When I worked in a muffler shop it was common to drill a 1/8" hole at the low point of a muffler or tailpipe to drain off condensation if we expected a lot of stop and go driving. I might add that on my own pickup truck when I put on a complete exhaust system, I painted it with 2 coats of aluminum stove pipe paint I happened to have sitting around. In 10 years it did not get a speck of rust on it and continued to work perfectly. The first 2 or 3 feet next the manifold turned dark gray from the heat but that was all. If you want your exhaust to last I suggest painting it with heat proof paint. Black barbecue paint is tough as hell if you don't mind a black exhaust.
The Jalopy Journal
