Leaky Water Pipe

It's an abs drain line and has no seams but is probably leaking at the joint where the two pipes come together. It's probably either a 1 1/2" or 1 1/4" pipe that drains your sink. Not much pressure there and sounds like it's leaked in the past and someone used silicone on it. The best thing to do is to remove as much of the silicone as you can and clean the area well. You should see a nut where the two pipes come together. Try tightening it. If it works great! If not, in an emergency, try "Rescue Tape" which you should be able to find locally at hardware stores. I've never personally used "Eterna Bond " but have heard good things about it. You might try that. If you are in the middle of a blizzard and can't get out of the rv, try any kind of tape you have and wrap it tight. Whatever you do, forget about using the silicone. It will take too long to explain why. In the end, get it fixed permanently and professionally,