Gray Tank Repair

[SuziesMontana]

Howdy,
Long time fan of the forum as I have learned full time RV ain't for sissies. Learned a hard lesson and now I'm trying to fix it and want some feedback.

About 4 years in we found out the kitchen tank was not draining well and did not realize we should have been treating it. Not knowing where the issue was I resorted to the plunger. I know y'all are and yes it did not work. I finally found the courage after researching this forum to open up the underbelly and find the gate valve. After multiple hours of clawing and dry heaving I got all the caked up grease out of the tank.

However, a new issue raised it's head. The tank now was compromised at the top (likely the plunger) has blown the seal. I attached a pic from my scope. I must have broken the seal during the misguided plumbing hack. So for the past three years we have been cognizant that we need to drain the tank twice a week or it will start overflowing out the top of the tank.

I really want to figure out the fix now. I don't really want to cut open the whole underbelly and drop the tank, however, I am eyeing unhitching one corner of the support bar, lowering the tank down a couple inches so I can more easily access the pipe. I figure I need to either pull the pipe and replace the seal or use a compound to create a seal around the pipe at the tank. Like from some JB Weld to seal up the entire connection.

I'm looking for anyone experienced to give me a:

Go For It!
Do it but...
DON'T DO IT!!!

Any feedback is appreciated.

 

[Carl n Susan]

Other have had this problem. Here are a few, of the many, discussions on cause and repair. Some have had success with ABS glue and others have replaced the tank. YMMV.

Black tank leak issue

2012 3100RL I have been chasing a black tank leak when tank is almost full. After removing the underside I think I have found the issue. The tank seems to be two piece. A contoured bottom and a flat top. The leak is coming from the seam in the front of the tank just above the flush hose inlet...

www.montanaowners.com

All tanks leak

i don't think I've ever seen this problem before. I have a 2014 3402RL and all my tanks , black and gray, are two piece tanks. the top is actually like a lid that is glued on. All of my tanks leak where the top is glued on. i have to make sure that i empty my tanks before they get full or yuk...

www.montanaowners.com

Black tank failure

While using the Camco Blaster Pro tank flush adapter this morning, I experienced a major problem. Several minutes into the second filling, the black tank fractured its lid and water flowed everywhere. I removed the unit’s chloroplast underbelly and could reach up and lift the damaged section of...

www.montanaowners.com

 

[rickybobby]

My buddy had a crack in his fresh water tank and a leak around top of one baffle. He bought a plastic welder with appropriate rod for the tank and we pulled tank, welded it filled with water and it didn't leak. Reinstalled.

 

[mlh]

O live on a farm. I spray weeds on our farm and two other farms. I carry the sprayer on the front end bucket. It bounces around and occasionally falls out of the bucket. This is much worse than happens to a camper tank. Camper tanks and my sprayer tank are made of the same material. I’ve busted several holes in it. I fix it with silicone like they sell at the hardware store. I’ve never had a fixed place to repair again.
I just put a coat of silicone on the split about a quarter of an inch thick on it. A better way would be to put the silicone on and a piece of plastic over it. The bottom of a 5 gallon bucket would work. The advantage of silicone is it’s very flexible. The plastic patch would be additional insurance.
Lynwood

 

[Mark77]

For an ABS tank and fittings, many of the traditional sealants will not work.

What I did when I had a tank crack on top, near the edge where it supported (likely from a previous owner traveling with the tank to full) was buy a can of ABS cement and a cheap ABS fitting and ground the fitting into a lot of shreds. Then I mixed up a past using the cement and the ground up fitting and used a wood shim to spread it over the crack, essentially welding it back together. I think I put 2 or 3 coats on it. Has worked so far.., going on 8 years now.

NEVER travel with heavy wastewater tanks.

 

[SuziesMontana]

Thank you all for the varied replies. I do doubt my welding skills though. I like the JB Weld compound idea and that seems to be a common theme for others mentioned in the other topics referenced. That is actually the route I think I'm going to try first. At least now I know there are no people adamantly saying it should not be attempted. I'll take my jacks and support the tank and lower it just enough to make the area assessable for the cleaning and sealing. If it goes horribly wrong or right I'll let you know.