Paint Needs to Breathe

[Mike Phillips]

Paint Needs to Breathe

Words mean things, just ask any Lawyer. Floating around on the Internet, and discussed for decades among car enthusiasts is the myth that paint needs to breathe.

Or is it a myth?

It depends on how literal you read into the words. If you apply the common definition used for the word breath, then "No", paint does not need to breathe. If however you take a moment to understand the idea that is being expressed with this word, then I think you'll understand why the word breathe is used when someone says, or posts to the Internet that "Paint needs to breathe".

The below is just my guestimation as to the story behind the theory or myth that paint needs to breathe. I may be wrong, but my years of working with both painters, detailers and serious car enthusiasts as well as teaching detailing classes makes me think that if I'm not dead on, I'm at least in the ball park. With that said, here my explanation of how the saying, "Paint needs to breathe" originated.

For the last 50 or so years, when a person would have their car painted, upon retrieving it from the painter, the painter would typically recommend that the owner wait for a period of time before applying a coat of wax or some type of paint sealant that seals the paint. The normal period of time that most painters recommend is anywhere from 30 to 60 days and sometimes longer, depending upon the painter. The reason for this waiting period is to allow the different solvents and other additives enough time to fully evaporate out of and off of the surface.

Wax and/or paint sealants, whether natural or synthetic, or a blend of both of these ingredients, seals the paint by coating over the surface and filling into any microscopic surface imperfections creating a barrier coating over the surface. This blocks, or inhibits these solvents from escaping through evaporation, or outgassing. Solvents also called thinners and reducers are used to thin the paint down so that it can be atomized into a spray when applied with a paint gun using compressed air.

When a customer arrives at a body shop or a dealership to pick up their car with its freshly applied paint, most painters will tell the customer to wait a certain number of days before applying wax, or paint sealant over their new paint job. If the customer agrees, then that's probably as far as the discussion goes.

If the customer asks further questions as to why they must wait before applying a protective coating to their investment, then it is my belief that most painters would do their best to explain to the customer, in easy to understand terminology, so that the customer will understand and comply with his request. This is where I think the saying, paint needs to breathe, originated.

I don't think most painters would try to explain that the solvents need to outgas in order for the paint to fully dry and harden, instead, I think they would use a more simple approach and merely tell the customer that their new paint needs to breathe.

The above fictional analogy is probably as accurate as any assumption as to how the theory that paint needs to breath was started. (I'm open to other theories however.)

People that understand the painting process understand that paint doesn't literally need to breathe; they do understand that fresh paint needs to outgas. This means that for a period of time, the solvents and other carrying agents, which are used to dilute paint to a thin viscosity so that it can be sprayed out of a pressurized air sprayer, need to work their way out of the paint through the evaporation process, also referred to as outgassing.

Read the below two scenarios and then decide for yourself, which scenario sounds more plausible.


In an effort to explain to their customers why paint manufactures recommend waiting for at least 30 days to pass before applying a coating of wax or a paint sealant, the painter can,

• 1. Try to explain the outgassing process over and over again throughout their career.
  2. Use a simple analogy that the average person can understand without challenging the painter's judgment or expertise.

My personal guess is the second option.

If the simple analogy works, it will accomplish the painter's goal and allow the painter to get back to work, not spend his time explaining the painting process to each customer as they pick up their car. The goal of course is to prevent the customer from sealing the paint with some type of wax or paint sealant until the paint has completely dried and the out-gassing process is completely over.

• * Paint does not need to breathe in the literal sense that you and I need to breathe as living human beings.
  * Paint does need to breathe in the sense that fresh paint needs to outgas.

Of course, in the last 50 years or so since World War II ended and the car crazy culture really revved up in America, (no pun intended), the result has been explosive growth in the collision repair and custom painting industries. It should be no surprise that the idea that paint needs to breathe has finally reached enough of a critical mass as to be the topic of discussion on numerous discussion forums as well as anywhere a couple of car enthusiasts gather to talk shop.

Depending on how literal you want to read into it, when someone states "Paint needs to breathe", what they probably mean is that fresh paint needs to outgas, they probably just don't know, or understand the term outgas, and/or they are confused like many people who have gone before them and are operating under the wrong idea innocently.

A different, but related version of the above would be someone that applies the same idea that paint needs to breathe to the paint on a brand new car which is also false unless the new car has been painted within the last 30 to 90 days. Sometimes during shipping from the assembly plant to the dealership show room floor, new vehicles are damaged and need repair including repainting. If all the paint on the car is the factory original paint, then it was baked on at the factory as it traveled down the assembly line and was completely cured before it left the assembly plant and it is perfectly safe to apply a coating of wax or a paint sealant of some type. If the car has been repainted due to damage during transit, then the areas with fresh paint should not be sealed with wax until the recommended waiting period has passed.

Well, this is my stab at the "Paint needs to breathe theory".

[Totoland Mach]

Great stuff Mike! I liked to use the expression "Paint needs to cure" when I used to custom paint bikes. Most folks readily grasp that terminology and will adhere to the recommendations of the painter.

Outgassing really is a curing process.

[RamAirV1]

Of course it is still OK to use #80 with it's paintable polymer on new paint, isn't it?

RamAirV1

[gb387]

Nice article... If you were to wax/seal a fresh coat of paint what would happen? Would the paint not cure? Has Meguiars R&D ever tried it when creating new products?

[Marc08EX]

Nice information Mike!

[Marc Wong]

Great article Mike. But I think the term "pain needs to breath" is no longer being used a layman's terminology. (Not over here that is.) I'd go directly with “ curing time� and that does the work. If asked any further, then I’ll go into detail of thinner/solvents having to flash off etc. It helps a lot If the client learned something new/more. Anyhow, paint DOES need to breath.


Marc.

BTW Mike, re-tried the clay bar on the windscreen, worked fine, but now its back again. *sigh*

[TOGWT]

Thank you for the information and your insights…/

We can all 'breathe' easier now

[Don]

Sounds like a reasonable theory. When people ask me, I tell them that it's because the solvents that make the paint sprayable have to fully evaporate before the paint can be waxed

[Newport Viper]

Thanks for taking the time to explain that!

[Mike Phillips]

Originally posted by RamAirV1
Of course it is still OK to use #80 with it's paintable polymer on new paint, isn't it?

RamAirV1

Yes. M80 Speed Glaze contains a protective paintable polymer and is completely safe for use on fresh paint.