What causes fouled horns besides snow?

[CSXandNSRailfanner]

Like when you hear a K5HLL or K5LA and it has an odd sound, what causes this? I know the snow can get trapped, but any other ideas? I'm interested.

[SD80MAC]

Bugs, oil, exhaust, water, any random foreign object.

[Saturnalia]

That's gotta take a lot of flies to foul a horn, right?

[hoborich]

Years ago, I had air horns on my truck, and crud builds up over time on the diaphragm. When you compress air, you also compress the moisture in it, and unless you have a water trap on the air line, water can get into the horn.

[EWRice]

Almost all horns have an orifice that is sized to match the horn (usually around 0.100" give or take). Since, until recently, locomotives did not have air dryers/filters all kinds of oily gook could plug up the orifice. Some horn's diaphrams are more prone to wear (nathan m series, early leslies, wabco) while others have used rubber or silicon rings to prevent any metal to metal wear. Tree branches and low garage doors can cause problems too.

[Raildudes dad]

Low garage doors can be extremely hard on them BF was lucky