Well, just my -0.02$
I've run through many bottles of Pinnacle Black Label Diamond Surface Coating that is the product I most apply here.
I had a batch of empty bottles that I did the following:
a) Passed all last '~0.01oz' of each bottle to one bottle, emptied the sprayers and I could join a considerable amount of product that I use to coat door jambs as freebie.
b) (this is where things became interesting to your question):
After procedure above, I've filled one of those (now empty) bottles with filtered water (almost full). I've closed the lid and 'shook like an animal'.
I've then passed the water from this bottle to another one, shook (is it right verb!? kkkkkk) and did it again, passing through 4 bottles. The water fastly switched from clear color to gray translucent color.
The last bottle I've labeled as watered down, and tested it out.
Test subject was my dad's car, which I call my 'riding test panel' hehe.
Results were above expectancies, since the product spread slick as the coating booster, and let me tell you I was really surprised with water beading it exhibited specially on glass.
I now use the mixture as an after wash to my own car / dad's car.
Cons of this: (now, the bad part).
Would I ever apply this to a customer's car?
Never, Ever. Even though it 'worked' in my test scenario, I cannot rely on this diluted product to name my work.
That said, I even wouldn't mix the coatings (full strength) I have with water because I cannot control what I'm creating, thus cannot warranty protection I'm selling to customers. If I mix, I won't be confident it's a good product worth someone paying for me to apply.
I won't either dilute it with IPA, again, can't control the outcome and I'd never trust it enough to apply to a customer.
My thoughts above are to show you can try diluting the coating and you can even achieve good results with it, but I can't recommend the practice since you won't be able to be honest with customer regarding estimated durability, and trustable protection. I don't like this feeling.
If it's only your money, your car, your coating, you're bored and willing to do something nasty, go on and be happy! Start testing on underparts of bumpers or even test subjects (my 'portable shaving mirror' is fully coated with many layers of wheel coating)...
I do my tests to know better products I'm using, and if your test can give you any insight towards improving your work, it's worth the spent product/$$, even if you then flush the wastage.
In example, see this simple test I've conducted last year. The long term observations I got from it helped me much regarding application of coatings.
http://www.autogeekonline.net/forum...g-pbl-coating-macro-microscopically-more.html
**Another simple example that explain my point of view: I've tested applying coating with and without proper surface preparation (cleansing polish, IPA, hyper-wash, you name it). Both worked (on time, not talking about long-term).
Even knowing improperly prepped surface could potentially work, I extrapolate the results of this test to the following:
If my prep goes 99.9% instead of 100% I seek, that's OK!
The bad interpretation would be: I won't prep because of my results above.
Got it?
Hope that helps.
Kind Regards.