Yup, it still leaks - RO tank plumbing fail

Calm Blue Ocean

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It's had silicone, JB Plastic Weld, instant glue...still drip drip drip. The JB Plastic Weld didn't bond with any surface and really just redirected the leak. What I'd really like to do at this point is find a way to cap the whole thing off and possibly start over with a Uniseal (but maybe that's not appropriate here either). And of course if I knew how to cap it off then I'd probably know how to stop it from leaking in the first place! The water tank is one of these with built in fittings but I'd say this particular fitting is toast now. Clearly I know nothing about plumbing and made the assumption that this was a simple straight forward thing (just screw a spout on right???). Is there any recovery from this mess? What parts to I need and where do I go from here?

leak.jpeg
 

theatrus

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Is the fitting removable? I've found a lot of plastic tank fittings aren't really sized correctly for NPT (usually, too big and the plastic is too soft). NPT requires a taper fit to seal and should never "bottom out" into the fitting. which these are prone to do. You can always try to salvage by packing it with a bunch of tape but its not a great solution.

Drill it out. Go to McMaster.com and splurge on a proper bulkhead, and toque it down to the tank. Good bulkheads are reverse threaded and can carry an amazing load (way better than the thin aquarium ones), and have a huge seal to avoid problems.
 

laverda

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Replacing the bulkhead should not be hard once you remove the old one and the glue. My guess is you will have to cut the bulkhead apart at this point. You should not need to use sealer of any type on a bulkead. The seals do get old and hard with age. Bathtub seals are available at Home Depot and other places when that happens. The seal always goes againt the flange of the bulkhead. For that application I would suggest a heavy duty bulkhead. Some aquarium suppliers stock them. I would not use a uniseal for this application as turning the valve on and off will possibly cause it to work out over time.
 
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Calm Blue Ocean

Calm Blue Ocean

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Drilling it out and installing a proper quality bulkhead sounds like the best answer.

This is what the built in fitting looked like before I destroyed it. I suspect it was indeed a case where the PVC was much harder than the plastic, probably not sized right, and simple mistakes stripped the threads. Many bandaids were not going to fix it. Total DI Wrong.

Glad I went with an AIO for my fish tank and not a traditional sump. Plumbing is clearly not my thing :p

fittings.jpg
 

ThePlummer

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If what's under all that gobbeldegook is a bulkhead, you never try to thread a female fitting over the hub, those threads are cut specifically for the nut that tightens down the bulkhead. There are either threads on the inside of the bulkhead that a male threaded adapter screws into or it's smooth and it's a slip glue fitting.
 
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Calm Blue Ocean

Calm Blue Ocean

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If what's under all that gobbeldegook is a bulkhead, you never try to thread a female fitting over the hub, those threads are cut specifically for the nut that tightens down the bulkhead. There are either threads on the inside of the bulkhead that a male threaded adapter screws into or it's smooth and it's a slip glue fitting.

This is how the tank came from the factory:

tank.jpg


This is what I tried attaching to it:

fitting.jpg


It actually held for a while but I guess repeated wiggling from turning it on and off wore it out and it started to leak. The inexperienced solution was not only a failure but probably more complicated than doing it right in the first place.
 

ThePlummer

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Ok, disassemble the nipple out of the tank and inspect for cracks.... I suspect the tank is cracked along the threaded portion. If that's the case, IDK what to tell you other than contact the manufacturer and see what they recommend for glue/epoxy repair.

If you don't see any visible damage, go get yourself from a reputable plumbing supply house, stuff called "Mega Lock", AKA Leather lock. Do not use thread tape, all that will do is swell the fitting and cause leaks.

On second thought, call the manufacturer or look in the instructions and verify that the tank is threaded with 'pipe threads' and does not require some type of machine thread w/ rubber grommet instead. The nipple you are using is a tapered pipe thread, and the corresponding tank threads must be tapered also to seal that kind of joint.
 
