I blew up my black water tank today!

[Mic]

Originally Posted by jasin1

Keep us updated..maybe you could rig up a portable black tank tote to use while your repairing it ? Unless you have nearby facilities you may be able to attach some flexible hose from the tote to what ever pipe is left from the toilet.

Need to closely watch it though for overfill

or coudl one temporary replumb the toilet into a gray tank ...until project done.


bigger and has sensors as to a tote ????

[jasin1]

Yeah probably a bad idea to rig up a tote..don’t want another environmental hazard on your hands.

Sounds like you had a plan so might as well stick to it

[skids]

Originally Posted by jasin1

Yeah probably a bad idea to rig up a tote..don’t want another environmental hazard on your hands.

Sounds like you had a plan so might as well stick to it

For short term, just use the campsites crapper.

[jasin1]

Originally Posted by skids

For short term, just use the campsites crapper.

Couldn’t remember if they were boondocking or not

[bikemechanic53]

Yes we are boondocking.

I have replaced the tank and plumbed the 3 connections. The new ICON tank is almost identical to the old one. The old tank did indeed slide out once one of the 2 supporting beams was removed.

The job went OK and was a PITA but nothing impossible. The only change to the original setup was the tank drain pipe. I put a rubber/clamp coupler in the drain pipe, downstream from the valve. Only way I could figure out how to get the valve and pipe all back together.

I've tested the tank and the new fittings. Nothing leaking yet. It took me a total of about 8-9 hours of (relatively unpleasant) work and a little over $300 to fix my screwup. Could have been worse.

[chuckster57]

Originally Posted by bikemechanic53

Yes we are boondocking.

I have replaced the tank and plumbed the 3 connections. The new ICON tank is almost identical to the old one. The old tank did indeed slide out once one of the 2 supporting beams was removed.

The job went OK and was a PITA but nothing impossible. The only change to the original setup was the tank drain pipe. I put a rubber/clamp coupler in the drain pipe, downstream from the valve. Only way I could figure out how to get the valve and pipe all back together.

I've tested the tank and the new fittings. Nothing leaking yet. It took me a total of about 8-9 hours of (relatively unpleasant) work and a little over $300 to fix my screwup. Could have been worse.

Feel free to come by the shop…your hired!!!

Glad you got it all fixed.

[jasin1]

Originally Posted by bikemechanic53

Yes we are boondocking.

I have replaced the tank and plumbed the 3 connections. The new ICON tank is almost identical to the old one. The old tank did indeed slide out once one of the 2 supporting beams was removed.

The job went OK and was a PITA but nothing impossible. The only change to the original setup was the tank drain pipe. I put a rubber/clamp coupler in the drain pipe, downstream from the valve. Only way I could figure out how to get the valve and pipe all back together.

I've tested the tank and the new fittings. Nothing leaking yet. It took me a total of about 8-9 hours of (relatively unpleasant) work and a little over $300 to fix my screwup. Could have been worse.

What did you find with the old tank? Was it split?

[ssthrd]

Good job fixing your tank!

Too late for you, I guess, but maybe not for others who may have to replace a tank.

I did mine a little different, but ended with the same result. I cut the inlet pipe and the vent pipe in the basement and dropped the whole thing after I unbolted the dump valve. put new pipe stubs in the tank cut to length and used couplings to put it back together. I didn't tighten anything until the dump valve in place and bolted up so that I had some play to get the dump valve in without "fish mouthing" a gasket.

I also put a couple of ratchet straps under both the new tank and the black tank attached to the trailer frame on both sides for a little insurance.

I was lucky that mine was the grey tank which had split just below the flange at the top of the tank. my theory is that when the tank was full, there was too much pressure on the flange which deflected and cracked the tank. I tried to plastic weld it, and it lasted for awhile, but in the end I had to replace the tank.

Just suggestions for anybody else that might want to change a tank........

[firestation12]

Originally Posted by jasin1

What did you find with the old tank? Was it split?

It seems rare that we get the OP's final comments as to what part of their tanks failed. Bike mechanic has been stellar so far at keeping this thread's replies answered. Looking forward to the conclusion analysis. Thanks all...interesting thread!

[wiredgeorge]

Originally Posted by chuckster57

Feel free to come by the shop…your hired!!!

Glad you got it all fixed.

If I were an RV tech, I would strongly consider subbing out black tank jobs!

[German Shepherd Guy]

bikemechanic53
So, what was the failure? Did it actually split or was it something else?
Very Curious.
By the way congratulations on a great job done and finished!!

[bikemechanic53]

Yes. The black tank was split at the connection between the top and the belly. Apparently it blew out before the pressure could push the water out the top of the vent pipe on the roof.

4 Pictures below ( I think I did this correctly.)

First is a picture of the 2 waste tanks in the front of the 387.
Second is a closer pict of the ruptured black tank. Can't see any problems.
Third and fourth are picts of the ruptured tank after I got it out. Blowout is clearly visible. The other hole is from cutting out the toilet drain pipe to get the tank out of the RV.

BOY, This was SO MUCH FUN I feel like I could do it again! ( said no one ever)

[firestation12]

Thanks for the final analysis! I've posted on previous threads, the consequences of over filling the black tank with the dump valve closed. The internal lifting pressures pushing against the top and bottom halves of the tank, will cause a tank of this type of construction, to fail, long before the liquid will rise high enough to exit the roof vent. The total force (in lbs), trying to separate the 2 halves is equal to the total of: 5 psi x L" X W". 5 psi is the required pressure required to push the tank's liquid to the top of the roof vent, which if it should occur, would limit the any further increase of lifting pressure beyond the calculation. Example, if bike mechanic's tank had a top dimension of 20" X 40", the lifting pressure could be as high as 4,000 lbs. I have my doubts that even a blow molded tank could survive without some form of damage. For sure, It would look more like a balloon than a rectangular shape, maybe causing the supporting belly bands underneath the tank, to snap. A a partially filled plastic gas can with no vent, takes on the same shape if left in the sun for a few hours. I vote for 10 extra punches on Bike Mechanic's man card, for taking on this project himself! Well done!