How many passes to take off a coating?

I can take Choose nanotech 9H coating out with two passes of Rupes UHS, I know it's all off because it's on an over apply area which darker than the rest. The stain coating area was there for over a year so it's completely cure. All coating that I experienced with are not that hard to remove even G-technique that claim you must sand them out.

Depends on the Coating and how long it's been on there. Have removed coatings (year old WG Uber) using M205 and orange LC Force pad w/ a Flex 3401. Currently removing a month old coating using Flex, Scholl Honey Spider Pad and Scholl S20, 4 passes with Flex. Likely a decent coating won't be removed with a finishing pad, although the jescar polish *might* remove it if with a more aggressive pad.

Only way to know for sure is to do half the hood, spray it with water and see if it acts like it has no LSP on it and even that's no guarantee it's all gone. Sometimes ya just gotta tell from the look/feel of the paint.

Generally, when I remove a coating will first do a total decon (iron remover, clay), wash with a very concentrated wash soap solution then go after it with polisher/compound. If you have a foam cannon I'll usually foam it with a 1:2 solution of Gyeon Foam, then decon, then clay, then wash, then take the machine to it.

Chances are that no matter what coating, if it's a year or two old it's gonna take a medium polish like Menz 2400 w/ orange light cutting pad but ya never know! Just gotta start trying stuff until YOU'RE convinced it's gone. Generally coatings aren't as tough as mfg claim them to be.

fightnews said:

You think you need a cutting pad and a medium cut polish to remove synergy or centurion?

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Hard to say...never ran across 'em. Generally a good starting point is a medium polish and a light cutting pad although I usually give M205 with a light cutting pad a shot because ya just never know. I'm generally of the belief that if a coating mfg claims 3-5 years durability, it's time to divide by 2 to get a real-world estimate. Their 3-5 years was likely on a test vehicle that accumulated less than 5000 'good weather' miles a year or the coated it, let it sit in their headquarters for 5 years and then said "Good as new...!"

Isn't synergy still more carnauba based than anything else even if it contains some "nano glass particles". If so you should not have an issue polishing that off with a light polish. I have no idea what centurion is.

Are you trying to correct any marring in addition to removing the coating? If not, I would still go through to complete breakdown of abrasives with Jescar polish. In my opinion, I would want to maximize gloss from the product instead of thinking just a couple section passes may remove the coating. Plus the fact I never want to underwork any DAT's. Just my opinion...

Sometimes carpro spot remover is enough to remove some coatings...and sometimes it takes 1500 grit sandpaper...
205 with MF pad should be enough for most coatings.

antti@561detailing said:

Sometimes carpro spot remover is enough to remove some coatings....

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do you mean Spotless??? If so I don't entirely agree...


Use CarPro Spotless Water Spot Remover to maintain your Cquartz coated vehicle. Even though coatings like Cquartz provide a rock-hard barrier of protection, they can still degrade due to the long-term effects of calcium building up on the surface. Regular application of CarPro Spotless Water Spot Remover will keep your Cquartz coated vehicle looking its best!

CarPro Spotless Water Spot Remover

Features:

• Advanced balanced-acid formula safely dissolves hard-water deposited mineral residues before etching can occur.

• Developed to quickly remove damaging water spots

• Compatible and safe for use on clear coat and all CQuartz Nano-Coatings when used as directed.

https://www.carpro-us.com/paint-decontamination/carpro-spotless-water-spot-remover-500ml-16-oz/


I use it on coated vehicles. To test this theory one area had a slight high spot... I scrubbed it as hard as I could with Spotless... didn't put a dent in it.
Used it on another vehicle with a coating that had some spots.. Did the hose/water test... panel reacted just like the other panels without spotless.


But to answer the OP's question, a typical polishing, 4 section passes with a good DAT polish should do the trick. Had to do it just last week when a coated vehicle had PDR... Polished out the panel after the PDR guy left, hit it with some erasure, then CQUK. Came out perfectly...

3 passes on crystal serum light with essence on rupes yellow took it off for me. Also, gtechniq crystal serum will only need sandpaper to remove if misapplied, i.e. left to cure without wiping at all.

Sent from my SM-G920V using Autogeekonline mobile app

"GTechniq Crystal Serum Light is the consumer grade version of GTechniq’s strongest coating, GTechniq Crystal Serum. GTechniq Crystal Serum is only available to GTechniq accredited detailers that have been certified to use it. In fact, if applied incorrectly, GTechniq Crystal Serum can only be removed from paint with 1,500 grit sandpaper.

GTechniq Crystal Serum Light is the consumer version of that same product – enjoy the rock-hard protection without the pressure of improper use. GTechniq Crystal Serum Light brings 80% of the professional Crystal Serum to the table."

So its NOT the "Light" that can be only removed by sandpaper. It is the the professional grade.

fightnews said:

Say you are using jescar finishing polish and a black finishing pad?

Are we talking closer to 1 pass or 7 (full cycle)?

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IMO I'd use a white pad. Black pads have no cut.

As noted earlier, you'll likely see the difference, more so on dark paint. Coated areas tend to be darker thus on my pure black, I can make one pass with a light polish and remove Cquartz or McKee's 37 coating as I've done it. very clear difference.

hoyt66 said:

"GTechniq Crystal Serum Light is the consumer grade version of GTechniq’s strongest coating, GTechniq Crystal Serum. GTechniq Crystal Serum is only available to GTechniq accredited detailers that have been certified to use it. In fact, if applied incorrectly, GTechniq Crystal Serum can only be removed from paint with 1,500 grit sandpaper.

GTechniq Crystal Serum Light is the consumer version of that same product – enjoy the rock-hard protection without the pressure of improper use. GTechniq Crystal Serum Light brings 80% of the professional Crystal Serum to the table."

So its NOT the "Light" that can be only removed by sandpaper. It is the the professional grade.

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I meant that to be more clear in my post. I did specify Crystal Serum- i.e. the pro version, in my sandpaper reference. This was to meant to correct the statement earlier in the thread that some manufacturers claim it can only be removed by sandpaper when in truth the sandpaper is only required in the case of misapplication as you have more clearly stated.

Thanks

The fact is that you'll never be completely sure that you removed 100% of the old, cured coating unless you sand it. Especially if the coating to be removed is the new breed of top notch coatings, where the coating adhesion to the clearcoat is almost like a fusion to it.
If you fail to remove it completely before recoating it, you can run into problems like water spots type of marks, that can be seen from a 30 to 60 degree angles, behing the recoated surface, as mentioned is some threads here at AGO.
I always try, before getting into sanding, the combination of rotary, wool and Menz 300, as the last resort of removing it.
It's crucial asking what type of coating was applied in beforehand, and if the answer is CSL, CS, CQ Finest, Modesta, Opti Coat Pro Plus or any coating that was applied by an accredited detailer, I would sand it just to be sure. And properly charge for it.
Let's say that it is the collateral effect of going in that route, semi-permanent, strong adhesion coatings.
Bsst regards.

^^^ If this is the case and even the best coatings need to be replaced every 2-3 years, that seems like a lot of sanding for the lifetime of car and an lot of additional effort or expense. You'll never know how much clear is coming off when you said. If you use 2000 or higher your're probably not removing much. But that still seems like a lot of sanding on the paint.