Paint drying/curing time?

Compudaro

Hi guys,

Dealer got rid of a scratch from the back of my other half's car and we collected it yesterday. Just wondering how long to leave the paint before washing/waxing/polishing?

Thanks.

Owen

It depends on the type of technique used. Generally 24 hours is enough. The stuff I use is actually dry to touch in about 20 minutes, but I still recommend not washing it until a day has passed so it can cure fully.

If you're washing it with a power washer, be gentle with the area just painted, just in case.

peasant

PaintDoctor wrote: »

Generally 24 hours is enough.

It's still pretty cold outside ...wouldn't it be better to give it few days to fully harden through before polishing/waxing ?

Owen

Not at all, should be fine. It's not winter, besides, it would have already had curing time in the bodyshop's oven wherever the Dealer sent it off to to be painted.

TomMc

Wash it with luke warm water and gentle shampoo mix, using a sheepskin mitt and hose down for the first few weeks and only use a pressure washer after a month or so. Nothing heavy handed. Despite what others may tell you oven baked paint doesn't cure or harden there and then, as it is baked at much lower temperatures in a bodyshop than it is when applied at the factory to a bare bodyshell without plastic and rubber trim fitted. On a respray it can take a few months to cure and harden 100%. In the meantime you do not want to use any silicone based polishes or waxes (most are) which can interfere with the process or clog paint pores. Use a bodyshop approved polish or glaze (silicone-free) if you really must, avoid applying anything else if you do not know for sure what it contains.

Owen

TomMc wrote: »

Despite what others may tell you oven baked paint doesn't cure or harden there and then

Sorry, that's just not true. I can machine polish cars 30 minutes after I've applied lacquer. As for it taking months for paint to fully cure, how do the boys in Overhaulin do it then when they're wet sanding and machine polishing cars only a few hours after paint?

The technology and chemicals used in lacquering are much more advanced now, and literally under infrared lamps with the correct hardener, it's possible to have 495 HB Body lacquer dry in under 10 minutes.

TomMc

Just because it is dry to the touch doesn't mean it has hardened fully. When refinishers are sanding or polishing fresh paint, they are aware that it is softer initially (hasn't reached maximum hardness), but that helps them to correct defects that little bit easier. They are skilled at colour-sanding or machine polishing. They also use polishes which contain no wax or silicone and which will not interfere with paint hardening further to its maximum potential after they are finished.

The average Joe power washing a car or applying silicone based products isn't the same. A bull in a china shop approach compared with the more controlled and methodical approach above.

Owen

TomMc wrote: »

Just because it is dry to the touch doesn't mean it has hardened fully.

Which is why I recommended leaving it for a day. It'll already have had time in the workshop to dry, time sitting at the Dealers, and one more day will make it hard enough to wash.

I've pressure washed cars I've painted the same day, no ill effects.

Compudaro

So taking both arguments into consideration,would a pressure washer be okay after a week?

TomMc

PD is missing my point. Just because paint is dry and has had time to cure or harden for a few days, I'm not saying it cannot be washed. It can but you need to be gentle doing same. Why power wash fresh paint if a garden hose will do. After all, you are just rinsing off suds, not pounding off the dirt. As the paint continues to harden even more for some time after a respray, why do anything which would compromise that process.

At the end of the day the quality of the respray will dictate what you can and cannot do. A power wash on a poor respray might create problems straight away (paint lifting or peeling), especially if the panels were taped up at the edges when resprayed. On an average job it may take a few weeks for problems to arise. On a top job, nothing may ever happen, even with a powerful pressure washer. It is just that there is no way of knowing (visually) how well the paint has bonded to the panel or the original paint layers underneath, so better to error on the side of caution.