Is it rust or isn't it?

So was washing the floorpan ready for sound deadener including some rusty water that had dried from the A pillar.

Anyhow, the floorpan is KBS'd, Oz POR15, and so thought be OK but after washing the rusty residue away there was either actual rust or rust stains showing on the areas where air bubbles had formed whilst the paint solvent flashed off.

A few pics if you can make things out.





So my dilemma is trust that water hasn't reached the floorpan metal via the air bubbles and lay the sound deadener or bite the bullet and strip back the KBS to apply a new coat before the weather gets too warm.

Frickin Aussie summer made the paint dry before it could flash off properly. 🙁

Personally I'd be taking the safer option. Otherwise you are going to always wonder if there is rust under your sound deadener.

Also when I did my floor, I originally did it with the shell still on top. I got some bubbling with POR15, so ended up redoing it with the shell off, which made rinsing between processes infintely easier. It also produced a much better result and I feel much more comformatble I have a good barrier to rust.

its not just from using a grinder near by and the waste rusting ?

Klaus wrote:its not just from using a grinder near by and the waste rusting ?

Well like I said there was some rusty water that had settled there from the door pillar and had dried out. The dried rust washed away to leave these 'stains'?

Any grinding was done over a year ago and the floor was brushed and vacuumed afterwards.