Fresh water leak at drain fitting

[RFP]

Well, Dang!

I've got a rapid-drip leak in my fresh water tank; obviously from the dtank's drain fitting (see photo). Is the tank-colored fitting actually 'glued' to the tank, or is it screwed into a treaded boss in the tank wall?

I'm thinking I'm proably looking at replacing tha %^%#@#% tank.

What say y'all?

[richard5933]

Are you sure it's between the fitting and the tank? Not between the brass and the fitting?

Looks like it might have been spin welded to the tank.

Tanks can be repaired, fittings replaced, and even cracks heat welded. All depends on where exactly the leak is and the condition of the tank.

[sheriff1]

Spin welded fitting. I’ve had 2 fail. Find someone who does plastic welding. You will probably have to remove the tank.

[GCinSC2]

If you’re facing a nasty drop the tank repair, care to try an alternative as a what have I got to loose?

Pig Putty Epoxy

I’ve used it on a few things enough to impress me that it’s worth a try. If you can get your fingers in and around the joint that’s a big plus. I’d just make sure the area is super clean.

Ok one thing you’ll need to look at is it compatible with potable water.

[RFP]

Originally Posted by richard5933

Are you sure it's between the fitting and the tank? Not between the brass and the fitting?

Looks like it might have been spin welded to the tank.

Tanks can be repaired, fittings replaced, and even cracks heat welded. All depends on where exactly the leak is and the condition of the tank.

Thanks, Richard. I'm sure the leak is right at the tip of the arrow in my photo. If I "push" on the connection increases the leak. I think I'm doomed ;-(

Robert

[JCWDCW]

If you go the epoxy repair route…. and that is certainly worth a try, I wouldn’t worry about the potable water compatibility
Cured epoxy is pretty inert and tha contact with water is very minimal in a small crack
JCW

[fran&frank]

I had a similar leak and bought an inexpensive plastic welder at Harbor Freight and was able to fix it by just building up plastic around it with the welder. Just be sure to get the tank empty with no active drip before welding it.--Frank

[richard5933]

I've also done some small repairs in a pinch with a clean (new) soldering iron tip heated just enough to get the plastic to melting temp. Helps to have a piece of extra plastic of the same type on hand to work into the crack as it heats. In my case I was able to shave a little plastic off a factory seam which had some extra left from the tank production and used it to make the repair. I scraped the area clean with a razor and carefully softened the edges of the crack with the iron's tip, then melted the extra plastic into the crack to fill it evenly. The stuff is pretty easy to work with if you keep the temp low and don't burn it.

[ROBERT CROSS]

Originally Posted by RFP

Well, Dang!

I've got a rapid-drip leak in my fresh water tank; obviously from the dtank's drain fitting (see photo). Is the tank-colored fitting actually 'glued' to the tank, or is it screwed into a treaded boss in the tank wall?

I'm thinking I'm proably looking at replacing tha %^%#@#% tank.

What say y'all?

I would clean well and use Marine Tex.

The MT Website

Bob
🇺🇸

I used it on this repair 14+yrs ago. The fitting was cross threaded during the build. JC sent me the part...I still have it.

[RFP]

Thanks all, for your thoughtful responses. While my first thoughts tended toward one of the many 'epoxy' products, I can't find any that are suitable for polyproplyne... it seems that nothing will reliably stick to it.

Welding is an interesting option. of course limited access complicates the job and limits the options pretty dramatically.

If I could just 'break' off the original bung (fitting), and if there was a 1" hole, I could use one of these clever things: https://usi-rv.com/category.sc?categoryId=4 Gee, that's a lot of "buts" and "ifs." Breaking off the old bung would likely fracture the surrounding tank wall anyway :-(

Does anybody know the wall thinkness of the fresh water tanks used in late model trailers (2014 to be specific)?

[Okiegent]

Originally Posted by RFP

Thanks all, for your thoughtful responses. While my first thoughts tended toward one of the many 'epoxy' products, I can't find any that are suitable for polyproplyne... it seems that nothing will reliably stick to it.

Welding is an interesting option. of course limited access complicates the job and limits the options pretty dramatically.

If I could just 'break' off the original bung (fitting), and if there was a 1" hole, I could use one of these clever things: https://usi-rv.com/category.sc?categoryId=4 Gee, that's a lot of "buts" and "ifs." Breaking off the old bung would likely fracture the surrounding tank wall anyway :-(

Does anybody know the wall thinkness of the fresh water tanks used in late model trailers (2014 to be specific)?

On my 83 tank I took the old fitting out and used a tapered pipe thread. it worked like a charm still holding 10 years later. I take it in and out every time I drain the tank. As a side note I have found that 2 part epoxy for plastics from Home Depot will fix and bond to about any plastic or resin product. You also could possibly drill it out and put a fitting in with a gasket on out side. Tighten it down and see if it works.

[Okiegent]

I found these on the internet.

https://www.plastic-mart.com/category/52/gaskets

https://www.amazon.com/Plastic-Tank-...+Tank+Fittings

[retirenow]

I had almost the same exact issue with our 2014 23' Flying Cloud. Someone here suggested I used JB Weld Marine epoxy. I cleaned the fittings well with degreaser, and sanded it to give a rough surface, and re-cleaned. I was difficult to get to but with patience I got it cleaned and prepped. No leaks in the 2 years since it was done. No way did I want to drop the tank. In trying to figure out why this happened, I discovered one of the straps holding the tank to the frame had one end not even bolted to the frame. The hole was stripped out. So, the next larger bolt size fixed that problem. Not sure if that was the cause, but the tank could have been flexing. Either that or it froze and cracked.

[RFP]

Well, if the tank has sufficient wall thickness (1/8" or more), one of these could be a viable solution:

https://m.youtube.com/watch?v=EwNZWr00JXU

These fittings are spin-welded to the tank, and apparently are a weak link.

I really don't mind dropping the tank, I just want to do a repair or replacement that won't need to be "fixed again" after yet another failure.

[richard5933]

Originally Posted by RFP

Well, if the tank has sufficient wall thickness (1/8" or more), one of these could be a viable solution:

These fittings are spin-welded to the tank, and apparently are a weak link.

I really don't mind dropping the tank, I just want to do a repair or replacement that won't need to be "fixed again" after yet another failure.

Seems like a nice option.

Spin welded fittings usually outlast the tank if they are done correctly. Unfortunately there are many ways to install them other than correctly.