Just wanted to speak up and clarify a few things based on follow up comments.
Firstly, Kevin didn't really tell us what was going on with the inside of this panel. For example, are there any coatings that have been sprayed or coated from the factory or the owner, such as any wax coatings, rust prevention coatings like Fish oil, Tectyl 506, etc. If there are these types of coatings present, they will contribute to causing contam probs. Using detergents and power water washers on the inside panel to remove these types of coatings is pointless, as detergents won't break down and rid the greasy, waxy coatings properly. Power washing contaminated greasy, waxy coatings on the insides of panels will also contribute to more contamination moving and migrating to the outside of the panel. If no such coatings are present,or were ever used, then by all means, power wash away to help clean the inside panel.
Secondly, MotoArts said .........As explained to me, the solvents only smear the (silicone/oils), they will not remove them. I can't speak from any experience in regards the application, and adhesion of graphics on automotive paint surfaces, but i do know how wax and grease removers remove wax, oils, silicones and grease from all substrates prior to the application of the auto paints. If the procedures are carried out properly, all contamination will be removed. If any trace contaminant residues were left on the surface prior to painting, you would be guaranteed to get ongoing reaction problems that would never go away. Quality wax and grease removers WORK, with the exception of pre contaminated panels that weep out contaminants below the paint film. That condition can be very hard if not impossible to solve in certain instances. Also, yes, prepping some water based paint substrates and raw plastics with solvent based wax and grease removers is not recommended. Paint companies now provide special dedicated cleaners for these applications. I use them myself at work.
Thirdly, as i mentioned before, spraying any fresh paint over a contaminated surface is risking loss of true adhesion, and some strong waxes, silicones and sealers penetrate deep into the paint films. I have seen examples where the contamination goes into the metal and causes problems in removing the contamination as well. That's why i stated that in Kevin's case,removing all existing paint down to the bare steel is no guarantee of totally eliminating his contam problem. Looking at his situation realistically, he has already lost his money or profit margin by having to go over and re correct the failed paint applications done already. The exception is of course that this job for his friend is a non paying love job. So carefully sanding down what he's got now, carefully cleaning the surface with wax and grease remover several times with fresh wipers, then priming up the whole panel would be the most cost saving realistic way to go for him now i feel. Going back to bare metal, priming, body work, more putty/ primer, and then color and clear is a definite option that may bring the proper results, but done properly is a lot of hard work, and will take a lot of time and materials. If money plays a part here, he would be really loosing money big time on this job going down that road.The decision is entirely his on which way he wants to go. He has options here.
Greg.