In this article, I will discuss how I added an access hole in my black water tank for cleaning.
First, however, I recommend everyone read the safety article.
https://mybounder.com/2022/02/09/safety-first/
I also want to let everyone know that I’m not responsible for anything you do. If you choose to do something like I have and it wrecks your tank, it is not my fault. This article is for entertainment purposes only, do not try this yourself.
I am the 3rd owner of a 1999 36S Triton V10 Bounder. I bought it in April 2020.
The toilet smells were too much, so after reading many online articles I did first thing any smart man would do… listen to his wife! She wanted a new porcelain toilet and I figured it would probably seal better. But, the smells didn’t go away. I tried the various tips and chemical treatments described in the online articles. Then, I got products and advice from the local RV store. Nothing would make it really go away.
There is a possibility that I have a blocked vent tube. A future project will be to test the vent tube and add an evacuation fan in the vent tube. But, there was also another problem with my smelly black water tank which took my attention away from the vent tube. It wasn’t responding correctly to the level monitor on the dashboard. All the LED’s would light up, which happens when too much crud attaches to the side walls of the tank. A sure sign that you need to clean the tank, as if your nose wasn’t enough of a clue.
Having a look around, I found that I could access the tank from the rear right storage compartment. Removing some screws to the cover plate, the tank became very accessible.
I used a special tool to make a custom size (~4″) round hole in the side of the tank. A test hole was first made on a thin piece of wood to ensure the size was correct. Next, with the RV hooked up to my septic tank (through a clear “view” section), the Black water valve was opened (and kept open) to empty and drain the tank the tank during the procedure.
Making a hole in the Black Water holding tank?
My thoughts and concerns were: Do I want to make a hole in this? Really? Will the hole be clean (smooth and round)? Will the plastic crack? Will the plug I bought seal the hole and not crack the tank? So, I took a deep breath and made the hole into the Black Water Tank! The hole was placed a couple of feet in from the left edge and approximately in the middle of the surface shown. Once the hole was put in place, a rag was used to guard the hole and put in the nozzle of my power washer. I then sprayed the walls and swept the floor of the tank with the power wash. First fast, then slower for a deeper clean. A spotter at the drain told me when it was looking clean. I sprayed in every angle I could. In the future, I plan to buy an angled nozzle for the power washer to spray even more spots. Now with the dirty work done, it was time to install the plug.
Buying the right Plug
Several weeks before this job, I bought what looked to be a nice plug. It was bought on Amazon, so I couldn’t really see what I was buying. It turned out that there was too much space between the expanding rubber and the flange of the plug. Amazon took it back without question and I bought another, the Oatey 33403. This plug seals the hole between the flange and rubber when the nut is tightened.
Preparing the hole
Before installing the plug, the hole was made smooth and all debris and filings of the plastic was removed by carefully sanding the rim of the hole with fine sandpaper.
Testing
After the plug had been installed, the black water valve was closed and the tank was completely filled to test and check for any leaks and check the LED monitor. I was pleased to see that there were no leaks and the LED monitor is now working great! But the most important test… did it cure the smell??? Yes! Yes it did!
Final Outcome
No more smell! I’m certain the smell will come back in time after normal use, but now I have a successful way of fixing that!
Future Projects
A future project is in the works to add a water detector to the surface outside this plug, while I’m at it, I should add another sensor under the dump port. Also, as mentioned previously, a small in line fan with the vent tube will go a long way to draw the odour away from the little room, however, I promise nothing to the birds that may be nesting on the roof.
Pictures & Illustrations
Correct Plug – Oatey 33403
Suggested to add a clear section to view the “output”
Camco Mfg Camco 39573 Clear Sewer Hose Adapter 5″
Another worth while addition is this clear plug with smaller drain hole. Let’s you see what’s waiting for you!
Valterra T1020-1CLR Waste Valve Cap – 3″ with Capped 3/4″ GHT, Clear
2 comments
This is great! I would suggest you add this to your must-haves as well: https://www.amazon.com/Camco-Flexible-Powerful-Dislodges-40074/dp/B0006IX7YC
This is a great idea and I was afraid I was going to have to do something similar when I purchased my 2003 35R. One of the first things that the previous owner said to me was that she always kept the black tank drain valve opened since she had it hooked up to the sewer drain on her property. This caused the sensor on the dash to continually say that the tank was full even though I knew it was empty. All I could think of was the giant poop pyramid directly underneath the toilet. As it turns out using the onboard tank flusher and the one that Jon suggests I was able to clean out the tank and the sensor works great now.