Just to chime in...
This question comes up very often on discussion forums for a good reason and if you've ever had a car re-painted or even just a panel they you can relate because you know the cost involved and the little things like how you have to drive a different car or get rides while your car is getting painted, not a hassle for everyone but it is an interruption in your life unless you're working on a project car and already planned for the paint job.
My friend and an engineer, which is just my way of saying he's a man that is thorough in his research and analysis, researched all or most of the major automotive paint manufactures to find out what "they" recommend for "their" paint systems for a waiting time to "seal" the paint after it is sprayed. All paint manufactures recommend waiting at least 30 days air-cure before sealing the paint and some recommend up to 60 to 90 days to wait before sealing the paint. For those of you that have been in the detailing forum world for any length of time will know this forum member as Paul aka the other pc
That all said, most painters recommend waiting at least 30 days before sealing the paint but there are numerous stories of people sealing the paint before 30 days and experiencing no problems.
My question is always... what's the hurry?
Sure some people need to pick up their car from the body shop and put it back into service that day. Even so, modern clear coats are pretty touch compared to paint technology just 30 years ago. Also consider, ANYTHING corrosive enough to harm a modern clear coat finish is strong enough to obliterate a micron or even sub-micron thin layer of protection of any coating of wax or paint sealant. So if something lands on your fresh paint or your original paint, if it's corrosive enough to eat into and etch the paint it's going to do it whether you seal it with wax or paint sealant anyways.
Most waxes and paint sealants can only slow down the corrosive effect of harmful substances that land on your car's paint, not stop it in its tracks.
There's a lot of confusion over "Waxes" and "Paint Sealant" but they both fall into the same category of products and that's "Paint Protection Products", that is you apply them with the hope they will leave behind a layer of protection on the surface of your car's paint to protect it AND also make the paint look good.
(That's the reason right? Anyone want to post their opinion as to why we wax or paint sealant our car's paint?)
Fresh paint outgasses, that is the solvents and other ingredients work their way off the paint and the idea behind not "sealing" the paint is to not hinder the outgassing process.
Now I always read someone on some forum posting that the paint is catalyzed and hardened and by the time you pick up your car from the body shop the paint is fully cured and and safe to wax. People will also say the paint was heat baked at the body shop and the same thing, paint is fully cured and and safe to wax.
I asked the head chemist at Meguiar's about this and he laughed at these types of comments and in his normal way of making the complex very simple to understand he said,
"Mike, if you have your car painted or just a fender painted at a body shop and then take the car home, park it in your garage, close the garage door and go inside and watch a football game, and then come back out to the garage after a few hours... what do you smell in the garage?"
My answer was
"Fresh paint?"
And he said
"yes"
Now if you're smelling anything related to the fresh paint in your garage what do you think you're actually smelling? My guess would be one of the solvents used to thin the paint so it can be sprayed evaporating off the paint. Just a guess. And that would actually be some type of molecule
floating in the air, that came off the paint
going into your nose.
Now if you repeat the above and don't smell anything in your garage than that's probably a pretty good sing nothing or very little is still outgassing BUT the idea behind paint manufactures recommending that you wait at least 30 days before "Sealing" the paint is to provide a "Window of time" for the paint to fully outgass, dry and harden before you seal the surface.
The paint might be fully outgassed, dried and hardened one day after it was sprayed, 3 days after it was sprayed, 17 days after it was sprayed or 29 days after it was sprayed, but since there's no quick, simple and easy way for the average car owner to test and confirm this point in time, a General Rule of Thumb is to wait for 30 days before sealing the paint.
Make sense?
So seal your fresh paint with a wax or paint sealant right there at the body shop after you pay your bill or drive your car home and do it there or wait 30 days, you have the power in your hand to make that decision.
I also wrote a rather long explanation on this topic back in 2004 because the topic comes up so often...
Paint Needs to Breathe
rops: