Exhaust pipe coating

[White Lincoln]

Question:
Now that I have my mufflers welded to the exhaust pipe, I decided I would wire wheel that ugly orange / beige color from the exhaust. Since I did this, do I need to spray the pipe with high temp engine / exhaust paint or coat the metal with something else? I may have just stripped a protective coating off the exhaust.

 

[KevinVarnes]

If that is 409 stainless I'd just leave it alone. Even if it is aluminized it will still probably last 100 years where you are.

 

[White Lincoln]

If that is 409 stainless I'd just leave it alone. Even if it is aluminized it will still probably last 100 years where you are.

It is OEM exhaust from a 95 t-bird.

Thanks Kevin!

 

[Grog6]

stock is stainless, so polishing it wont hurt. it turns brown with heat, so it will go back to the brown color eventually.

 

[AdamG]

Stock is not stainless on tbirds, maybe it is on mark viiis but I've seen plenty if rusted out exhausts on these cars. In New Mexico you might be fine but I'd still put a coat of high heat exhaust paint on it to just help it.

 

[KevinVarnes]

From what I have seen the stock systems were 409. The exhaust system on my old '92 had 260k miles and was 14 years old before the rear shock towers rusted out and I had to junk the car. Exhaust was still in good shape. No way aluminized would last that long up here. I remember on our old '90 Taurus one of the muffler clamps rusted off from the pipes, but the pipes were still in good shape. I don't know when most/all OEMs changed over to stainless, but I'm guessing late 80's early 90's. Even the stock exhaust systems on my Saturns are 409.

 

[theterminator93]

That jives with what one of the Lorain assembly line guys (his job for a time was installing the exhausts on our cars) told me years ago - he said they were stainless.

 

[XR7-4.6]

agreed, I can’t speak for earlier models but by 94 it’s definitely 409 stainless. Rotten hardware are maladies to the stock system but the pipes are always solid.

I’ve seen first hand what happens to aluminumized pipes in the Chicago area, they last only a few years.

 

[dDUBb]

What type of welding wire was used ? Thats where it might rust. On the inside.

 

[XR7-4.6]

What type of welding wire was used ? Thats where it might rust. On the inside.

This was the mid portion of my old exhaust, the welds were indeed worse (as you can probably see by the hose clamp patch I made lol) but the previously aluminized pipes beyond were paper thin in places



The magnaflow muffler looks rusty but was 409 stainless and actually lives on on @97 30th s car. Those pipes crumbled to dust as I stuffed them into the garbage can

 

[dDUBb]

It's also evident where the hanger was welded. That would be the result of using non stainless wire on stainless. It will weld, but the corrosion resistance is not equal and paint might take care of that on the outside - but not inside if the welds fully penetrated; and then add some slightly acidic exhaust water.

 

[White Lincoln]

I think this exhaust is stainless as it still looks great after some 30 years.

 

[White Lincoln]

I do have a welding question....

I did a rooky mistake and welded the muffler to the exhaust AFTER tack welding it in place and dropping the exhaust to finish the weld. One mufflers tack welds broke, throwing it out of position. I went ahead and welded both mufflers, but one side is off by more than an inch or so. I need to either:
1. cut a slit, bend the pipe, weld a patch over the cut out,
2. cut the muffler off and use a scrap sleeve to weld it back together after everything is mounted, or...

Any other clever ideas to rearrange the muffler to fit better and weld it back together, after mounting everything?

(yes, there is a lot of grinding that will need to take place to flatten the surface)

 

[Grog6]

When I had the muffler shop redo Lazarus, They told me it was stainless, and their welder wouldn't touch it. They wanted to reuse something, and couldn't. I bought mbs aluminized for the other cars. 2.5 sounds way better on a 4.6 .

 

[dDUBb]

2. cut the muffler off and use a scrap sleeve to weld it back together after everything is mounted

Cut that section out and start over.

 

[White Lincoln]

Cut that section out and start over.

Thanks dDub.

 

[dDUBb]

Just a couple thoughts ..

If the tack weld broke at the pipe end - you're not getting penetration. Need to turn up the heat (amps) The weld bead will stick but it's more like an adhesive bond versus a cohesive bond.

When we tack weld pipes together - usually they are done in parallel and we hammer a wedge into the gap perpindicular to alter the alignment - in other words, the tack welds should have the ability to bend to an extent - they can be broken, and this shoukd happen at the center of the tack, not where the tack is welded to the pipe.

Wire type for stainless .. I'm not sure you're using the best quality wire for the weld you are attempting - what exactly are you using ?

Welding is just like painting .. 80% of the work is in preparation - cutting, chamfering, alignment, cleanup of slag, etc ..choosing coupling fittings that fit tightly over each end is important, anybody can fill a gap but it's not good work practice / means and methods of the trade - I'd rather hammer it flat to make a nice lap joint.

 

[White Lincoln]

Beginners curse. I did not hold the weld long enough to get penetration. The other muffler is fine and the tacks did not break. None the less, I ground down the welds, cut the pipe and made a new sleeve. I am ready to weld once I get the resonators from RockAuto (next weekend) and put everything together, THEN weld. I did some more practice welds tonight and I am getting the nice dime beed now, so it is just practice, practice, practice. And yes, prep is everything. grind and polish the metal down to a shine, put on all your protective gear, make sure there is nothing around that can cause an accident, etc, etc and then weld. Even after a first weld, I have to go back over the area with a wire brush so the weld will flow and heat up correctly.

