How to clean out a used exhaust manifold and downpipe?

[mikem]

I have an old tii exhaust manifold that I want to clean out. How to best clean out old carbon? I'm picturing a flexible shaft-ed wire brush that I can attach to a drill and snake through. What's the norm?

I also have a downpipe that I want to clean inside and out. What's the best approach for that? Sandblast, beadblast, otherblast, chemical?

Thanks

[ChuckinNC]

I would recommend bead blasting or sand blasting. You won't be able to get inside the pipes or passages very far, but either with will do wonders on the surfaces you can get to. Be sure to plan on treating the blasted surfaces with some sort of high temperature coating, or they will rust in front of your eyes.

Chuck in NC