M21 Synthetic Sealant - Multiple Coats?

[RSnider]

After rotary polishing my car with UC and painstakingly slow tool and arm speeds, I have a largely hologram-free finish. Not wanting to chance instilling holograms at this point by applying M21 with the rotary, I applied the first coat by hand.

My first question is, is there a benefit to applying multiple layers of M21? If so, what is recommended? The car isn't driven often, so it can afford to sit for several days as the coats are applied. It does, however, get driven in the weather occasionally, so I would like the added protection of multiple coats if there are any.

Second, I read somewhere on the Meguiar's forums that a freshly fully-cured coat of M21 will actually stand up to quite a bit of wet sanding before breaking down. Not that anyone would apply M21 and then immediately proceed to wet sand the finish - it was more of example scenario. So my question is, can the subsequent coats of M21 be applied with the rotary without instilling holograms in the clear coat?

[wifpd4]

Re: M21 Synthetic Sealant - Multiple Coats?

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Second, I read somewhere on the Meguiar's forums that a freshly fully-cured coat of M21 will actually stand up to quite a bit of wet sanding before breaking down. Not that anyone would apply M21 and then immediately proceed to wet sand the finish - it was more of example scenario. So my question is, can the subsequent coats of M21 be applied with the rotary without instilling holograms in the clear coat?

This seems unlikely. If you happen to find this reference, please post the link. I would like to read that discussion. Thanks.

[Michael Stoops]

Re: M21 Synthetic Sealant - Multiple Coats?

My first question is, is there a benefit to applying multiple layers of M21? If so, what is recommended? The car isn't driven often, so it can afford to sit for several days as the coats are applied. It does, however, get driven in the weather occasionally, so I would like the added protection of multiple coats if there are any.

We recommend applying two coats just to ensure uniform coverage and appearance. When properly applied, any wax/sealant should go on very thin so it can be easy to miss a spot or two, especially on lighter colors. Beyond that, however, you're just using up product without gaining anything.

Second, I read somewhere on the Meguiar's forums that a freshly fully-cured coat of M21 will actually stand up to quite a bit of wet sanding before breaking down. Not that anyone would apply M21 and then immediately proceed to wet sand the finish - it was more of example scenario. So my question is, can the subsequent coats of M21 be applied with the rotary without instilling holograms in the clear coat?

Not sure how these two are related but we'll address both anyway.

The comment regarding wet sanding and the presence of durable polymers isn't quite what you're suggesting here. A freshly applied durable polymer (and that even includes Ultimate Quik Wax spray) can impede the ability of a sanding disc to start cutting. That's quite a bit different than "M21 will actually stand up to quite a bit of wet sanding before breaking down". Where sanding media will immediately start cutting into truly naked paint, the presence of a durable polymer will noticeably slow down that initial cut and make the paint look more hazed at first than really sanded. Basically, you don't get the level of initial cut you'd otherwise expect so you start thinking you need to change tool speed, pressure, or something. It's a bit of a puzzling experience the first time around as one doesn't normally think of a wax or sealant being "strong" enough to withstand sanding. They aren't, but they can slow down the initial bite.

As for applying M21 via rotary without creating holograms - that's up to your pad choice, your skill level, and the way the paint responds. In theory, yes you can do it. We'd suggest a W9207 Soft Buff 2.0 finishing pad, the slowest speed your rotary offers, and keep that pad flat against the paint.