Gloss Coat -weird water behaviour degradation


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Gloss coat is exhibiting a weird "degradation pattern" on the car after about a month and a half - beading/sheeting is pretty much gone on the hood (towards the windshield and the center - sides and front where there's the most debris are way better) and on the roof... the upper part of the rear rocker is slightly more degraded as well, but the sides/rear of the car bead/sheet fine 🙄

Here's the story so far:

Car is a MY09 (September 2008 manufacturing date) lexus gs450h, sillver metallic (paint code 1f2). Gloss coat was applied initially around the 15th of September this year, the following way:

  1. Snow foam pre-wash
  2. carpro reset
  3. pressure washer rinse
  4. iron remover, quick clay
  5. ONR wash (with BRS)
  6. polish (DA + orange opti pad + hyper polish - wanted to clean, a couple of RIDS on the car don't matter - silver metallic, after all + it had been fully corrected a year earlier with meg's twins, then protected with two coats of fk1000p + sonax BSD for maintenance... the few RIDS were mostly on the hood due to weird attempts :D )
  7. ONR  wash again (with BRS)
  8. dry
  9. coat of paint prep on the whole car
  10. gloss coat, light paint prep pray on each panel a bit (1-2min) before application, 4CCs used in total (without front bumper and mirrors), wipe away was 10 minutes post application (waffle weave towel), high spots weren't visible except on the hood, the "oil slick" was only visible under certain angles... silver metallic car, I guess - can't see other waxes too much either
  11. opti seal after an hour or two
  12. 3 weeks later, carpro reset + onr + dry +  hyperseal (after drying, using the opti-seal applicator - I keep all applicators in a bucket full of ONR so hopefully no cross-contamination).

This was all done outside, 20deg. Celsius temperatures during daylight. Coating was applied in the morning, and I accidentally left a few high spots at the center of the hood - accidentally squeezed the ONR needle, thought I wiped everything down but the center of the hood was properly "dotted".

Come October and all the rain, I noticed that the water behavior was severely degraded. I read around, got power clean & MDR, threw everything that I could on the car (OPC@3:1, MDR left to soak, snow foam, reset, IPA, Meg's d101 (probably not a good idea), carpro eraser, ,  all these multiple times and in different order while checking for water behaviour in between with a pressure washer) and the results didn't change - the notable parts were that the paint lost water behaviour the most where the sun was shining at it directly in the morning.

Since I had used a topper (hyper seal) and non-opti products (carpro reset - even though it should not be a concern from all that I've read so far), I decided to recoat (around the 25th of October, apparently) after doing just about all of the above again, minus the polishing - I only polished the high spots off the hood (which took some time - the gloss coat was still there, despite the flat water behaviour), used a heavy does of ONR + a synthetic wash mitt to clay the rest of the car, which didn't really take anything off. This was at the end of October. Since the we've had a lot of rain and some snow, and the washing routine was limited to pressure washing and ONR + BRS only.

At any rate, today I decided to decon since the car wasn't beading well at all - MDR agitated with a microfiber, rinsed with ONR after 10-20 minutes (did the whole car then started wiping the same way - probably 20), dilluted OPC at 3:1, sprayed all over the car (this initially killed water behaviour), wiped down with ONR again - the sides and back of the car sheet decently well, but the hood and roof are... mostly gone. I'd say that the most level parts of them are the worst affected - towards the middle of the car. Funnily enough, the boot is fine. The sides and rear recovered pretty well after decontaminating - as in, they still sheet. Nothing like BSD or anything along the lines, but from what I've read, coatings in general don't really do that without some form of topper. Tried a coin-op wash as well ("shampoo" + thorough rinse), just in case - no difference, other than the roof getting accidentally sprayed with their "wax" thing, which I'm guessing will wear off in no time.


At any rate, any ideas as to what could be going wrong? I'm wondering whether it can be sun exposure, or the opti-seal application after the gloss coat application being left on the car, or something along the lines... I've never had these parts of the car lose their beading/sheeting so quickly - 2 months of winter driving with no reapplication of anything to the hood & top (BSD on the sides) did almost no damage. All glass has been coated with GTechniq G1 since summer last year, and it doesn't appear to have degraded, but glass is way harder than paint, so there's that... I don't know what to think.

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with all the detail you provide, you say you re-coated but didn't mention how much Gloss-Coat you used.  Your original application of 4 mls is about half what it takes to do an average car.  With all the various products and applications/polish, you've for sure reduced the amount of ceramic on your paint. You mention MDR, snow foam, IPA, Power Clean, Megs 101, Erasure, and multiple applications.  Gloss-Coat is not as chemically resistant as the Pro line and I wouldn't be surprised you've stressed it to the point of failure. 

As for beading/sheeting, someday I'm going to start a "pet peeve" section and the various arguments concerning the size of water beads, the shape, how fast they sheet, etc will be high on my list (along with slickness and "gloss").

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The re-coat used 4-5cc as well - my thoughts were that I used too little originally as well, so before each panel I wiped on a dark surface (the roof glass) to see if the coating was still being applied - did a few drops in between panels regardless. I haven't polished between the coat, other than the high spots on the hood - I too thought that the coating might've been under-applied, but the hood & roof (and especially the hood) were the two areas where I started and applied a bit too much (or so I'm thinking) initially.

The videos in this thread:

...actually sort of match what's on my car right now - the hood/roof are somewhat worse, the sides are somewhat better. I haven't thought of lifting the hood to check for gravity affecting things that much.

My current thoughts are that the night dew might've affected the coating's curing somehow - in the first instance the hood was done at 6pm (a bit before sundown) and the rest of the car was done somewhat early in the morning, in the 2nd instance it was at 4pm - right after decon and with the sun still shining, wanted to see if the high spots would be visible (nope, super hard to spot the oil slick again... and then it melts into).

Was thinking about trying to apply a whole new syringe of gloss coat on the car & to let it stay for a day in the garage without any sort of protection (the car normally sits outside), but the temperatures right now are sub-10 degrees C, and the forecast is rain & snow in the coming weeks.

In terms of chemical resistance - IPA, meg's 101 and eraser were tried on specific spots only - the rear left quarter panel (initial decon try) and the hood (the one I did a few days ago). From what I've read so far, I thought that OPC (even at full strength) and MDR were safe to use on the coating.

Slickness and gloss - not too concerned. Gloss seems to be incredibly subjective (we're not walking around with "gloss meters" hehe), and slickness does not necessarily indicate contamination and water resistance... not that the beading/sheeting properties and  the paint protection (as in, contaminants/ease of cleaning/etc) are directly linked :D

Edited by Lwerewolf
hit "enter" twice and posted this while unfinished... >_<
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