Powdercoating an expansion chamber

I'd worry a little more about the powder melting than I would about it staining.

If I recall correctly(50/50 chance ) these also changed colors a little from the heat.

I would suggest that powder coating a pipe is only for show and it will not last under the heat of the exhaust. I would suggest doing a ceramic coating and it will last almost forever. It looks a bit like chrome and will last and not stain.

Paw Paw

This plus you will get the proper prep needed to make sure it is all the way clean.

Powder coating a pipe will work fine as long as you use hi temp powder. The resultant coating will look
like your OE pipe but will be much more durable. The hi temp powders are good to 1200 degrees just
like header paint. Any finish will get stained from cooked on mud, and some finishes are easier to clean
than others. I haven't powder coated an aftermarket unfinished pipe, but I have powder coated OE
pipes with good results.

If you're interested, here's a link to a site that sells the powder:

http://www.powderbuythepound.com/HIGH_TEMP_FLAT_BLACK/

Ceramic and other types of coatings are good as well (I have ceramic coating (Nitroplate), on the headers
on my truck because it keeps the heat down in my engine compartment), but it will cost you quite a bit more
than the $28 you'll pay for hi temp powder.

Personally, I would run an unfinished pipe. They are easier to maintain than a painted pipe (5 minutes with
a Scotchbrite pad and WD40). Of course there is always plated pipes if you are into "chrome" on a dirt bike.

dogger