Barry can give the definitive answer but I say no. You'll be past the recoat window you'll run the risk of de-lamination, lifting of the previous coat, all sorts of bad stuff. If you want to do it right follow what Barry wrote in "The Perfect Paint Job". It's on the last pages of the paper Tech Manual and also on the website. I will also post it here. Read it, follow it to the "T" and you will not be disappointed.
The Perfect Paint Job
March 2013
Our goal is to accomplish a paint job that has a strong foundation, maximum gloss and will last for many years. This type of painting is not practical for the everyday production body shop but it will serve you when you do your next restoration or a street rod job. We are going with the assumption that the metal or fiberglass has been stripped of all paint.
All bare metals and aluminum should have 80 grit DA scratches.
Bare metal is always best cleaned with #700-1 Waterborne Wax and Grease Remover then let it set 30-60 minutes before applying the epoxy!
After first reading our Epoxy Tech Sheet mix enough #6600 series epoxy to spray two wet coats over the entire car. Spray one wet coat and let flash about 30 minutes then apply a second wet coat. Let the epoxy set overnight then apply body filler, fiberglass filler or glazing putty over the epoxy. It is not necessary to sand the epoxy before applying the fillers (within the first 7 days of spraying epoxy) as they will bite into the epoxy and feather great. When you have finished sanding all of the bodywork you are likely to have some bare metal spots from sanding. Spray one wet coat of epoxy over all filler spots and over any bare metal spots. Now let the vehicle set overnight.
The next day you can start spraying the 2K Primer over the epoxy. Once again, it is not necessary to scuff or sand the epoxy before applying primer. The most important thing to remember at this point is spray one wet coat of primer and let it set for 10 minutes before applying the second coat. Follow this procedure between coats of 2K Primer. This step when abused messes up more paint finishes than anything else!
When all of the primer blocking and any necessary primer repairs are finished it’s always best to use the epoxy as a sealer. Mix up enough epoxy to go around the car with one wet coat and adding a double shot glass of SPI #885 Urethane Reducer per quart. Let the epoxy set for 30 minutes. Stir one more time and strain. Spray one full wet coat of epoxy over the entire car. The epoxy should set for 2 hours before spraying basecoat or the next option is let it set over night and wet sand the epoxy with 400-800 then spray the base.
Next to rushing the 2K Primer rushing the basecoat is the second cause for the final gloss and depth of a paint job to look bad. It’s very important to use the slowest urethane reducer in your basecoat that you can get away with regardless of outside temperature. Just allow enough extra time for the basecoat to flash off and dry. The difference between a very slow grade and medium grade reducer will show up in the final gloss. The slower grade reducer also has better solvency and will give you far better adhesion. Spray the first coat and let it totally dry before spraying the second coat. It’s best to wait 30-45 minutes between coats of base.
If your basecoat isn’t perfect:
After two coats of base the vehicle should set overnight then do any minor wet sanding with 800-1500 grit sandpaper to remove any orange peel or trash. Apply the next two coats with 45 minutes of flash time in between coats. Some colors will require additional coats. If this is the case, again, wait 45 minutes between coats.
Let the basecoat set overnight.
A word of caution: There are 2-4 basecoats types that cannot be sanded or you will lose adhesion so avoid those basecoats. Check with your basecoat manufacturer.
Applying Clear:
The following day tack off the vehicle then apply a wet coat of SPI Universal Clear and let the first coat of clear set 30 minutes.
Spray the second wet coat of clear and let it set 30 minutes. Let the clear set for 30 minutes before applying each additional coat as well.
Then proceed with normal wet sanding and buffing when you are ready.
Layering multiple coats of clear over multiple days:
From two days to two weeks after the job has been completed, wet sand the clear with 400-800 grit sandpaper to block out any orange peel or dirt. After wet sanding let the car set in sun for a day before remasking and degreasing then apply a wet coat of clear. Let the clear flash 30 minutes. Apply a second coat of clear, then 30 minutes later apply a third coat of clear.
Let the vehicle set two or three days in the sun to help to get all of the solvents out and settle the paint job. If any wet sanding is required before buffing sand with 1500 grit sandpaper then set the vehicle in sun for two to three hours. Bring the car back into the shop and allow it cool to room temperature then buff.
If you follow these directions you will have a durable long lasting paint job with maximum depth and gloss over a solid foundation.
Never wax a paint job applied this way for at least 90 days. This also depends on the amount of sunlight the car has been exposed to in the meantime so feel free to call for advice.
