Clay is used in conjunction with other steps to remove above bonded contaminants. It creates, smoothness. Smoothness leads to gloss.
There are many different options to clay such as, actual clay bars, nanoskin or like-kind clay mitts, or even clay disks for a DA.
The main reason why many folks opt for clay mitts over actual clay is due to it's ease of use, speed and maintenance. A typical Nano-Skin can last up to 50 vehicles, With regular clay you need to "need" the clay often, which is time consuming. With a clay mitt no needing is required, just frequent rinsing off.
If you drop a bar of clay, it's done... you need to throw it away. With a clay mitt, just rinse it off.... I can say from experience that it's very easy to drop a piece of clay...
For clay lube, you can make it yourself, but here is where the phrase "it depends" comes into play. QD's are costly, and while they have good lubricity they're designed to offer some protection with built in waxes or sealants. Dedicated clay-lube is costly... In comes, McKee's N914 rinsless wash solution, with dilution formulas specific for making a clay lube. My preference is to use the latter, and mix a 5 GAL from the concentrate at the recommended dilution. It's cost effective, when my spray bottles are running low, they get refilled from the 5 Gal container, it offers excellent lubricity. So I have a waterless wash solution, which can double as a QD, which can tripple as a clay lube. Oh, and N914 can be used as a good interior wipe-down product too. So from a cost effective, multi-purpose use, it's the best option IMO.
Be sure to check out the How To's section to see Mike Phillips video's on how to clay.
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