Free Shipping over $149 w/coupon DIFree | 2,900+ Products | 95 Brands | 12,000+ Reviews | 1,850+ Detailing Articles
Close Menu
Clean ⋅ Shine ⋅ Protect
Cookies are disabled in your web browser. To shop with Detailed Image, please turn cookies on and then refresh the page.

Initial Impressions & Application: Gtechniq Crystal Serum Light (CSL)


I was recently asked by Detailed Image to review a coating and jumped at the opportunity considering I have never tried the Gtechniq line of products.  This Crystal Serum Light (CSL) is a “light” version of the professional only Crystal Serum.  According to Gtechniq, CSL offers 80% of the performance of the Crystal Serum.

The durability should be 3-5 years and CSL does well at resisting swirl marks, adding gloss and keeping the paint clean.  As you can imagine, I’m unable to test all those characteristics within only a few weeks of testing, so this article will mimic my recent “application and review” articles of other coatings (22ple VX3, CQuartz and Gloss-Coat).

Initial observations were that the packaging is very clean and informative.  The box is white with grey with red writing and accents, making it very appealing to the eye as well as easy to read.  The box contains information on the product, instructions and benefits.  All are clearly outlined and to the point, so it eliminates guesswork for the installer.



Inside the box are quite a few, very helpful things.  The bottle, dropped/pipette, applicator pad, gloves, instruction/info sheet and a GTechniq sticker.  The master instruction sheet contains information for their other products as well as detailed instructions for the CSL application.


I went straight to the application on a test panel we have at the shop (I did this on a section that’s still in decent shape, away from where we shot at it with a BB gun to test how much PPF/clear bra protects the paint).  Since I was doing only about 1 sf area, I only filled about half the dropper and applied to the applicator pad (instructions say to apply 2 full measures from the dropper, but that’s for doing an actual panel)…




It went on very easily and was smooth to apply.  I applied it liberally but not dripping wet.  Next I wanted to wait and see at roughly what time the coating should be removed.  The instructions say to apply to “a small panel or 1/2 a large panel” then remove residue with a microfiber cloth.  Based on my findings on two test panels, that would go by too quick and you may be removing uncured coating, but that’s just my opinion.  The temperature at the shop was 65-70 and no humidity at all, so obviously your times may vary based on that.  Below I’m showing photos of the coated section at 30-60 second intervals to show how it looks as it dries…

At ~2 minutes, it was still very wet but showed clearer signs of the applicator strokes…


At ~3 minutes the strokes became even more apparent and small sections started to show up as dry…


At ~4 minutes it started drying a lot more and showing up as “sweating”, very similar to the CQuartz coating…


At ~5 minutes the small beads became more apparent as the area around them dried even more…


At ~6 minutes a lot of the applied coating seemed to be dry and even the small beads were starting to dry, so I decided to wipe a section at this point.  It wiped off effortlessly and there was no streaking left behind.  It simply took a couple of back/forth wipes with a clean towel and the residue came right off.


Based on that, I decided to wait even longer.  At ~7 minutes the coating looked just a bit more dry than 6 minutes…


At ~7.5 minutes pretty much all the beads were becoming dry specs on the paint…


At ~8 minutes I decided to remove some more of the residue and this time it was a bit grabby.  This left a few streaks (if you look to the left of the light reflection it’s easily noticeable when compared to the right).  These streaks came out fairly easily with a few light wipes of the section, but I left them in order to show it in the photo below.



About 30 seconds later (about 8.5 minutes overall) I removed the final residue and, while grabby, it came off just as it did at around 8 minutes.  You can see in the photo below how I removed the streaks from around the light reflection, but left those to the left where I removed the residue around 8 minutes.


Based on all this, I wanted to try and find a time where removal is too late and coating cures on the paint.  In addition, I wanted to see how the coating looks when dried/cured but residue not removed.  The below photos show a small section where I applied it and never removed it…


After about 8 minutes…


After about 10 minutes I decided to wipe it as everything looked completely dry, and it was.  I barely removed any residue as the rest was cured and bonded to the paint.  The coating cured just as I thought it would, in the same pattern as when it started drying up at roughly 4-5 minutes after application…


The 3 photos below show the same process but without the direct light…


~8 minutes…


~10 minutes and residue wiped off…


Overall, I’m very happy with the application of the Gtechniq CSL coating.  It is fairly effortless if you remove it within the right amount of time and if it performs as advertised, it will be a competitor to the other coatings on the market.

