Tank leak (gray)

[AJH]

What is the best thing to use to seal a leak in the gray tank. They are like pin hole leaks on the bottom of the tank. Impossiable to find until the thank is over half full. The weight make them open up. I plan to replace the tank when I get home, but would like to fins a simple patch till then.

[bncinwv]

This may sound a little on the extreme side, but polyethylene tanks usually require a type of plastic welding process to fix holes and cracks. I had a polyethylene float on the boat lift spring a leak and fixed it with a stainless steel screw. I knew where the leak was (a pinhole as you described) and I drilled a small pilot hole through the tank wall and then took a #8 stainless screw and screwed it into the hole (a screw way bigger than the pilot hole). More than a year later, the lift tank is still in use and has no leaks. I would think this would depend upon the thickness of the tank and I do not know how thick the waste tanks on the Montana are. As an addition to the screw fix, I used a cupped stainless washer with the screw and put an o-ring inside of the cupped washer. I am definitely, curious as to how you finally get this resolved, keep us informed.
Bingo

[semperfi66]

I used PC-11 a two part waterproof epoxy. I repaired the black and gray water tanks, they had cracked where the pipe entered the tank. These repairs lasted for years. You can find it in most Ace hardware stores. They also make a PC-7, but I always use the PC-11, it is formulated for marine use. Hope this helps.

[Illini Trekker]

If you have time to wait for shipping try this, Plasti-Mend ABS Plastic Repair Kit for Holding Tank Repair. You can find it at Amazon, maybe you can find something like it local? Heres the link at Amazon.

http://www.amazon.com/gp/product/B00...A1PYRB7RHOFKBG