Fresh water tank leaking

So I finally got around to attempting a fix for the leak around the fresh water drain flange. Thanks for the discussion here, I would have slapped some silicon on there without all of the thoughts you all provided. The flange area is an obvious weak point so I didn’t want to spend big bucks on a fix considering the future likelihood for failure.

I decided to go with JB WaterWeld for three reasons...1) it’s drinking water safe, 2) it’s low cost ~$5, 3) application fits my skill set as a DIYer.

What’s the worst that could happen?.. I can always buy a new tank.

Here’s what I did. Cranking the tongue all the way up gave me enough room to slide under. Then I drilled stop holes on either end of the crack to prevent spreading. Next I took a drywall saw and sawed along the crack to increase the width (gap) careful to only cut on the pull stroke to prevent getting plastic shards in the tank. The idea was to create a small gap that the putty could fill instead of just spreading it on the surface. Finally I pushed the putty into the crack and spread it around the area a bit to get full coverage and applied a little upward pressure with a reversed quick clamp to keep alignment between the sides of the cracks as it was sagging a bit before.

So far so good, it held water overnight. We’ll see what effect time and usage have.

In the pics below you can see the crack with drilled holes, the texture of the putty and the clamping arrangement.