I sprayed mineafter the material sat on my shelf for about 8 months. The adhesion promoter was thick and was very difficult to apply using the spray bottle supplied....I ran out about 3/4 of the way and had to expedite shipping another kit.....I took great care in sanding and prepping all surfaces and ended up with nearly every inverted corner having a "material bridge" where the liner pulled away from the surface while drying. The liner on the tailgate peeled off in 1 sheet like teflon.....Might have been the old adhesion promoter....Overall I was not impressed....This was not my 1st liner to apply, but I went with Als due to the color(tan) and the HNR.
Did your HNR peel off the metal, or did the liner peel from the HNR?
I just did HNR & liner 2x because the HNR didn't stick to the tub. Peeled up in sheets, except where it stuck (about 25% stuck & took many, many hours to remove). I called their tech line & they replaced the HNR & liner, but obviously it was my labor to reprep. They said the HNR doesn't have much adhesion and that etch prime is NOT adequate for the HNR on bare metal. I wasn't really impressed with how HNR "stuck" to the old paint, so I ended up epoxy priming the whole tub before shooting it the second time. I wouldn't trust HNR over anything old or possibly contaminated, ever again. I assume the same for Lizard Skin. The end result is good, can't wait to get it on the road & see how the HNR works. I used a shutz gun and liked it for the whole tub job, but the hopper works ok for less complicated jobs.
We shoot the Scorpion (commercial name of Al's) at work regularly, and have very good luck with it.