Originally Posted by John E
Powder coat is probably fine for an electroforged, welded, fillet-brazed, or internally lugged frame, so it should be fine for your Schwinn. However, I do not recommend it for vintage lugged frames because it will not follow the sharp contours of the lugwork.
Feh. If you're not doing a museum restoration (which, if you're even considering powder coating, you're not) then it's fine. You can always pinstripe the lugs if you want further definition.
http://stockdell.org/biking/bikes/seat_clust.jpg