I hope these photos serve as a guide to how the coating cures, but as with anything it can vary based on temperature and humidity.  May be best to do a small strip on a bumper of the car you’re coating, wait until it looks like it did for me at about 7-8 minutes and remove it.  If it’s too late, you’ll only have a small section to polish off the cured coating and simply remove 1-2 minutes earlier.

I’ll be sure to update this article or post a follow-up after 6-10 months to show how it’s holding up and how much it actually resists swirls and other damage.  In the meantime, the product went on VERY easy and looks great!

Ivan Rajic LUSTR Deatil
Ivan Rajic
LUSTR Detail
257 N Woodwork Lane
Palatine IL 60067
Facebook | Instagram

53 comments on Initial Impressions & Application: Gtechniq Crystal Serum Light (CSL)

  1. David says:

    Nice review, but I wonder about paint prep for a product like this. Beyond a spotlessly clean finish, did you do anything to remove any previously applied sealant/wax for it to bond properly?

    • Ivan Rajic says:

      Hi David,

      I should’ve mentioned not only in this, but my other articles, but this is assuming the paint is polished and decontaminated as necessary before a coating is applied. So to answer your question, yes you should and we did polish and prep the paint properly to ensure as best a bond as we can get with the coating application.

  2. james melfi says:

    Nice write up Ivan, will have to try some soon!

  3. James Downes says:

    Very informative not just for this product but for coatings in general and top tip at the end I’ll be keeping that one in mind next time. Great post.

  4. Greg says:

    I am a certified Gtechniq installer and have used all the Gtechniq coatings. All of the coatings are top notch.
    Thank you for this review. I especially like the different drying time tests.

  5. Moheb hanna says:

    Hi Ivan,
    How u compare CSL aganist cquartz and 22 ple vx3 in terms of high gloss and swirls resistance.

    • Ivan Rajic says:

      As I said in the article Moheb, unfortunately I can’t compare it to anything now as I only applied it days ago and haven’t really tested it. I’ll be sure to do a follow up or maybe a new article comparing the gloss, durability and swirl resistance of each coating I’ve reviewed. To do this tough I’ll have to have them all on the same surface to make sure testing is a equal as possible.

  6. Mark says:

    Great review as always Ivan! I imagine that this coating has to rank up there as one of the most durable as far as coatings available to the consumer (non pro) go since they claim it has to be WET SANDED to remove. Not just polished like other traditional coatings. I’m anxious to see its scratch resistance.

  7. Pete Borras says:

    Great detailed review Ivan.

    I’ve had CSL on my wife’s black Lexus for 6mths now and I must say I’ve been very impressed by it. Just like you said, the application is very easy, the gloss is great as well as the smooth feel it provides. The other great advantage about this coating is the fact that it can be topped with EXOv2 or C2v3 right away.

    • Mark says:

      I’ve never understood Gtechniq’s “topping” system. They seem to recommend that each of their different coatings is then “topped” with a different coating. Even their pro coating Crystal Serum is suggested to have CSL applied on top of it. Now I understand the idea of the more layers the more protection, durability, longevity, etc., but there are plenty of coatings on the market that have the same longevity and durability claims from just one layer. A second layer of a coating is not only an additional coast, but also allows more room for error during the application. The reason I bring this all up is because I have wanted to try Gtechniqs coatings for a while now, but these factors always steered me away. Is the second layer really necessary?

      • Pete Borras says:

        Gtechniq has never recommended to have Crystal Serum layered with CSL. They only recommend EXOv2 or C2v3 on top of Crystal Serum for added hydrophobicity and slight additional gloss. Pay attention this is ONLY a recommendation. Not something you have to do.

        If you look at all long term coatings you’ll see they are a 2 part system. The base layer which is the one that gives you the true protection and the top layer which offers higher hydrophobicity and deeper gloss. Some examples are: Opti Coat Pro Plus, Ceramic Pro 9H+Light and Modesta BC03+BC05.

        If you want both of both worlds you’ll have to settle for a short term coating like EXOv2, C Quartz, Gloss Coat, BC05 or Ceramic Pro Light. Keep in mind this coatings aren’t really great at chemical resistance. They are more for the water beading and high gloss factor.

  8. Terry Kendrick says:

    According to Gtechniq, CSL offers 80% of the performance of the Crystal Serum.

    So, let me get this straight, Gtechniq wants me to pay good money to get 80% of whats available. Sorry guys-no thanks. I’d rather pay more for superior performance.

    This makes no sense to me. Maybe I’m wrong?

    • Reece @ DI says:

      Terry – Unfortunately Crystal Serum is a coating that only a Gtechniq Certified Installer can apply, it is not available to the public. The CSL, much like the Optimum Gloss Coat, is a version of a pro only coating that was made so that other consumers can get their hands on it. Does it perform like the Pro CS, no, but it is pretty close!

