Should I just lighten it up and take anything loose off the paint?
You’re claying the vehicle after you washed it, right? If not then that’s the problem. Wash it 1st! Lol. I doubt you’re making that mistake though...
As far as the claying, if your vehicles are as neglected as you’re describing then yea it can sometimes take an extraordinary amount of time to fully decontaminate the paint.
On the car I recently bought, the paint was in such bad shape that I had to clay the paint a total of 5-6 times very thoroughly until it was fully decontaminated and it took a good while but in the end it was totally worth it.
[the paint was in bad shape]
Don’t stop until the claybar comes up clean... As you can see there’s still a long way to go.
This was after about the 3rd or 4th time of me claying the same panel... Almost there.
Finally, after about the 5th or 6th time it was finally clean [no more gunk coming off onto the clay and the paint was perfectly smooth]
Once your claybar shows up clean like that, any visible gunk left on the paint will only be removed by polishing. The clay does alot but there may be some stuff that only polishing can take care of.
As far as iron removers and spray decontamination goes... The honest truth is they’re overrated. Yes they do their job at removing iron contaminants, but the majority of the decontamination will be done by the claybar.
For example, I still had to clay 5-6 times even after doing the iron decontamination Twice.
1st time.
2nd time.
And I Still had to clay 5-6 times... That’s proof that iron decontamination is overrated.
...Keep claying until the clay comes up clean, sometimes it takes a while but it’s worth it.