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Calm Blue Ocean

Calm Blue Ocean

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On second thought, call the manufacturer or look in the instructions and verify that the tank is threaded with 'pipe threads' and does not require some type of machine thread w/ rubber grommet instead. The nipple you are using is a tapered pipe thread, and the corresponding tank threads must be tapered also to seal that kind of joint.

Sounds like good advice. I'll see what they say and go from there!
 
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Calm Blue Ocean

Calm Blue Ocean

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Just to follow up, sounds like the fitting that I'm looking for is a .5" NPT Male Thread. May seem obvious, but if I'd gone straight to the manufacturer I would have seen that they sell complete plumbing kits (for RV installation) with a detailed parts list. Beginner mistake thinking all threads were the same. Thanks for all the input!
 

samnaz

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I’ve been thinking about getting one of these tanks. I’ve wondered about the included bulkhead and whether or not it would hold up over time, or if it should be replaced with a different bulkhead. What’s your plan to remedy the leak? Keep us posted.
 

ThePlummer

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Just to follow up, sounds like the fitting that I'm looking for is a .5" NPT Male Thread. May seem obvious, but if I'd gone straight to the manufacturer I would have seen that they sell complete plumbing kits (for RV installation) with a detailed parts list. Beginner mistake thinking all threads were the same. Thanks for all the input!
Ok, NPT means National Pipe Thread, which means that they are tapered. So, the nipple you were using should have worked.

Now on to figure out why it continues to leak. Back to the 'Mega Lock' thread sealant. I would also consider putting a wide hose clamp on the female fitting, and tighten it as tightly as you could, not with a screw driver, but actually a nut driver. If there is a tiny crack in the tank fitting, this clamp most likely would squeeze it together tight enough for the nipple to engage with the sealant and it'd do it's job....

Let us know if that works.
 

ColdOceanReef

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My Poly tank came similar to yours. I had leaks issues as well. Thought, I added a seal bulkheads and uses 3/5 male threaded
371E0E96-67C7-4435-A852-957D12E41BE8.jpeg
 
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Calm Blue Ocean

Calm Blue Ocean

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Ok, NPT means National Pipe Thread, which means that they are tapered. So, the nipple you were using should have worked.

Now on to figure out why it continues to leak. Back to the 'Mega Lock' thread sealant. I would also consider putting a wide hose clamp on the female fitting, and tighten it as tightly as you could, not with a screw driver, but actually a nut driver. If there is a tiny crack in the tank fitting, this clamp most likely would squeeze it together tight enough for the nipple to engage with the sealant and it'd do it's job....

Let us know if that works.

This is good news! Sounds like a fix I can get from the local hardware store instead of combing Amazon or heading to the city (about 140 mile round trip). Hopefully in the end it will even look like I know what I'm doing. I really appreciate the help.
 
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Calm Blue Ocean

Calm Blue Ocean

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I’ve been thinking about getting one of these tanks. I’ve wondered about the included bulkhead and whether or not it would hold up over time, or if it should be replaced with a different bulkhead. What’s your plan to remedy the leak? Keep us posted.

The tank fits perfectly in the gap between my washing machine and utility sink so I'd really like to find a way to make it work. Hopefully the fix suggested above does the trick!
 
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Calm Blue Ocean

Calm Blue Ocean

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Just wanted to update. I finally made it to the hardware store and we're now 3 days leak free! The epoxy came off perfectly clean since it hadn't managed to bond to anything. I sealed the threads properly and added a hose clamp. I'm very happy to have my tank full of water again. Thank you for the plumbing lesson!
 

ThePlummer

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Just wanted to update. I finally made it to the hardware store and we're now 3 days leak free! The epoxy came off perfectly clean since it hadn't managed to bond to anything. I sealed the threads properly and added a hose clamp. I'm very happy to have my tank full of water again. Thank you for the plumbing lesson!
Anytime.... Been a professional plumber for over 20 years now.... I'm glad I could help, and check out my DIY tank build, it might give you some ideas in the future.
 
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