ElCid79

So I bought a 304ss Exhaust system to mount to my stainless works headers.

I ran ran into some fitment issues and took it in to my local exhaust shop to get it sorted.

I forgot to specify which which type of steel my pipes where. The did a very nice job installing and replacing a few bends to make it fit. I spent about 300 on the install / new segments. Which I felt was pretty reasonable.

When I went to pick it up I asked the tech what type of pipe they used, and he said it was aluminized. So I am kinda kicking myself for not specifying 304ss. But it is totally 100% my fault, so I obviously can't complain about it.

Is there any issues with having that one section in aluminized sandwiched between 304?

Obviously once it rots out out I can replace that chunk, but how should I handle it? I live in the south and road salt isn't much of an issue. My gut says it's perfectly fine, I just want some other opinions.

Thanks in advance.

J

resdoggie

I wouldn't lose any sleep over it. Probably last for years.

Gale Banks 80'

I find it odd that it fit so poorly that they had to replace bends and not just tweak them a bit. The first Exhaust I ever built I used 304 SS Mandrel U-Bends and I hand cut everything with a hacksaw and filed all my joints. I tack welded everything with a torch cause that's what I had at the time. Once I had it all fitted I took it to a shop to have them weld it all up. They welded it all with mild steel. I could of killed them. It prompted me to buy my first Tig welder.

ElCid79

My car isn't remotely stock underneath. So I feel that a fair bit of the figment issues were due to that. The vendor I purchased from is a well regarded forum vendor.

rodhotter

there are few shops that deal with any stainless steels, mandrel bending is also rare. those living in bigger cities or near a high end hot rod shop can consider their good fortune!!

TimAT

Dissimilar metals corrosion. I went to a class at Boeing a few years ago that was all about corrosion. Got a couple of really good charts, but I can't get to them right now. Here's one I found online.. Google search.
http://www.preservationscience.com/m...vanicchart.gif

7T1vette

They are both steel: one mild steel with aluminized coating; one is stainless with some other elements added to the steel when molten. The more important question would be, "what rod did they use to weld it?" My guess is that they used cheap steel rod, and that will be the weak link in the system.

I highly recommend that you clean the welded joints and give them a good coating of VHT 'Aluminum' paint to keep those welds from rusting on the outside of the tubes. That color should be pretty close to the color of the aluminized pipes on your car.

68notray

I have my own commercial exhaust tubing bender and can tell you from experience - stainless tube is awful to work with. Very hard dry alloy, does not like to bend and will kink in a heartbeat. Aluminized is great stuff

rodhotter

aluminized is cheap + easy but if you actually drive in the rust belt its short lived!! within a year mine looked like a POS + in 3 years it got replaced. i choose carefully + keep my rides quite a while so i can enjoy the upgrades i do so its at least T409 stainless. on my 56 chev that got used more than most i had a set of 304 stainless mufflers from stainless specialties that went on 3 sets of aluminized exhaust systems!!! your $$$$ your choice!!

Richard454

Like 7T1 said-

I'd at least spray some high temp paint on the welds.

I just finished up my custom sidepipes with SS 304,

It's tough to work with AND expensive- but only wanted to do it once and like the looks.

rodhotter

nice work!!! its amazing how good polished 304 can look, if done well it rivals chrome with minimum upkeep. the megaphone silencers on my triumph bonneville are an example as everyone thinks they are chrome!!! exterior corrosion is seen but coated or chromed mild steel is dying a slow death on the interior as well!! if you have the $$$$ do it once with 304!! or better 316 for more $$$$

73racevette

304 and aluminized is fine assuming they/you used 304 rod and preferably back purged it to weld it. 304 is what is used to weld stainless to aluminized. 304 rod would work when welding 409 stainless to aluminized as well.


Don't use steel rod for this though as it will create a crystalized structure and be brittle being the weak link as mentioned above.