Originally Posted by
outashape
If you do get S & S couplers, make sure you get a new paint job. I just spray painted the one inch area, and eventually water got in the tube and siezed the bottom bracket. Bilenky said the frame was unsafe and trashed it. I would not do it again. The case, the couplings and the paint job cost a lot of money. I had to pay $75 to fly with Delta. They charge if it is a bicycle, not by size.
I'm not sure what the paint had to do with water getting into your frame? It's possible the water seeped in through the coupler interface (teeth/nut), but unlikely through the junction of the coupler and the frame tube, as that is brazed. It's a good idea to treat any steel frame with FrameSaver, especially S&S-coupled bikes.
That said, I have quite a few steel S&S-coupled bikes, and have never noticed problems with water getting inside. My oldest bike with couplers is an S&S Santana tandem from 2000, and it's still fine despite plenty of rides in the rain.