I have some concerns about the Gtechniq L1 Leather Guard product. I've applied it to a few areas now in the front row: the seat pans, lower sides of the seats, arm rests, door arm rests, and head rests. I read the application instructions several times, and I watched a video online showing its application on seats in a Porsche. The instructions on the bottle read:
- Thoroughly clean and dry surfaces
- Apply in a circular motion using a clean lint-free cloth
- Allow film to dry and then buff with a second lint-free cloth
- For optimum performance apply 2 coats of L1 allowing 24 hours between applications
Fine. I did that. Although I never noticed any residue. I never used any force during application, just a spreading action. I wasn't trying to clean the surface, just treat it.
The spray doesn't output a lot of liquid, and so it takes quite a few sprays to get enough to spread around. At first I used a microfiber cloth, but that seemed to be absorbing a lot of the product. I switched to an old white T-shirt. That worked much better because it didn't absorb as much product. After drying, I used a clean microfiber to wipe down the surface and remove any residue.
Then a few days later I noticed that the T-shirt was literally coming apart where the product had been. Also, there is some discoloration that matches the color of my leather seats. I tried googling this, but found nothing. It appears that the L1 product is eating away the fibers of the cotton shirt. Although the photo shows that there aren't any holes, so it's not really being "eaten." There are many small (1 cm) linear cuts. Maybe the L1 product weakens the cotton fibers and they then shred from the small shear forces involved.
So, I don't know what's happening. Heck, maybe it's interacting with some chemical that's in the shirt after surviving many laundry cycles. Maybe I should have flipped the T-shirt more often during application. Maybe I just used too much L1.
I'm just a little concerned. I've stopped applying it on other leather surfaces. I'll watch it carefully to see how it ages and wears over time.
In the meantime I'll try to devise a careful test.
For what it's worth, the bottle indicates that L1 contains: 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-2H-isothiazol-3-one. I'm not a chemist, so I guess that's all good stuff.