whtas the best way to protect the exhuast pipe ,with paint ! to stop it rusting…
thoughts
…buy a stainless steel one ??
that’s the one!!!
Steel exhausts generally rust due to water in the exhaust; short runs are a sure way to kill an exhaust. Most modern steel exhausts use aluminised steel; mild steel that has been passivated with a layer of aluminium. A lot of these exhausts will also have a chromed tip attached. The grades of stainless steel used in an exhaust will also rust; the higher the grade, the more resistant it is to rusting. So tips are often a much higher grade than the rest of the exhaust. Corrosion on stainless steel is essentially cosmetic. But stainless steel can be passivated as well; sometimes this is called bluing. It can only be done once, when the exhaust is brand new; once the stainless steel has been heated, it will passivate. The finish can be controlled, to an extent, by wiping the metal with a light oil (hence greasey hands will mess up that new stainless steel manifold). Light oil will give a golden finish. Old engine oil gives more of a purple finish. This passivation layer is covalently bonded, so its difficult to clean up a discoloured stainless steel exhaust.
Painting the tip won’t do much to make the steel exhaust more resistant to rusting; the rusting process starts from the inside. Water plus carbon residues, and NOx make for spectacular corrosive acids.
Ok Ok what if I cant afford one!!!
thanks for that detailed reply…
Then you will have to just use an ordinary exhaust and the more you use the car the longer it will last.
As was said above, it is the short and infrequent runs that will help an exhaust rot out.
Having said that, they do seem to last a long time - I’ve had my '92 Eunos for 4.5 years with an unknown age standard exhaust and it’s still going fine after a further 60,000 miles.
You’ll spend more on tyres and patching the odd rusty sill than you will on exhausts.
The exhaust in the foreground was a 18 month old Timax system taken off a Roadster that was a daily driver. Although solid, it didn’t have a great deal more life left in it.
I’m in full agreement with avoiding short journeys to make a standard exhaust last longer. I used to have an MK3 Escort and it’s first exhaust lasted near on 90k as I used the car to blat up and down the motorways chasing “wimen” when a young marine !
when I started using it for comuting a few miles each day it last about 15k before the second one rotted out, it had another rear box before I sold it on…but by then the rest of it was showing signs of rust worm
I bought a Volvo V70 when my “wimen” chasing days were over, and it has a stainless steel system, and near on 14 years later it just looks like it has spots of rust on the outside in places (as described above). it’s great when you don’t have to replace them cause they rot…only replacing them for noise is more fun/ and looks !
Do exhausts last longer these days cause they are built better?..or is it because the cars get up to temp quicker, and journey times are longer cause of jams, so less water left in the system so they rot slower?