[xGE_97]

Hey Gurus,

I have a problem that REALLY STINKS. A crack in the black tank. I would like to do a permanent fix, not a flex seal approach. Does anyone know what plastic was used for 2009 era black tanks? I am also open to experienced perpectives on welding vs solvent glues. Attached is a pic with three arrows showing three streams running out of the crack. The crack is along the passenger side rear aspect of the wastemaster tunnel. I swear you can't smell this just by looking.
Regards,
Bob
   

[Richard]

Bob,

I would contact Newell to see how the fitting was originally installed. It could have been spun welded, or it could have been put on with an adhesive. The attachment method may influence your approach on fixing the leak.

The tank is likely polyethylene. Not much sticks to it long term. And very few non nuclear solvents will touch it. Hence the reason for the spin weld approach.

[xGE_97]

Richard,
Thanks!! I feared it was polyurethane. I was in denial while the gray color gave me nightmares. Speaking of which, Now to find someone that welds polyurethane in place (or maybe a new skill?)
Regards,
Bob

[arcticdude]

Loctite makes a “hard to glue” plastics glue. It works quite well on polyethylene. I used it on my previous coach’s fresh tank drain fitting that was originally spun welded.


It’s this one:
https://www.loctiteproducts.com/products...029X6.html

Lowe’s and Home Depot in my area both carry it. It does specifically state polyethylene in it’s list of plastics it glues.


I did remove the tank and completely break the fitting free (very easily done) to reglue it entirely.

[xGE_97]

Hey Folks!!
Happy Thanksgiving!! Well I followed Richard's advice and contacted Newell. They confirmed the tank is polyurethane. They repair by re-welding, and then re-install the tank.
I'm away from the coach for Thanksgiving. When I get back I'll try to re-weld it in place.
There a couple of ways, based on amount of room around the crack. One is to use a Dremel tool and short piece of polyethelene rod. The process would be to clean the area and grind a groove along the crack, then stitch-weld the crack. The other way involves using a hot plastic welding iron to melt polyurethane rod into the groove.

In any event, practice is required........ after eating turkey......

[xGE_97]

Arctic,

Sorry, I was probably typing when you were responding. Yes, I considered glue but didn't know of anything that really worked on polyurethane. I may patch over the weld with this, after investigation.

[Richard]

Bob, you have used polyurethane and polyethylene in your descriptions. They are anywhere close in chemically or property wise. Can you clarify?

[xGE_97]

Richard,

Thanks. I'm an idiot for not checking before publishing. The tank is polyethylene, per Newell. I just re-checked their email. I don't know if I just can't type or if spell check did something. I should have checked it.

So after lots of research, and not being a chemical engineer, I think I'm going to try welding it. I did not see anything that can glue polyethylene permanently. Do you? Thanks!

[arcticdude]

Bob,

The Loctite glue I linked (https://www.loctiteproducts.com/products...81925.html) states it glues polyethylene.

I used it on my polyethylene fresh water tank to reglue the main drain fitting on that tank. Since it’s the drain and at the bottom of the tank, it’s under the most pressure. It was glued close to 10 years before I sold the coach. It hadn’t started leaking in that amount of time.

[xGE_97]

Arcticdude,

I'll test it out when I get back to the coach. Thanks!