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Many manufacturers claim that their car covers are 100% waterproof. Really?... Even the ones that are constructed of cotton and wool? It would seem so according to the salesmen and the brochures. Let's put it to the test using my coats.
The Woolen Overcoat
Now, I can (and do) look and act stupid most of the time...but not all of the time. I know that when I'm being rained on. my coat gets heavier. It acts like a sponge not a water repellant. Not only that, it holds the water and if left unattended mould and mildew will build up.
So lets remove the '100% Waterproof' natural fibre car covers from the list. They are not waterproof!
The PlasticMac
Now, lets look at the man-made materials. Plastic! That's waterproof, isn't it? I have another coat, a plastic-mac kind of thing that keeps the rain off me when it's raining. 100% waterproof? Well, yes.... and no. It keeps the rain off me but after wearing it for a while I kinda get sweaty. You see, not only does it keep the rain and moisture out, it also keeps the moisture in. So, while I'm walking, generating heat and thus hot air between me and the coat, it condenses and turns to moisture on the inside of the coat not letting it escape. The same thing will happen to your car if you use a plastic car cover. Yes, plastic is 100% waterproof.... but both ways. Not good for preserving your car. Remember the mould and mildew...it'll eat your paintwork.
The Great Outdoor Breathable Coat
1978...W.L. Gore invented Gore-Tex. I could go into the science of it all here, mentionning surface energy, surface tension, microns and pores per square inch or metre but basically all you need to know is that this man-made fibre has microscopic holes in it that big waterdrops can't penetrate while small water vapour moisture drops can. Meaning big raindrops on the out side stay out and tiny moisture drops on the inside, created by you, can escape, thus keeping you dry.
Your waterproof car cover doesn't have to be Gore-Tex. There are many variants out there today but they all work on this principle.
So this is the nearest thing you can get to a 100% waterproof car cover. (The 100% waterproof car cover does not exist).
Bear these snippets of information in mind when you are trying to choose which waterproof car cover is best for your car. Whether you are storing it indoors or outdoors (Yes! Moisture can and will occur when a car is stored indoors) you'll want to look at breathable waterproof car covers. Not plastic and definitely not fabric.
Strange how my coats have other uses!
