First of all, it might help to give you the definition of viscosity as defined by Merriam Webster
The quality or state of being viscous.
The property of resistance to flow in a fluid or semi-fluid.
The ratio of the tangential frictional force per unit area to the velocity gradient perpendicular to the direction of flow of a liquid — called also coefficient of viscosity.
Maybe a good description to visualize is to think that honey has more viscosity than water. The honey has more viscosity than water. It's thicker and flows more slowly. With metal polish, this matters because you don't want a water like solution. It won't stick to the metal surface long enough to work on the metal. It also won't do a very good job of staying at the surface of the cloth or buffing wheel you're using to do any good.
The Quick Sheen metal polish has a creamy smooth viscosity. It's thin enough to spread on the metal surface with little effort and yet thick enough that it will not only stick and coat the metal surface, but will be able to stay on the surface of the rag or towel you're polishing with. This was the end goal and right where we wanted it. The viscosity thickness of the metal polish was one of the most difficult parts of developing our advanced metal cleaner and polisher. Getting the viscosity of the metal polish that we achieved was tested time and time again, until we found the perfect thickness for maximum results while being able to spread it out without losing the actual polishing power. The smoothness you’re looking for needs to be not too thin, nor too thick.
You'll find that a lot of other brand polishes have a very dry paste-like viscosity. This make it very hard to spread and actually work. You still need a degree of "wetness" to the polish. In order to get this wetness type of feel and in conjunction with them adding rouge to the formula, they opt to add in a petroleum based product. This petroleum based wetness is essentially a Vaseline type of jelly substance. An unfortunate side effect of using this product is what's left on the metal surface after you've applied and polished the metal polish. It's the petroleum residue left over that prompts the need for buffing.
If you start with the right viscosity to begin with, you don't need the petroleum base to hold the rouge in the formula. The viscosity matters!
The Viscosity of Metal Polish from Our Competitors
You'll find that most other polishes are thick like paste and are hard to spread around, especially without a buffer. During our intense research process, we discovered the importance of product density as it relates to how much oxidation and rust can be removed with one application. If the product is too thick, it simply can't be spread well enough to cover very much surface before drying and flaking off. This thickness also won't allow the polish to penetrate deeply enough into the problem area, therefore not truly polishing and removing the problem that caused the oxidation in the first place. In order to have any kind of effect on the surface you’re polishing, a motorized buffer is required.
On the other hand, if it's too thin the product won't be able to stay on the needed part of the surface long enough to penetrate deeply enough. It won't be able to generate any heat necessary to reach the underlying surface. Having the right viscosity is extremely important. You need to keep in mind how far it needs to spread and how deep it should be penetrating the pores of the metal. In addition, it should stay moist long enough to be able to successfully wipe it off without over "watering" down the surface you're looking to polish. It’s important to get the right shine the first time. Honestly, we hate wasting time and unnecessary work. You should be able to take care of the polish quickly, efficiently, and then be able to admire the work.
So, hopefully this helps to convince you a little bit take a second an order your set of the Quick Sheen metal polish system now.