Exterior fresh water tank leak

[55 Nomad]

I went to fill my exterior fresh water tank and noticed a small leak. It is streaming out of a small crack at about the 9 o'clock position above the drain. It is hard to see but is a light tan color about 3/8" long. It was not leaking last month before our 1100 mile trip. Has anybody had a similar leak and what did you do to fix it? I was thinking of drilling a hole at each end of the crack to stop it from growing. I am not sure what to use to seal it so it won't leak.

[GroupB]

I would drill and tap a hole (10-32?) at the end furthest from the drain pipe. It looks from the picture that the close end is at the thread in the tank. If so, I would leave it alone.

Then I would clean the surface, apply some epoxy or urethane sealer to the area, and cover it with a piece of flat metal drilled for and secured with a stainless screw in the tapped hole, taking care not to strip the plastic threads.

[mloganusda]

Go to a body shop as they deal with plastic all the time. They will know what to use to seal/repair the plastic tank. IMHO, do not drill into the tank as this will cause more problems down the road.

[Bud]

I saw this guy on tv, he said that Flex Seal would fix anything like that.

[avanti]

Originally Posted by Bud

I saw this guy on tv, he said that Flex Seal would fix anything like that.

Just to be sure, I would confirm that claim with Some Guy on the Internet.

[Bud]

Originally Posted by avanti

Just to be sure, I would confirm that claim with Some Guy on the Internet.

avanti, I tried that but even after 25+ years of internet, well ymmv......

Bud

[GeorgeRa]

The tank looks like olefin plastic (polyethylene, polypropylene…); they are resilient to any glue. My suggestion would be a well welded bead of an olefin welding rod. Most plastic tanks manufacturers have plastic welding equipment for plastics. Doing yourself with a hot air gun can be done with some practice.

https://www.harborfreight.com/plasti...ure-96464.html

[55 Nomad]

Update, I took the drain fitting out today and the crack is the shows in the threads. The picture although not very clear you can see a light color tan line is the crack at the 9 o'clock position. Not sure what to do at this point but GeorgeRa seems to suggest a good fix. Thanks to everyone who helps.

[GeorgeRa]

Drilling current bulk head fitting and welding a new one could be your best option. Search locally for a "Plastic Welding" shop.

[booster]

Originally Posted by GeorgeRa

Drilling current bulk head fitting and welding a new one could be your best option. Search locally for a "Plastic Welding" shop.

Yep, and it will be probably be an easier, more reliable, repair than trying to route out an old dirty crack and weld it.

[55 Nomad]

I fixed it my self. Purchased a plastic welding hot iron kit from Harbor Freight. Removed the drain fitting, wiped the area clean with rubbing alcohol, ran a scribe along the crack then 220 grit sand paper in the crack and around the crack, again cleaned area with rubbing alcohol. Using the iron melted the crack closed and filled the repair with plastic welding rod. I filled the tank full and so far after 4 days no leak. Thanks everyone for your help.

[themexicandoctor]

Four Syllables: Hallelujah!

(with zero religious inference)