weightless White version that I purchased brand new in March of '04. I wash and wax it regularly but a couple of years ago the rear wing developed a small hole in the clear coat. It steadily progressed into a area larger than a silver dollar with some other areas developing on the leading edge. So I finally decided that I needed to re-finish the wing. I had read a wing re-finishing guide over on evoM and even though it was good write-up there are a lot of gaps. This guide uses what I learned from that and is a more complete version.
Tools you will need:
10 mm socket
blue painters masking tape
3M double sided tape
lint free cloths
320 grit wet/dry sandpaper (at least 15 block sander sheets)
600 grit wet/dry sandpaper (2 to 3 block sander sheets)
800 grit wet/dry sandpaper (2 to 3 block sander sheets)
1500 grit wet/dry sandpaper (1 to 2 block sander sheets)
2000 grit wet/dry sandpaper (1 to 2 block sander sheets)
1 gallon bucket
DuPont clearcoat (DUP.A-7480A) - available at www.paintworldinc.com
Meguiar's #7 polishing compound (if necessary)
Turtle Wax Bug and Tar remover
Orbital buffer (helps but is not necessary)
*Note on tools, the initial sanding process may go a lot quicker if you have an orbital sander that takes pucks
Step 1: remove the wing!
I found it a lot easier to work on the wing by removing it. Take your 10 mm socket and unbolt the wing from the trunk. It's also held on by 3M double sided tape and a plastic rivet so take your time working it. It helps to have a friend working the other side so that you can cleanly take it off. Once you take the wing off, there will be tape residue. Saturate the tape over night with the Bug and Tar remover and then work off the tape with a clean towel. If it doesn't all come off the first try, re-saturate it and let it sit again. At this step, you can choose to leave the metal receptacle for the pop rivet or take it out.
Step 2: Sanding
Prior to sanding, it's a good idea to tape up the end plates from the main plane of the wing. That way you won't knick the inside plane while sanding or the bottom corners when handling it. This is a very critical step because your time and energy here will directly effect the end result!!!! Just to give you an idea, I spent 4 to 5 hours sanding down to the carbon. If the damage to the clearcoat is not very severe, you won't have to go as far. Regardless, you want a uniform surface to clear coat.
Start with the 320 grit paper in the sanding block to remove any remaining clear coat. Make sure you have your 1 gallon bucket handy to keep your sand paper wet as well as the area you're sanding. When you start sanding, the water will turn milky white, keep going until the water starts to turn black. That tells you have removed all of the clear coat. Also, keep some old towels handy so that you can periodically wipe the wing down to see where you are at. You probably don't want to use your spouse's best bath towels for this!
Once you've sanded off the clear coat make a visual inspection, look at it from different light angles and different perspectives. If you are happy you have a uniform surface then wet sand with the 600 grit paper.
Step 3: Time for clear coat
Prior to actually applying the clear coat, wipe down the plane of the wing with acetone with a lint free cloth to remove any dirt or oil your hands may have transferred. This will eliminate the "fish eye" effect that oils cause. Now take your can of clear coat and put it in warm water for 10 minutes, this increases the can pressure so that it will apply a smoother coat. This is also the time to make sure your painting space is prepped. I applied the clear coat in my garage although a paint booth would be best. I vacuumed the garage floor and then wet it down with water to keep the dust at a minimum.
Put on your respirator, it's go time! This stuff is nasty, so you'll be glad you have the respirator. Start by applying a light coat, using even back and forth strokes. Allow it dry for 10 minutes. Repeat this step 6 to 7 more times, the final two coats can be a little heavier to give it that wet look. Make sure you do a good visual inspection after each coat, even with all the prep work, I still found a dog hair after the third coat. I was able to remove it by lifting it out with a pin while it was still wet and then hit with a shot of clear. I couldn't tell where it was at by the next coat so crisis averted.
Step 4: Drying
The wing itself should be dry to the touch after a couple of hours so the threat of dust or hair is over. For acrylic clear, it takes 30 days to officially "cure" if you don't have a way to bake it, 45 days if you're in a cooler climate. During this time the clear is hardening and leetching out the chemicals in it, if you did a good job applying it, you won't have to worry about the orange peel effect and you'll have a nice smooth finish. If you do get some orange peel or you have some visible dust, at the end of 30 days get out your 800 grit sandpaper. I wasn't nearly that patient so I started in after two weeks of dry time. The 800 grit will remove orange peel and dust. Don't be alarmed that you are dulling the finish! When you're done with the 800, use the 1500 to smooth out any scratches left and then move to the 2000 grit to give it that glass finish. There is still going to be some scratches or swirl marks so this where the Meguiar's #7 comes in. Work the surface with the Meguiars on a cloth then move to an applicator sponge. The orbital buffer really comes in handy at this stage. If you're happy with the finish then you can go ahead and apply several coats of your favorite wax.
In harsh light you can still some scratch marks in the carbon so I'll probably have to do some more buffing but for the most part I'm pretty happy with the results. If you have any questions or comments, let me know! One last thing, I could probably talked into to doing this again if you're not feeling up to all of this work!
After all of this work, you should have an end result that looks like this: