I recently purchased a 1968 impala that i am looking to resore, among other things the car has a bit of rust on it, the truck was covered with rust, and there were a few hole in the trunk because of it, I sanded the whole thing doen, and applied POR 15 to where ever i could reach, I am going to take up the carpet and remove everything from the interior and put the POR 15 where ever I can. But i was wondering. If I accidentally put POR 15 over a nut and bolt, will the nut and bolt mend together? also is the matel pre extremely important when applying POR 15? For example, for my trunk i just sanded everything down and vaccumed out the rust dust and any other dirt or crud i could find. and applied the POR 15, I know it will hold but how well if the metal wasnt cleaned and all that junk?