The rear muffler panels and welds on exhaust tip pipes, rust. Could use black barbeque paint but access is difficult. I coated mine with Rust-Olium Rust Reformer. See pic, before treatment on bottom, top pic after. Make a PDF showing details of this simple procedure compared to painting these areas with high temp paint or investing in a blanking panel. This is a PDF with detaild proceeedures: http://www.netwelding.com/Muffler_Rust.pdf

 

I hate playing with chemicals, painting too. I'm not going to look at the mufflers, hopefully will not see corrosion. If it shows, I will cover the rust with flat high temp paint. Certainly not going to get carried away. Another thought, maybe warranty will cover it.

 

Instead of modifying the original with non-spec paint, why not just wait for a failure and have it replaced with a brand new one under warranty?

If you start painting the rust that's visible, I'd be concerned that I'd cleaned it well enough before painting that the new paint would actually stick over the years. Then I'd worry that I got it all, and figure I'd have to remove the whole thing to inspect the hidden surfaces. So why not just wait until your 3 years or 36,000 are close and have the dealer inspect it?

 

It's not a warrantee issue, all 409 stainless welds rust! It’s not rusting through, just looks bad. The Rust Restorer is less toxic than paint. It doesn’t smell! You’ll find, when you do look it will be very difficult to reach the welds to paint them unless you remove the bumper. Suggest you don’t look, you’ll feel better!

 

I'd rather have a plate...even painted, I don't like the look of seeing the mufflers behind the trumpets .....kinda like wires hanging down from your flat screen on the wall TV....

And BTW, rust may not be covered, might be considered environmental....usually gotta break for warranty...

 

The dealer will not do anything! It won’t rust through in 36,000 miles or 3 years. It is just the appearance. Mine took about 6 months to show the surface rust you see in the picture. The exhaust per the GM Order Guide is made from aluminized stainless steel. It is a less expensive muffler steel than the 18% chrome, 8% nickel you generally think of as stainless. The welds are not aluminized, only the materiel itself. Therefore they show the rust and all the weld spatter is rusty as well. I recall folks commenting on this when only the test cars were seen in the summer of 2013. All the cars will see this issue. Perhaps best you don’t look! They do sell cover plates which just hide it!
Also, there is no such thing as spec paint, these parts are not painted. In fact rust restorer is recommended as a pretreatment before you paint with a high temp paint. Have used it for that as well on other projects.

 

you're on the right track...although rust never sleeps you can retard the process with barrier coatings, as you are wisely doing early in the game. What folks don't realize is when you wash your car, and spray underneath, you can cause a rusty drip onto your nice new concrete driveway, or garage floor. Also, driving home in the rain can do a similar gremlin. So, not only does it look crappy on the car, it gets to be a nuisance around the house. The best product I have found is POR-15 paint. http://www.por15.com/

I used this stuff on my C5 rotors as well as on my lift to cover up rust permanently. Buy the little kit with the phosphate pre-treatment step for best results....it works very well. But don't use it where it cn be exposed to sunlight...it will chalk and begin to rub off when brushed against...this is normal for all epoxy coatings. But that won't be an issue for the C7 exhaust.

 

Nice job cleaning up the rust. Hope it stays off there for quite a while.

 

Good suggestions, thanks.
Will consider for the center of the rotors, so far they are fine. To paint the muffler rear panel and tip pipe welds you would have to remove the rear bumper. Much easier to repeat the rust reformer when needed. 409 stainless is much better than carbon steel. It will last for years, just doesn't look good!

 

removed lower fascia & painted mufflers black

 

[QUOTE=C7Jake;1586978755]removed lower fascia & painted mufflers black

Forum comments indicate to get the lower fascia off it is best and easiest to remove the whole rear bumper. Apparently that is the GM proceedure. If you don’t you have to pry off the side lights from the outside to access bolts when the lights are designed to be removed from the back with the bumper off, etc,.
Did you remove the whole bumper?

 

Just the lower...takes 10 minutes

 

Boy, the following didn’t sound like a 10 minute job! It also notes you need a helper:
Flowmaster Instructions for Installing Their C7 Mufflers (just the part before the muffler removal and install):
1) Before you begin, please understand that the installation of this system requires significant disassembly. The entire lower rear bumper fascia must be removed. Because this is a painted body panel, you may want to consider covering it with masking tape for the disassembly/assembly process to prevent any scratches.
2) Begin by removing the rear license plate. Next, along the bottom of the bumper fascia there are several screws that secure the lower edges. Remove all of these screws (save all fasteners for reassembly).
3) On outside ends of each side of the bumper fascia there are small, plastic vertical grates that must be removed. These are held in place by small clips. Use a small screwdriver to carefully pop these out. At the bottom, where the red and black panels touch, they clip together. Use a small flat blade screwdriver to carefully separate them.
4) On each side of the bumper fascia there is a thin horizontal red reflector that must be removed. It is held in place with clips. Use a small flat blade screw driver to very carefully pop out these two reflectors. Once the reflectors are removed, you will see two hex bolts that secure the fascia to the bumper frame. Remove these two bolts along with two that are located under where the license plate was mounted.
5) In the cavity just above the exhaust tips, there are two last hex bolts that need to be removed. At this point the panel is ready to be removed. We’drecommend that you have a helper for this part. The panel is secured along the top edge with clips. Grasp the panel at one end through the vertical slot and carefully pull it out. This will take a little muscle and finesse but it should pop right off. Once it’s off, place it in a safe area out of the way.
6) This is what things should look like now. (see pic)

These comments were made by two posters indicating best to remove the whole bumper.
Glen e: See my build thread for some pics ... Basically, pull off tail bezels bolts in rear wheel wells, Cross underneath, inside across top , disconnect a few connectors and cable for hard key lock and it pulls off. Once it pulls off, break it apart from upper fascia .
Richescorvettes: When we did ours we removed only the lower fascia as I didn't want to disturb more than was necessary. In retrospect though I would agree with Glen that removing both the upper and lower sections as one unit would be much easier.

 

thanks for the research...and, YIKES!

 

Agree! I wanted to put paint over the rust reformer. In fact that is what I have done in the past. However also used straight rust reformer, and it worked fine, just only applied to the rusted areas. Waiting to a 3rd brake light pulser to be offered for the C7 like I had for the C6. Need all the help I can get to keep cell phone and texters away from my rear! Probably will require a rear bumper remove! I do all my work myself so hope removing the whole rear bumper is easier!

 

To remove lower fascia:
1. remove plate, reflectors & lower vents
2. remove 8 bolts...2 above exhaust tips, 2 behind plate, 2 behind each reflector
3. remove 10 screws on fascia bottom - 5 each side

Pull fascia, mask tips & spray away.

trim tool/power screwdriver...10 minutes no problem