The wire I am using is made for the Flux Core welder:

VULCAN 0.030 in. E71T-GS Flux Core Welding Wire, 2 lb. Roll​

I think it does a nice job. I can't say too much for the welder, but the equipment is doing what it should. I only wish I would have bought the .035 so it covers more area.

New sleve I made. The black marker marks are where the tack welds will go.

 

[dDUBb]

That wire is OK but not ideal if corrosion resistance was a concern, that and a shielding gas.

Fire Extinguisher .. you probably won't need it as long as you clear the area of combustibles but you should have one on standby.

Your adapter piece still has a wide gap .. as long as your tacks hold, you should be able to make a couple very small relief cuts or pre-cut it before you tack so you can hammer the sleeve flat against the factory exhaust pipe.

.030 wire is best for what you are doing. I'd rather use .025 wire if its on exterior body work and .035 for thicker structural metal like frame / mounting.

..

In welding class for trade school we used to lay down beads on flat metal plate .. hundreds of feet of rows before we started practicing on pipe. Don't get too caught up on "laying dimes" .. every welder has a technique and the whole purpose of practice is to develop muscle memory. Some welders like to zig zag, make circles, figure 8s, etc .. some welders need a beer or two to steady their hand, or use their shaky hand to advantage. The only guidelines we get in the field are weld symbols on a drawing indicating bead thickness or stitch length / spacing.

On that note - the job i finished at the science building involved 3 different weld processes.
Structural / pipe ( carbon steel ) was arc weld with 6010 and / or 7018 rod,
Refrigeration ( copper pipe ) was braze welded with Acetylene torch and silver / copper brazing Rod with Nitrogen purge inside the pipe.
Fume hood extractors ( stainless sheet metal) was done by MIG, stainless .030 wire and a tri-mix shielding gas ( helium, argon and co2 ) .. not cheap, by far the most expensive welds per foot.

 

[Grog6]

My bil was a welder at k-25, a uranium gaseous diffusion plant, as well as other tough stuff.
His daily stuff was 5' diameter pipes that were 2" thick ,lined with monel 1" thick, to keep the fluorine from eating the steel. Stick welds on the steel, which wouldn't touch the monel, then tig welding the monel from the inside. My neighbor was one of the pipefitters that set up his stuff. the residue stuff in the pipes was uranium hexafluoride, which sets skin on fire,lol. depending where it was in the series, it could be weapons grade uranium. They got checked carefully when they crawled out.

 

[White Lincoln]

Excellent information dDub, much appreciated. And yes, I always have a fire extingusher handy, the wife makes sure of it... As for combustables, after the tack welds, I drop the exhaust again and weld the rest of the fitting on a bench / table. Thank you for the tip on flattening the sleeve down to the exhaust. I can make some cuts so it will press down easier. That is how I got the sleeve to fit on the muffler, 4 slots and a hammer. Once I make the cuts, I can simply press it with plyers to get it in place against the exhaust. The heavy work will come with the resonators, y pipe and coupling to the CAT back. Once I get that tacked, it will come off to be welded same as above.

This is better than trade school! LOL

 

[White Lincoln]

My bil was a welder at k-25, a uranium gaseous diffusion plant, as well as other tough stuff.
His daily stuff was 5' diameter pipes that were 2" thick ,lined with monel 1" thick, to keep the fluorine from eating the steel. Stick welds on the steel, which wouldn't touch the monel, then tig welding the monel from the inside. My neighbor was one of the pipefitters that set up his stuff. the residue stuff in the pipes was uranium hexafluoride, which sets skin on fire,lol. depending where it was in the series, it could be weapons grade uranium. They got checked carefully when they crawled out.

Geez Grog... can you speak english?

Impressive to say the least.

 

[Grog6]

google is your friend; I am speaking english, Watch Oppenheimer, most of the stuff in that post is explained in it. You must have went to school in the south. We don't value education here. I taught my nephew algebra, and his teacher said I made him look bad as a teacher,lol. He really didn't like where the conversation went from there.
I went to hs,vocational school, and community college,while working full time,paying my own way to school.
I won't apologize for learning enough to get a good job.

 

[dDUBb]

Geez Grog... can you speak english?

What Grog described is called dual containment .. it's a pipe inside of a pipe. The Monel liner is a high nickel content alloy for corrosion resistance - the steel pipe on the outside is the backup containment if the monel starts leaking.

Watch Oppenheimer, most of the stuff in that post is explained in it.

I must have slept through that part in the 3 hour snooze fest known as Oppenheimer.

 

[White Lincoln]

I won't apologize for learning enough to get a good job.

And you never should. I was just pulling your chain buddy and I did understand what you were talking about. It just sounded several levels above exhaust welding 101 language, hence my poor joke.

 

[Grog6]

The wilcest part of the k-25 plant was when they tore it down, they filled the pipes with foam, cut them up, and buried them in a special landfill. I was told there was enough high enriched uranium to build a few bombs buried in those pipes.
There was two more of those plants; all are shut down now, portsmouth ohio, and paducah ky. Savanna river in ga was a dupe of the hanford plant; they made pu-239.

 

[White Lincoln]

....and they send all the waste down here to Carlsbad, NM (WIPP Plant)