Rust in black water tank.

[Stump Jumper]

When dumping my black water tank on several occasions, I have noticed a sound almost like gravel rolling through the sewer hose. Upon investigation, I found rusted flat metal pieces in the hose. The pieces are as large as 1" in diameter, but most are smaller. I cannot imagine where they are coming from. Any ideas?

[Cypressloser]

I could think of kids/grand kids .....

[Stump Jumper]

Our kids are 24 & 20 and there are no grandkids yet, so hopefully no issues there . I am just worried that there is some structural issue, but I cannot imagine what metal would be located inside the black water tank...

[Bigd9]

Assuming the tanks are a plastic type of material and don't rust, the only thought that comes to mind is something was left inside the tank during construction and it is just now rusting to pieces??? Maybe a saw blade? Just a WAG.

[4x4van]

Not sure, but could they be parts of the tank sensors?

[Old-Biscuit]

Originally Posted by 4x4van

Not sure, but could they be parts of the tank sensors?

KIB sensors......
Left side non-installed
Middle...installed (grommet compressed---bolt threads exposed for wire connection)
Right side...individual parts




This is a 'spin weld' probe....high speed drill installs/welds probe in place.



Parts are stainless steel...but of unknown quality.
Large 'head' of bolt is what is inside tank

Other than that..no metal parts in waste tank system.....ABS drain lines, ABS dump lines, Plastic waste tanks

Foreign bodies......dropped into toilet OR left behind by installer.
But holes cut into tanks are usually done with large 'hole saw' (time...hole saw faster)

[papa&susu]

when the black knife became inoperable and I had to change.... out came a 25 foot measuring tape!!!! Must have been in there since it was manufactured.

[TonyMac]

Too much iron in your diet?? Knock-outs from electrical junction boxes, when combined with knuckle-dragging, troglodytic assemblers, could also explain this phenomena. I'm going with the diet. jm$.02

[Stump Jumper]

Ha-ha, too much iron in the diet could be right. Judging by the size and shape of the metal pieces, I am guessing it is not the sensors. Thinking that maybe something got dropped in the tank by the previous owners or that something was left in the tank by the installers. Thanks for all of the feedback. Just wanted to make sure that the tank was going to detach from the frame while I am driving down the highway. That would be bad for everyone

[sikoriko]

Left over items from the factory. I removed my black and gray drain valves to clean them out,( leaking through), and found a bunch of excessive glue and metal debris. I guess the neanderthals who worked on these rigs can't reach a trash can to throw their stuff away the right way.

[Bigd9]

Originally Posted by papa&susu

when the black knife became inoperable and I had to change.... out came a 25 foot measuring tape!!!! Must have been in there since it was manufactured.

All RIGHT! A little cleaning and you have a great measuring tape.

When we bought our new to us coach the black tank valve was leaking. Being a tightwad, I removed the knife valve assembly and performed a sewer autopsy. Stuck between the valve's sliding knife and rubber seal was a hearing aid battery causing the leak. Sad to say, the battery voltage was a big fat 0 volts.

[Bigd9]

Now don't be calling Bubba names . Poor Bubba, when they first hired him the boss said "Bubba clean this coach up and throw away all the debris that is on the floor". Now Bubba isn't the sharpest tack in the box, so he did exactly as he was told. He cleaned the floor, and saw the hole where the toilet was supposed to be mounted soon, and swept everything in the hole. The floor was all clean and the trash was disposed just like the boss said.

Actually, this story isn't that far from the truth. When our home was being constructed, the owner of the contracting firm showed up one day and told the workers to clean up the shell of the house including the garage and throw everything in the trash dumpster. They did exactly as instructed. That evening when I went dumpster diving (I had an agreement that anything I found in the dumpster I could have). I found an almost new electric skill saw, a broom, several rolls of electrical wiring, electrical boxes and all of the plumbing fixtures for the entire house still in the original boxes!!!! Next day I called the contractor and asked him how much he would pay me for all of stuff I found in the dumpster!

[olcarguy]

Originally Posted by Bigd9

Next day I called the contractor and asked him how much he would pay me for all of stuff I found in the dumpster!

Well did he buy it back or did you sell it to someone else? Gotta know

[Chargerman]

The rust looking pieces is actually dried remnants in the tank from the lack of thorough cleaning during dumping. This can happen when using macerators or leaving the black tank valve open at campsites. A few real good full tank dumps along with rinsing should get these deposits cleared out.

Good luck