Black Tank Leaking At The Joint

[candace]

Our black tank is dripping where the tank meets the pipe that releases the liquid. I've sanded the area and applied epoxy, but it's still dripping. So, I sanded all of the glue or whatever previous owners used to seal it up and underneath I see silicon. My question: Should I use epoxy to glue on some fiberglass cloth or should I apply some new silicon?

[zero]

Our black tank is dripping where the tank meets the pipe that releases the liquid. I've sanded the area and applied epoxy, but it's still dripping. So, I sanded all of the glue or whatever previous owners used to seal it up and underneath I see silicon. My question: Should I use epoxy to glue on some fiberglass cloth or should I apply some new silicon?

No. The tank is made of ABS plastic and is easy to fix with the correct material. You need some real ABS glue and NOT the so-called universal glue sold for ABS and PVC pipe. You also need a chunk of ABS plastic. You grind up some plastic to make power, mix it with the ABS glue and then just brush it on. Unlike PVC, ABS is "solvent welded." So with the correct ABS glue - it will melt the old ABS and weld new stuff right too it. I've fixed many black tanks. Last one had a huge hole where the RV's exhaust pipe melted right through it. You might have to order in a can of it through a plumbing supply store or maybe find it at a RV place. When I needed it - none of the local building supply stores had it but the RV place did. Do NOT try to use the combo stuff made for both ABS and PVC. IT WILL NOT WORK. You have to use the real ABS glue.

[candace]

No. The tank is made of ABS plastic and is easy to fix with the correct material. You need some real ABS glue and NOT the so-called universal glue sold for ABS and PVC pipe. You also need a chunk of ABS plastic. You grind up some plastic to make power, mix it with the ABS glue and then just brush it on. Unlike PVC, ABS is "solvent welded." So with the correct ABS glue - it will melt the old ABS and weld new stuff right too it. I've fixed many black tanks. Last one had a huge hole where the RV's exhaust pipe melted right through it. You might have to order in a can of it through a plumbing supply store or maybe find it at a RV place. When I needed it - none of the local building supply stores had it but the RV place did. Do NOT try to use the combo stuff made for both ABS and PVC. IT WILL NOT WORK. You have to use the real ABS glue.

Thank you!

[snail powered]

The silicone might cause a problem with getting the patch to stick, it is difficult to remove completely from a substrate. You might want to find a special silicone caulk remover at the hardware store to clean the area with before you attempt the patch.

[jdfrost64]

just shave up a abs pipe and mix it with acetone. till you get the right thickness. then sand area real good . and wipe down with acetone then bush on the acetone abs mixture . that how we fixed them in the rv plant. it melts in better than abs cement

[zero]

just shave up a abs pipe and mix it with acetone. till you get the right thickness. then sand area real good . and wipe down with acetone then bush on the acetone abs mixture . that how we fixed them in the rv plant. it melts in better than abs cement

The ABS cement (the real stuff) IS mostly acetone with a few other "tone" chemicals and works great. Problem is - most places today do not carry it..

[zero]

By the way - I didn't mean to sound like I was disagreeing with the pure Acetone approach. I've done it and found it to work well - along with the ground up ABS to make a paste. Just saying (as already stated) the the real ABS solvent works great. It's kind of misleading to call it a glue because it's more of a solvent that welds the plastic, rather then acting as a bonding agent.

[linda s]

I used the ABS glue and ground up ABS to fix a major hole in my black tank. Still is fine years later.

Linda S

[zero]

The real stuff - the black ABS glue already has ABS particles in it. Adding more makes a large repair a lot easier IF you can find some ABS to grind up. Not always so easy to find anymore since most plastic plumbing is now PVC. "Medium black ABS Cement" contains acetone, methyl-ethyl-keytone, and ABS resin.

[candace]

OK, I tried many things to get the leak sealed. None of them worked, not even fiberglass cloth used with the abs cement. However, I ran over a metal object in the freeway which tore a hole in the bottom of the black tank. I used the advice given here to combine ground up abs plastic with abs cement. It worked great. So, to fix the leak that I still have where the pipe connects to the black tank, I've removed all of the old epoxy and silicon that attached the pipe to the tank. My plan is to use use abs plastic which I sanded down into a powder combined with abs cement to connect the pipe to the black tank. Will this work? Or is this method only for patching holes in the tank itself? Both the pipe and the tank are made of black abs plastic. It looks like originally the pipe was connected to the tank using epoxy. Then a bead of Silicon was added around the edges. Should I do that instead?

[linda s]

No only use ABS stuff. The silicone was what caused the problem in the first place. Someone must have replaced the pipe with the wrong product.

Linda S

[candace]

I'm so happy! It worked! I made a powder out of a little piece of abs I found at home depot using sand paper. Mixed it with abs cement. I found the best way to do this was to take a little bit of abs cement from the can on the little brush that comes with it and dab it in the abs powder. Then apply to area that needs repair. repeat as needed. I also tried mixing it all together at once but found it dried more quickly than I would have liked doing it that way. Black tank no longer leaking! Thanks for your help, forum

[Derek up North]

Though it's no longer leaking, you might want to continue adding more layer to prevent it failing again from vibrations and road shock. Just a thought.