How to keep new cat back exhaust.....rust free?

[1 SX]

Hey, I had this new American made full cat back installed at a local shop. They used 3 new hangers, and welded all connections, and hanger supports to the main pipe. Sounds mint. Its also new car tight. So to keep this for a winter I've decided to paint the new exhaust with flat black high temp 600?F. Question is what is the permanent solution? I want to keep it rust free. I did all the welds and main pipes with the muffler. It even looks great. Repaint every 6 months? Forget about it? Thanks!!

 

[dparm]

Even stainless will develop a bit of surface rust. It's inevitable because of the heat and condensation.

Anytime I've had work done they just spray the welds and flanges with silver paint to slow down the corrosion.

 

[Hallmark]

A stainless Magnaflow cat-back mated to an OEM stainless F-150 system is currently rust free after 8 years of use on my truck. If your system is stainless, you should expect the same (albeit there is no winter street salting in my area). If your system is not stainless...?

 

[dtt004]

Hi.

It depends on the type of steel used. A martensitic stainless steel (420 series) is cheaper, and provides a good balance of corrosion resistance and price. An austenistic stainless steel (304 series) provides greater corrosion resistance, but is harder to work with, so it's more expensive. The most affordable solution is aluminized steel, which as you can conclude, provides the least tasteful looking steel, but provides good corrosion resistance.

If you want to paint, you need to roughen the surface of the steel to allow for adherence of the particles. Most stainless will be polished to a mirror finish. If you paint that, your paint will not adhere well.

I have a 304 series exhaust system on my cars. They have not corroded. I go skiing in my truck, and we hit a lot of salt. The key is to clean the exhaust system, no matter what kind you have.

 

[snapcrackle12]

Move to Texas!

 

[Samilcar]

Cold galvanizing zinc paint.

 

[mechtech2]

A clean surface and paint will help, no doubt. Clean the protective shipping oil off.
But count on touch ups rather frequently.
Your efforts will result in a log lasting exhaust.
Let rust get started, and it is harder to stop/control.
Remember, the insides can rust from excess water from cold conditions/short drives.

 

[dwcopple]

Originally Posted By: Samilcar
Cold galvanizing zinc paint.
+1
Rustoleum makes one. That is what I use.

 

[mechtech2]

Originally Posted By: dwcopple
Originally Posted By: Samilcar
Cold galvanizing zinc paint.
+1
Rustoleum makes one. That is what I use.


I forgot about this stuff. Good point. I hope it takes the high temps.

 

[dailydriver]

Originally Posted By: Samilcar
Cold galvanizing zinc paint.


This, or triple coat powder coating, or a very good multiple ceramic high heat coating process, both of which will cost you at least five times the price of a custom aluminized steel system.

So yes, the g.z. paint, or just find a high temp primer and apply the high temp paint (I would use the VHT 1200*F+ flat black myself

) over that.

 

[John_Conrad]

no sense in starting a new thread!

i'm going to try this cold galvanizing zinc paint on a new exhaust installation...is there a specific primer to use?

 

[JamesBond]

I just put on a cheap walker muffler on the beater last fall. Before I installed it I roughed it all up with sandpaper then cleaned it with brake cleaner. Then put on several coats of flat black rust oleum bbq paint. I also drilled an extra drain hole. It looks good so far.