Rust On Mufflers

[Constant Mesh]

On the underside of each muffler on my '04 FJR there are two small parallel rust lines running lengthwise along the sheet metal assembly joint.

Why would rust only occur at the sheet metal joint?

The weep holes on the undersides are open -- condensate is not being retained in the mufflers.

 

[1catquak]

My guess would be that the filler wire used during welding had some contaminents in it. No big deal, it should polish right off.

Besides you can only see this if you are standing on your head, right?

 

[Just Plain Dave]

My guess would be that the filler wire used during welding had some contaminents in it.  No big deal, it should polish right off.  Besides you can only see this if you are standing on your head, right?

Wouldn't that fit into the same category as "Be sure to wear clean underwear in case you're in an accident?"