I know - it's riveting topic.
The next step for me with my plumbing is to learn about reservoir tanks. After reading a lot of (mostly mind numbingly vague) information online, I decided to I needed to speak with an RV repair specialist. RVs use reservoir tanks, and being a visual person, I needed someone to help me get the overview of what my goal is. Fortunately for me, I had a "power of who" connection and after a brief email exchange I was on the phone with Rodney, an extremely knowledgeable gentleman at an RV repair company in Dallas.
We were on the phone all of about 6 minutes before he threw out the phrase, "tongue weight" -- said he was sure I'd heard about that -- and just barreled onward. Whoa whoa whoa - tongue weight? I have never in my life heard that phrase. Back the truck up.
Apparently "tongue weight" is common parlance in the RV industry. There is a calculation you should do to make sure you position the weight on your trailer correctly. In this case, we were discussion my water reservoir tanks that I plan to mount under my trailer, between the front axle and the trailer tongue. A gallon of fresh water weighs 8.34 pounds. If I plan on having two 20 gallon tanks of water sloshing around under my trailer, that is over 300 pounds.
Then he started speaking about "sway." Apparently if you ignore the tongue weight calculation, or do it incorrectly, and you are not within the high and low percentage of trailer tongue weight, once you hit a certain speed (this is starting to develop the feel of algebra, which I barely passed. Pick me for your spelling bee team...) your trailer will start swaying on the freeway. I'm told this is very difficult to control. Awesome.
I found this article online that explains the calculation. My eyes crossed at about paragraph six.
Here's an excerpt:
Finding the tongue weight (TW) of any trailer can, at first, seem like a difficult task. Fine-tuning the tongue weight to fall within the 9- to 15-percent weight range of the gross trailer weight (GTW) might seem nearly impossible. You'll be happy to know that it doesn't have to be complicated at all.
(I don't know, that seems like a lie.)
In other interesting news, a quick Google search revealed that if I can't find a tongue weight scale to use for free locally, I can buy one* for under $150. They look like this:
Here's the link for that photo:
Rodney also gave me a couple of other advisories:
1) My fresh water tank and my gray water tank should be identically sized. Reason being, if someone leaves the faucet on and goes outside, the gray water tank will be large enough to accept ALL of the water from the fresh water tank. I likely would have figured that out with my keen sense of common sense, but who knows.
2) Buy tanks made from HDPE plastic, not ABS plastic. I neglected to ask why that is because I was furiously taking notes, but I'll ask him next time we speak; it was something about the strength of the plastic, I think.
His company sells reservoir tanks, and I told him I wanted to talk with him more about all of this (hire him if necessary) and that I would order my tanks from him. He said he'd need to see the trailer to know exactly what we are dealing with. I promptly sent him my floor plan and some photos. I'll be back in touch with him in a few weeks...
I don't know why it took me so long to identify an RV repair place (and/or a marine repair place) as a great resource for this topic... but it's going to be a great help to me. Hey, so I'm slow. But I get there eventually...
Daniel also advised me that I want to place my tanks as close to where in the house that I will be using the water as possible. Okay so that's logical. Unfortunately, attaining that goal seems a bit tricky to me, because my kitchen and bath are not at the tongue end of the trailer; they are on the back end. Dilemma. We discussed me putting one tank behind the axles, and one tank in front of the axles. That could be a solution...
So, some additional plumbing progress. Still a bit to go, but I'm chipping away at it... segment at a time.
Boneyard Studios posted a very informative post about plumbing last year - you can read that here.
* At which point I emailed the link to Nina with the advisory that this falls into the category of, "who knew?" and of course, because we are twins separated at birth, she wholeheartedly agreed with me.