      • Terry Kendrick says:

        Reece…I understand your point. However, I spend money on this site and others to get the very best products for my vehicles. Personally, I’m not looking for pretty close.

        Any company has the right to decide how they want to market their products. As a consumer, I avoid products and companies that offer second best to consumers. I like to think my money is just as good as the next guy.

        • Ivan Rajic says:

          Terry I think you’re misunderstanding the advertisement from Gtechniq here. You’re not getting 80% of what’s available. You’re getting 100% of a product that is 80% as good as a product which is NOT available for purchase. That product that you can’t purchase, you can have put on your car only by paying money to a professional detailer (Gtechniq installer) to apply to your car after proper polishing. The CSL here is meant for enthusiasts who want to spend $300-600 worth of detailing materials to properly wash, prep, polish and coat their car multiple times, as opposed to paying $600-1000+ to have someone polish and coat with the professional coating.

          There’s no wrong or right here, just an option given and you can pick which best suits your budget and car. Hope that explains it a bit better. The whole point is that Gtechniq is not selling the pro-only coating to consumers, so this is the best you as a consumer can get from them.

          • Terry Kendrick says:

            Ivan…I do understand. I know Gtechniq best product is a Pro-version only. I clearly state they can market their product to whom they desire.

            I’m saying, as a consumer, I don’t want to purchase a lesser version. And I chose not to patronize companies that market their products in this manner.

        • Reece @ DI says:

          Terry – I would love to get my hands on the pro only version (Crystal Serum), but unfortunately it is not available to the public. Gtechniq, 22ple, Optimum, CarPro all have pro only coatings that are not available to the public as well. The CSL really does work great and if I am being honest, using a pro only product like the CS would be a nightmare for me. I seem to apply too thick in a few places whenever I personally apply a coating and using something that can not be corrected easily (CS needs to be wet sanded off if not applied incorrectly) would cause a lot of headache for me personally. Now I know that is not everyone, but I also look at it differently. I am getting 100% of a product that is available and will work great for me, the average consumer. The professional only CS is for someone who wants to spend that $500 – $1000 or more on a high end detail, and receiving an even higher end product than what they can apply. I certainly understand your point though, I always seem to want only the best as well!

  9. Dave T says:

    GTechniq products are top of the line. If you read some of the forums can you imagine them allowing the public to buy a product that has to be wet sanded off if not installed properly? It would be a nightmare. I agree with you, I would love to get CS as well, but I understand why it can’t happen.
    I ordered the CSL within a minute of seeing it available. Looking forward to using it.

  10. Jong says:

    How many cars can the 30ml bottle cover.

  11. DMac says:

    Any Durability / feedback from the applied coating?

  12. Chas Keithan says:

    Looking for some help/feedback. I’ve done 3 cars now with the GTechniq CS light/EXO combo and have waited 1, 6, and 12 hours before applying the EXO. (Directions are 1-12 hours) and each time, the EXO actually feels stickier than the CS light and takes away the slickness of the CS light. I’ve tried putting it on thicker/thinner and each time the EXO feels worse than CS light by itself.

    Does anybody have any ideas? When I put EXO on C1 it was amazing. I just don’t understand.

  13. JP says:

    CSL/EXO….3 weeks without washing the car, and 700 miles later – wow still beads and holds suspended dirt. Extremely impressed simply a coating of Ceramic above ALL thus far.

  14. Ketan says:

    Nice review.

    Can it be applied to vinyl wrapped car?
    It application instructions it says avoid any vinyl buy not sure if it’s meant for vinyl trim and car parts or vinyl wrap.


  15. Dave Tucker says:

    Just a comment for those complaining about not being able to get CS. Sorry if this is already mentioned, but can you imagine how many amateurs are going to screw up application as a percentage always do, then have the same amateur try to sand off with 1500 grit paper. That would be a disaster for them. I use Gtechniq products fairly regularly and have never been disappointed.
    One question. Forgive me I haven’t read the instructions in the box yet but read on another site there is no wait between applying CSL and EXO, just seems kind of odd.

  16. Saul says:

    Have you tried top it up with other coating? I have thinked to use CSL+Nanolex Si3d. What do you think guys?

  17. Saul Munoz says:

    Any updates guys?

  18. dennis okin says:

    still trying to understand if the product would work on top of expel ultimate or other vinyl wraps

    • Ivan Rajic says:

      I haven’t tested it but it should be fine like all other coatings. We’ve used most 22ple, Cquartz, Optimum, etc. on PPF and never had an issue. It does dry quickly so always do a small test spot first if doing it on your own.

