Help! Temporary repair to grey water tank.

You could coat what you have now with foam. I fixed a gas tank that way. Propped up a sheet of aluminum held about 1 inch away from the surface I was trying to repair. Sprayed foam in between the 2 surfaces and let it cure over night. The repair lasted just over a year, before the foam eventually pealed away. It may be worth doing in your case. I would put it right over the tape. With a long crack like that, the surface is probably not very stable. Foam spray and a sheet of plastic or aluminum should stabilize it, and may seal it off.

BTW: The place to get a replacement tank is http://www.tank-depot.com/product.aspx?id=163. I figure if I could find something to fit my unusual coach, you should have no problem finding one for yours.

I'm done for the time being. Just as I figured, between the danged channel and working upside down in an enclosed space with some very sticky material, I screwed up the repair slightly. In other words it still leaks a tiny bit. However, at about a drop a minute or less, I've put a catch basin underneath and will simply dump the basin when needed. It is a temporary fix after all. When the weather cools down in October, I plan to replace the tank.

I expect replacing the tank will be a problem, I can no longer get an exact replacement and the front of the tank, where it protrudes from the storage space, as well as the associated inlet piping is covered with a few inches of polyurethane foam. Gee, that should be fun to deal with.

Oh well it's at least fixed well enough so that I can use it once again.

Steve

Here’s an update. I’ve received lots of good advice. The fuzzy photo below shows the tank with a red line showing the location of the crack, adjacent to a long channel on the tanks underside. Unfortunately, the cracks location rules out some of the methods people have suggested (I sure wish that channel weren’t there).



What I’ve done so far is to spread the crack and slather it with Gorilla Glue. This is not an attempt to seal the crack but rather to stabilize it so that it doesn’t flex in and out while I’m working on the next step. My next step will be to sand the surface with wet/dry sandpaper and probably rub it with ABS solvent. Then I’m going to attempt to place an Eternabond patch over the crack. Eternabond is so sticky, and I have to place an 18” strip, I’m really concerned about achieving a nice smooth seal where the Eternabond has to go down into that (expletive) channel.

Anyhow so many people have graciously supplied advice I figured I’d tell what I was doing and explain why.

Steve

Road Runners wrote:
I would use plumbers epoxy. It comes as a small round putty like stick. You cut off what you want to use. Then, you work it with your fingers till it is a uniform color. Put that into the crack with overlap. It will harden and may be a permanent repair. I have repaired buckets, plastic fenders, potty water tanks, plastic rings that the toilet hold down bolts fasten too and lots of stuff. I have never had a problem with it once it hardens. You can buy it at home depot and lowes. For your appilication it is better than eternabond.

I tried this stuff on pvc pipe on my lawn sprinklers just for the heck of it on a line that was split.

That was a couple years ago and it's still holding as are a couple more I repaired with it.

Good stuff.

rockhillmanor wrote:
J-B Water Weld

IMHO a miracle! You can patch 'underwater' with this stuff.




http://www.jbweld.com/product/j-b-waterweld/

I have used this product successfully in a variety of applications. I recommend it.

Road Runners wrote:
I would use plumbers epoxy. It comes as a small round putty like stick. You cut off what you want to use. Then, you work it with your fingers till it is a uniform color. Put that into the crack with overlap. It will harden and may be a permanent repair. I have repaired buckets, plastic fenders, potty water tanks, plastic rings that the toilet hold down bolts fasten too and lots of stuff. I have never had a problem with it once it hardens. You can buy it at home depot and lowes. For your appilication it is better than eternabond.

Do this and put EB tape on top of that and I would't be surprised if it lasts forever

I had a crack in my black water tank a few months back and found a permanent solution. Use M5200(it comes in black or white) and spread it all over the crack, then place a piece of hard plastic over that. The cure time is very long for this product, but it is permanent. I've used it to seal holes on boats under the water line! Carefull tho, once applied there's no getting it off again. Big advantage over JB weld is it stays flexable whereas JBW does not.

I agree with trying to find something that will bond to ABS long term as your best choice.

Eternabond is great stuff but don't know how it will react to ABS plastic you might call the manufacture and ask them.

Here is a link with product reviews on repairing ABS tanks.

holding tank repair

Biggest problem with any type of patch is getting it to stick. You tank is made from ABS, which means your plastic pipe solvent bonding chemicals should work better than anything else. Especially if you can find ABS sheeting. The other option is Horrible Freight has a cheap plastic welder and sells ABS rod. To get a true chemical bond, the repair material should be the same as what you are repairing.

BTW: When you got to replace the tank, check out Tank Depot. They have a very large selection of tanks, and will install fittings anywhere you want them. I replaced my grey tank for just over 200 bucks. Initially I patched it, but it had stress cracks all over the lower front edge - ran over a deer.

rockhillmanor wrote:
J-B Water Weld

IMHO a miracle! You can patch 'underwater' with this stuff.




http://www.jbweld.com/product/j-b-waterweld/

I used regular JB Weld on a cracked cast iron water pump for a home water well. Everybody said I was nuts, but it worked. Couldn't even get anyone to weld it. Didn't leak or even seep!