Coating for body panel backsides

[Antsa]

After purchasing some body panels for my car I was wondering what would be the best coating for backsides of the body panels? The panels are from Audi, so they have that factory e-coating but is it sufficient? Maybe 3M 08800 sprayable sealer? Ordinary car paint? Any other stuff? Experiences on the subject are welcome

[steve briance]

The e coating does last pretty well but for longer service I would definitely add something on top. Which panels are they? It might make a difference knowing where they will be in service to direct whether you need rubberised coating or just good old waxy coating

[Antsa]

I have new front fenders and rear quarter panels plus good condition used doors. Current fenders are non salvageable and luckily new ones are still available from Audi. I was planning to make the new ones last at least the same time than the original ones

[steve briance]

The arch liners do a pretty good job of protecting the inside of the front wings. The factory way of dealing with that surface appears to be a solid brown wax sprayed on the surface. The 3m 08800 looks pretty impressive but maybe overkill for somewhere that has plastic shielding?

I like dinitrol products and have just been using some 4941. It is meant to be heat resistant so won't liquify and run off horizontal surfaces on a hot day. I've also used 447 on the underside which is similar to the 3m stuff in that it builds a textured flexible layer (but not as thick) i used 4941 over the top of the 447 and it beads water like a decent bodywork wax. Does give the impression of protection.

The dinitrol products all come in handy aerosol or air gun applicator tins if you have access to an airline.

[Antsa]

Thanks for the tip Those dinitrol products seem to be readily available.

[steve briance]

The only thing I can say about dinitrol products is that there is such a big range, I can be confusing to know what to get!

Just in case you want to paint over your costing to body colour then you can't use 4941, you might need to go for the 447 stuff which you can paint. I'm not sure I would as You can't see behind the arch liners when they are fitted but just for information

[Vorsprung durch Technik]

Audi Front wings seam to rust eventually mostly depending on where you live or the car is used and or mileage and the amount of salt used on local roads. The only way to prevent this would be to use an epoxy primer on top of what you get when buying a new wing. Adding some body shutz (stop chip) as a further layer will be way better than Audi built them.

What makes the front wings go is where the plastic liners get particles of sand between the wing lip and the liner. Constant flexing in relation to each other cause the paint surface to be compromised eventually exposing bare metal and rusting. A way round this is to add a thin layer of rubberised shutz on the wing lips to prevent this problem. Dinitrol products are really good and a must of you want to help things further.

[Error404]

Epoxy primer followed by 2k 3M 08800 or UPOL Raptor.
Also fit stainless rivnuts instead of the factory items. Do this and the panels will last forever.