  19. John Fritz says:

    Thanks Ivan for a great site and a great review. Are ceramic coatings a decent substitute, if any, for the vinyl wraps out there? Cheers

    • Ivan Rajic says:

      Whether you’re talking about vinyl or PPF/clear bra, coatings are not a substitute John. They’re meant to be a more “advanced wax” for lack of a better term whereas the films are actually protecting the paint from paint chips and road debris. Definitely a must have if you want to keep the car looking great with easier maintenance, but no coating will replace the protection of good film like Suntek or Xpel.

  20. Gunnvald Kleveland says:

    Even if its short time since applying , would you say its a product you would add or replace another coating in your arsenal Ivan ?

    • Ivan Rajic says:

      At this time no, but I will be getting another bottle to slowly insert into the “standard” coating line up and see how it compares to the others in terms of durability, application process and price. I’m a big fan of 22ple and that’s still our go to product.

  21. JP says:

    How long do I need to let the car sit after applying CSL?

  22. Ryan Sturdivant says:

    From the Gtechniq FAQ site:

    Q: Can Crystal Serum be applied on vinyl, wraps and matte finishes?
    A: Yes, but we recommend C1 over coated with EXO as a more suitable solution.

  23. Frank says:

    Hello Ivan great how you tested it to the fullest and see what would happen! That’s something I would do!!..anywho…my question is if the panel starts to crystallize or harden on the paint after 8 minutes +\- , won’t your applicator pad by ruined after a certain amount of time?? or if you may happen to take too long to do the whole car..always wondered that on certain coatings…other coating include multiple applicator pads/cloths..

    • Ivan Rajic says:

      Great question Frank. Yes the coating will harden in the applicator, but it seems like regardless of coating it always takes longer than the actual “dry” time for paint. It’s because the time where you have to remove it from the paint doesn’t really indicate when the coating is “hardened”. Rather when it’s dry to the point where if you don’t remove it, better yet, level it. In other words, say it’s 8 minutes to remove from paint… well that 8 mins doesn’t mean coating is hard, just means it needs to be leveled. It may be 15, 20, 30, etc. until it’s actually hard. We normally replace the applicator every 2 sections, so roughly every 16 minutes in this case.

      Hope that makes sense.

      • Frank says:

        Gotcha!. Makes perfect sense actually!. Thanks for the reply Ivan. Appreciate you and all of the other awesome detailers here on the DI team that help out guys like us

  24. Saul Munoz says:

    Does it work well under other coatings?

  25. Dallen says:

    I see your useing a controlled environment but what about someone like me I have a garage but it’s not Air condition id like to use csl but I can’t replicate 77 degrees has anyone ever tested it in a non- Air condition environment also like to add I live in very hi humidity area gtechniq saids after applying immediately whip off would the same rule apply for me. I’d love to use this for my detailing and offer it to my customers

  26. Vedran says:

    Hi Ivan. I have two questions. What is the difference between C1 Crystal Lacquer and CSL? And what about durability of both? I’ve came to the next conclusion: C1 + EXO – minimum 3 years; CSL + EXO – minimum 5 years. Am I right? If you speak serbian I would have few more questions 🙂

    • Ivan Rajic says:

      Hi Vedran, unfortunately I’m not Gtechniq expert and can’t answer your questions with certainty. Looks like the C1 is a less durable coating but I’m not sure exactly of how it compares with CSL. CSL has done very well in terms of durability and I planned for months now to start using it, but still haven’t tried C1. Hopefully someone with experience can chime in.

      • AYAZ says:

        I will be doing CSL+EXO3, how long is wait time to wipe the coating? I will be doing this in end of March in NYC Weather.

        • Ivan Rajic says:

          Ayaz, you’ll really have to experiment with it on a small section. There’s unfortunately no timing chart with coatings depending on weather, so temperature and humidity play a huge role.

  27. Curtis says:

    Ivan, what product did you use to remove polish residue from the paint before you applied CSL?

  28. Roger Young says:

    Any updates on the durability?

Leave a Reply

Your email address will not be published. Required fields are marked *

Commenting Rules

  • Try to keep your comments as relevant as possible.
  • Don't be abusive: no personal attacks or any other nastiness.
  • Feel free to express your opinion, but do so in an eloquent way.

If you do not respect these rules your comments may be edited or even deleted.

My Offers
Snow Day Savings
Quantity Discounts - Buy More, Save More!
Big Discounts While Supplies Last - Clearance Items - Shop Now
Free Stuff
Close overlay