Hi StLB5,
Here is a copy of the reply of Mike Phillips to the same exact question. Hope this will answer your question.
---------------------below is the response of Mike--------------------
Now about #20 Polymer Sealant and Can you Layer it?
Your question is a good one and a question I am currently writing a response to for another purpose.
That said, let's start by defining the word "Layer".
1. If by the word “Layer� we mean applying multiple coats of a product in an effort to insure there is a uniform layer of protection equally distributed over the entire surface, then yes you can "Layer" #20 Polymer Sealant.
To do this you would want to apply two thin coats, and perhaps a third coat after 24 hours has passed. The reason you want to wait for 24 hours is that it can take up to 24 hours for the polymers to fully Set-Up. (This does not mean however, to leave the wax on for 24 hours before removing)
This would provide the maximum amount of material i.e. polymers that you could possibly hope to bond, or cross-link to the surface.
2. If by the word "Layer" we mean applying multiple coats of a product in an effort to build up a "measurable film-build" whereby each additional coating increases the "thickness" of the previously applied coatings, then the answer is no.
There are exceptions. For example, there was a product out about 10 years ago called, “Touchless�. This product was more akin to applying a layer of clear paint, than it was akin to applying a wax.
I don’t remember ever seeing or hearing anyone who experienced good results, or at least the kind of results they were hoping for after using this product. I do remember seeing products/systems developed to remove this product because of unhappy customers.
If we just look at the big picture for a moment, maybe this will be easier to understand,
First of all, if you apply the worlds best wax to a car and then park it outside for 1 week, in that amount of time, chances are very good, that some type of contaminant will have landed and bonded to the horizontal surfaces.
Does everyone agree?
(I’m not saying the above is what you do, I’m just speaking in general terms for purpose of example. i.e. it's not only possible a contaminant could bond to the surface in a week of outside exposure , it’s also highly likely.)
This being true; then to restore the finish you would first wash the car, then clay the car and then re-apply your favorite wax.
Does this sound correct?
If we agree so far, lets take it a little further.
While a premium car wax does provide protection, it's still not an “invisible force field�, that will prevent the detrimental elements and substances that a car's finish is exposed to during day-in, day-out normal use from coming into direct contact with the paint.
This being true, then the most we can hope for is a wax that will take the brunt of the damaging effects caused by exposure to the environment while at the same time limiting any potential damage to the best of its ability.
Sacrificial Barrier
The primary purpose of a wax is to form a layer over the surface, which acts as a “Sacrificial Barrier�.
That is, the wax “sacrifices itself�, so your finish doesn’t have to.
Now, if this true, then you want the wax to “wear off�, as a natural part of the protection process, thus protecting your paint by giving itself up, whereby you then can the replace this sacrificed wax with another coating the next time you wash and wax your car.
In a perfect world, or in a Museum, (Maybe GeekySteve can add to this), once you've applied a coat of wax to the finish, it would never come under attack, it would never wear off, and your finish would always look new. In a world like this, you wouldn't need to apply multiple coats of a product that builds-up for protection.
If the product you’re applying truly does build-up, then you would slowly decrease the clarity of your finish because to my knowledge, nothing on the market that claims to be Layerable, is “Clear�.
That is, it’s not clear in the bottle, and it’s not clear when you pour some out onto your finish or onto a wax applicator.
If it’s not clear to start with… how can it make the surface it’s applied to more clear?
Answer: It cannot.
Conversely, if it’s not decreasing the clarity, this then begs the question… Is it really layering?
At least by the second definition I listed above?
Or is the layering taking place more akin the first definition I listed?
The only thing I can think of that truly builds a measurable film on the surface and does not decrease its clarity is… more clear paint. (most clear paints I have seen by the way are not entirely clear, but more of an amber color).
Conclusion:
If your car is garage-kept, never driven in inclement weather, and so on and so on, then,
A. You don’t need to build-up a layer or film-build or wax. (That’s assuming it can be done in the first place)
B. Your finish will probably look better with an application of a Pure Polish, like either #7 Show Car Glaze, or #81 Hand Polish.
Neither of these two products contain any wax, polymers or silicones and offer no long lasting durability features. They are solely for making paint look good. And if your car is a truly a garage queen, then you really don’t need a protection product, you want a product that creates beauty.
By the way, the above scenario does NOT apply to about 90% of the population, (or more).
If your car is a daily driver, parked outside and exposed to frequent washing and/or inclement weather, then,
A. You need to apply a protective wax to your finish to act as a sacrificial barrier.
B. As this wax wears off, (as you want it to, i.e. it’s giving itself up so your paint doesn’t have to), you want to be able to,
* Clay and/or Clean the paint (remove defects, prepare the paint for polish and wax)
* Polish the paint to restore its maximum gloss and clarity
* Protect the paint by re-applying the sacrificial barrier.
Unless your car is displayed in a Museum, maintaining a car’s finish is a process.
It requires multiple dedicated products that make up a multi-step system
or,
It requires a premium quality one-step product like a like Meguiar’s Cleaner/Wax which includes a cleaner, polish and wax... i.e. an all-in-one.
Buying into the idea that you can somehow build-up multiple layers, (i.e. a [measurable thickness), of a product is not only undesirable, but also... junk science.
Your opinion may vary of course. (and that is the purpose of a forum like this is to share opinions.)
I use Meguiar’s' products because I get professional and consistent results every time.
When working on a customers car this is important because I don't have time to do it twice, and I don't have the pocket book to buy them a new paint job if a mistake is made.
When working on my own cars, it's important to me to use top quality products like Meguiar's because... well because it's important to me...
Mike