Is The Water In Auto Exhaust Acidic?, Would baking soda help my mufler?

It's depressing how automotive mufflers rot away from the inside. They drip water, so I can see this being caused by ordinary rust. But is the moisture that collects in the muffler also acidic?

(I'm installing a new muffler and I'm tempted to put a pinch of baking soda in it!)

Hmm, might be?

Partially burned hydrocarbon residues range from virgin hydrocarbons to all manner of partially broken up, short chain, and rearranged molecules (including aromatic ring structures), with partial oxidation ranging from alcohols to aldehydes to acids (full oxidation being the next step up from acid, which is just plain CO2), and various combinations thereof (ethers, furans, etc.). All these odd compounds are responsible for the peculiar burnt odor of the byproducts, and the tarry to sooty buildup that accompanies such combustion (along with actual soot, which is just as chemically complex, including buckyballs and nanotubes, incidentally).

So anyway, yeah, some base might help to arrest the acidic corrosion, but the fact that you've still got water in there, plus you've added a solid, ionic compound, that dissolves in water, and absorbs contaminants, means it will never be expelled, and it will sit around and cause electrolytic corrosion much faster than distilled (well, very dirty distilled) water will do alone. So I don't think it would be a good idea overall.

Might help to put a "spit valve" on it, maybe just poke a small hole in the lowest corner, small enough that it doesn't let out much noise. Might whistle, though. Even that's probably not so great, because the puncture allows corrosion to get inside, enlarge the hole and so on.

The classic solution for condensation -- just wrap an electric blanket around it!

Tim

I'm thinking about drillin a drain hole. Some mufflers, including this one, come with a drain hole in them. But since this muffler sits an an angle when mounted on the car, the drain hole isn't at the lowest point on the muffler - plus it isn't near the tailpipe end of the muffler, which is what rots through first.

Fit a stainless exhaust. Lasts much longer and probably costs the same given its longevity.

drainer won't help mutch.
the fumes them selfs are corrosing too.
the water vapor + fumes are allso corrosive.
stainless is an option, as allready pointed out.

I dunno what material could be used, probably something better could be found. something epoxy-like in terms of chemical resistance would be good.
but epoxy does not takes that high heat...

leave the new muffler alone .
baking soda ? so , how long would it stay in the muffler ? ... about two seconds .
*poof* ... a white cloud out the tail end .

i have seen exhaust systems that were 20 years old and still in good shape .
the area that one drives in has a bit to do with this ... dry/elevated temperature conditions help out the situation .
if you live in an area that uses salt on the roads ... this really shortens the life of an exhaust system ; from the outside in .

My exhaust system lasted 18 years using 87 octane unleaded.

Been typical of the cars I own, too.

What's the short lived exhaust stuff, besides a manufacturers corner-cutting defect?

I find in general exhausts - even cheap aftermarket - are lasting way longer than they used to, as well as being more service friendly - but 18 years ain't gonna happen in Ontario . However 10 - unheard of in 1985 - is now pretty standard fare.

Yeah, the water is acidic.

Always wondered why diesel exhausts seem to far outlast gas ones though. Maybe just 'luck' but I've yet to actually seen one rotted through.

Drain holes are typical for tailpipe mounted mufflers - i suspect they don't get as hot as their mid body typical 70's counterparts did and so would actually collect a fair bit of with water in time?

Here's me take on mufflers/ Exhausts...

Short runs, and long standing, is what kills the mufflers. If the cabby is standing for some time, Plugging the Exhaust is a good idea, (Try to prevent condensation on the inside) and a quick rub of oil for the outside. medium to long runs that warm up the entire length of the exhaust (evaporates all liquid in the pipes)..

I recently sold my '88 Nissan Sentra Sport Coupé with 300 000 km on the clocks, still with factory (mild steel) exhaust system close to 100%.. (I was 2nd owner, and my Uncle was 1st owner, so i knew the full history on it.)

Daily runners also tend to last longer than the Weekend cruisers.

Then a motor that burns a little (Not Smoky) oil tends to coat the inside of the pipes and stops water to steel contact. Also if your parking area is not flat, park the cabby with the nose up and not ass up. Condensation runs out, not in, as it also tends to build up in the first ~ 500mm of the pipes only.. (any air moving further up the pipes has the moisture already stripped out)..

Having owned 10 Cabby's over the last 20 years (2 or 3 at a time) and many for 5 or more years , apart from Accidental Damage repairs or Modification, I've only needed to replace the Muffler on one vehicle, which was pretty much shot already when we purchased....

farmers. dont get me started on them. as bad as the amish.

its all about the ethanol.