Exhaust cleaning

What would be the best way to remove all of the corrosion from my exhaust? I was thinking of shot blasting all the rust off and then having it chromed (will look good albeit for a short period of time....). I guess if it is stainless then I could shot blast it and the simply polish it to get it shiny again???? Or are there better suggestions?

 

[David Morton]

If its magnetic and corroded, use it as a pattern. If it's stainless and yet still corroded, again use it as a pattern - probably because it was made of cheap SS (which can corrode with heat and time).

 

[Mark Worthington]

I would recommend having it media blasted and, if the corrosion is not too bad, sending it out to be ceramic coated.

 

[wpeter]

I agree with Mark, ceramic coating is the best solution. They will blast them when they are coated, inside and out. Stainless steel exhausts WILL CORODE. Even the best SS is suceptable to chlorides, ie sodium chloride, chlorine etc. It usually starts as a pin hole around a particle of steel and progresses from there. Never use a mild steel brush on SS.When it is welded the composition changes and that is usually the first place where the corrosion starts. Before it is put into service, it should probably be passivated with a mild acid to put a "skin" on the surface. It will take away the pretty shine.
Bill

 

[John Fitzpatrick]

[ QUOTE ]
I agree with Mark, ceramic coating is the best solution. They will blast them when they are coated, inside and out. Stainless steel exhausts WILL CORODE. Even the best SS is suceptable to chlorides, ie sodium chloride, chlorine etc. It usually starts as a pin hole around a particle of steel and progresses from there. Never use a mild steel brush on SS.When it is welded the composition changes and that is usually the first place where the corrosion starts. Before it is put into service, it should probably be passivated with a mild acid to put a "skin" on the surface. It will take away the pretty shine.
Bill

[/ QUOTE ]

Bill-- you're absolutely right on that! SS corrodes more slowly than carbon steel in most environments, but I've see it literally crumble away in the presence of hydrogen sulfite and brine. And the higher the temp, the worse it gets. I would think that pitting and galvanic are probably the more troublesome SS corrosion forms in automotive applications, but my experience is in natural gas transmission, and I could be off on that one. For those interested, there's a stratghtforward discussion of corrosion of stainless steel, both austinitic and ferritic, at the National Institute of Standards and Technology site at

[url="http://www.azom.com/details.asp?articleID=1177#_Passivation_and_Pickling"]http://www.azom.com/details.asp?articleID=1177#_Passivation_and_Pickling

"If stainless steel does become contaminated by carbon steel debris this can be removed by passivation with dilute nitric acid or pickling with a mix of hydrofluoric and nitric acids." Just be sure the nitric is very dilute and rinse like crazy when you're done...it's nasty stuff.
John