Got a hair line crack between the fresh water intake pipe and the air inlet pipe. This is to the top edge and the end side of the tank. Crack is about one inch long, and only leaks when I fill it real full, or right up to the top of fill inlet pipe. Any idea's on how to fix this with some kind of glue or contact cement. I'm not quite ready nor do I want to buy or install a new water tank at this time. When the water level is about two inches down or below the inlet pipe it don't leak anymore. I have it somewhat apart at this time, and would like to try and get it fixed if possible. Thanks waam Holland, Mich. P.S. This is a kind of white plastic fresh water tank. 40 Gal.

 

I would think that you could put a little marine type epoxy on it and seal it up. I doubt that you would get any sort of caulk or silicone adhesive to stick to that kind of plastic. I am aware of the type of plastic, but never have tried to get anything to stick to it. JB Weld may be one alternative also.

 

Found this on the web. Kind of pricey for a couple of tubes of epoxy though:

Plastic Tank Repair

Another option, probably cheaper is the JB Marine Weld:JB Weld

 

The "Plastic Tank Repair" kit works good. Made a happy camper out of me when I used it to repair a gray water tank crack in my 5er.

 

Before you try and repair it I would drill a small hole at the ends of the cracks so the crack won't spread further after the sealer is on it.

 

Not sure if the plastic is the same as the waste tanks. We had to replace a friends waste tank a few months back. And the stuff he was given in the kit was the glue and primer for regular plumbing pipe. Try taking alittle piece of plastic and glue it over the crack.

 

Might look into a 'plastic welding kit' online. Places sell plastic welding rod plus a welding iron, but you will notice it's just a glorified 40 watt soldering iron! I think those tanks are polethylene, same stuff as milk bottles and water bottles from the super: hint hint.... got a soldering iron and an empty water or milk jug? I agree with drilling a couple of stress relief holes at ends of crack before welding.

 

Thanks for all the help. I ended up buying J-B water weld, you have to knead in for uniform color, it goes quick. I sanded by the crack and scraped it with a sharp knife. Applied the weld, its rock hard in 20 min. No more leak. Thanks again. waam Holland, Mich.