High temp silver discoloring

[sgunn911]

That's funny, because it is from Caswell and they said to put it on the forum and offered no help.

[bzer1]

To be honest I think your solution is to attack it from the inside. If I remember correctly these heli mufflers are baffels not packed with sound deadeners. You might want to contact the manufacturer and verify. I would use something like a techline thermal barrier (CBC2). What you might be experiencing is wasted fuel burning in the exhaust...very common on R/C helis and planes. Due to the short exhaust manifold the still burning fuel enters the manifold and because it's so short it doesn't have enough time to dispurse the heat. I would try that first. Another problem is that the oil content in the fuel is very high so the thermal barrier might help direct that out as well. I'm wondering weather the exhaust is also settling on the coating and burning in. Hope this helps.

[DALE]

What temp did you bake it on at and for how long?

[Popeye]

Looks burnt to me. Air cooled 4 stroke EGT would be around 1500F.

[Stytooner]

I don't know very much, but I have heard about ceramic coatings for headers. How is this done? What would the color choices be? Just throwing in another monkey wrench.

[viper56]

Lee,

Ceramic coatings are liquid and applied with a gun. They are usually cured at 500 degrees for an hour.

Jim

[Stytooner]

Thanks Jim. I rekon thats a whole nuther ball game.