Did you scuff the base coat before spraying? 24 hours means the base was fully dry and therefore the clear cannot bite into it to hold. The lines sounds like tiger stirping to me, not enough overlap. If anything, I'd listen to whatever SprayTech has to say or offer. Before I ever got into doing auto body and paint as a career, SprayTech taught me a LOT of things and everything he taught me I actually tried hands on and it worked for me and I still use his techniques or what he taught me today. As for gun, I use the Iwata lph400 as well and it works awesome on clear and base coats. SprayTech, when you use the Iwata 400 for metallics, are you using the purple, orange or silver cap? Orange is their new cap for kandies, flake, etc and the purple is the base cap and metallic, silver is clear but I've shot base out of it and it worked fine...