Appropriate weight behind rear wheels?

[retiredChemist]

Weight below the floor not above.

[Rameses]

Originally Posted by retiredChemist

Weight below the floor not above.

Oh, okay, I thought you meant a vertical tank inside the bus.

I think I'd be hesitant to mount a deep tank under the floor though. The farther down you go, the greater your chance of catching it on something and/or punching a hole in it.

[DoubleO7]

The added weight of all that water would be an asset with traction.
But if there are no baffles in the tanks, half full tanks could cause a problem during a sudden avoidance maneuver.
At some point the tail might be wagging the dog.

[Rameses]

Originally Posted by DoubleO7

The added weight of all that water would be an asset with traction.
But if there are no baffles in the tanks, half full tanks could cause a problem during a sudden avoidance maneuver.
At some point the tail might be wagging the dog.

The shape of the tank also makes a big difference. I used to drive a work truck with a 500 gallon cylindrical water tank on the center of a flatbed. With it only half full, you could never feel any side-to-side slosh because the rounded sides did a good job of redirecting the force of the water. Front-to-back slosh, however... The water hammered against the flat ends of the tank and would create a wicked surging effect while going down the road.

I'd be hesitant to use a box shaped tank for that reason.

[Tango]

That's what proper baffles are for preventing.

[ourmefa]

I will be installing baffles in all of my tanks. It is an additional cost, but I like the idea of doing anything I can to reduce the chance of sloshing. I just wish they were not so darn expensive!

Water Tank Baffle Balls

[oredigger]

Originally Posted by ourmefa

I will be installing baffles in all of my tanks. It is an additional cost, but I like the idea of doing anything I can to reduce the chance of sloshing. I just wish they were not so darn expensive!

Water Tank Baffle Balls

How are those baffles installed? It says 8"-15" openings but the RV tanks I've seen only have 1-1/4" or 1.5" openings.

[cadillackid]

I have a general question that I nevder understand the answer to... I hear a lot of people complain about cleaning black tanks.. how come people dont just have 1 waste tank with all the waste water? this way you have plenty of water when it comes time to empty the poo...

or when emptying tanks, I presume at some kind of RV service point why7 people dont just put a hose into the toilet and fill the black tank up so its easier to drain..

im not uop on RV-etiquette is there something im missing? and why so many people use dry toilets..?

-Christopher

[ourmefa]

Originally Posted by oredigger

How are those baffles installed? It says 8"-15" openings but the RV tanks I've seen only have 1-1/4" or 1.5" openings.

I am planning to have a fill lid installed in the tanks when I order them. They don't charge a lot to do this, and you can get them in different sizes. This can be handy if we ever have a situation where we need to flush or clean the tanks. There will be an access panels inside the bus for getting to the opening via the raised floor we will be installing.

Here is our current layout of the bus, the first photo is with the raised floor shown and the center channel of removable panels.


Click for large view - Uploaded with Skitch

This shows the location of the tanks. I chose to straddle the rear axle with the tanks, thinking this is like the most stable positioning for extra weight.

Over all our build will not be super heavy as I will use less wood and more steel for structural components.


Click for large view - Uploaded with Skitch

I am also thinking about installing these tank rinsers into the waste water tanks. https://www.amazon.com/Camco-40126-T.../dp/B000BUU5TU

[Rameses]

Originally Posted by cadillackid

I have a general question that I nevder understand the answer to... I hear a lot of people complain about cleaning black tanks.. how come people dont just have 1 waste tank with all the waste water? this way you have plenty of water when it comes time to empty the poo...

or when emptying tanks, I presume at some kind of RV service point why7 people dont just put a hose into the toilet and fill the black tank up so its easier to drain..

im not uop on RV-etiquette is there something im missing? and why so many people use dry toilets..?

-Christopher

My understanding is that it used to be acceptable to just empty your grey tank onto the ground. If sewage were mixed with it, you couldn't do that.

[ourmefa]

Originally Posted by cadillackid

I have a general question that I nevder understand the answer to... I hear a lot of people complain about cleaning black tanks.. how come people dont just have 1 waste tank with all the waste water? this way you have plenty of water when it comes time to empty the poo...

or when emptying tanks, I presume at some kind of RV service point why7 people dont just put a hose into the toilet and fill the black tank up so its easier to drain..

im not uop on RV-etiquette is there something im missing? and why so many people use dry toilets..?

-Christopher

Personally, I am going with a composting toilet just to avoid ever having to empty a black tank, not to mention having to unclog one. One stray tampon in the macerator pump and you are up to your elbows in poop. No thank you.

[lucasd]

Originally Posted by cadillackid

how come people dont just have 1 waste tank with all the waste water? this way you have plenty of water when it comes time to empty the poo...

I have no idea about that one. I've seen comments to the effect that some RVs actually do have a combined tank, but I haven't dealt with one like that. Maybe there are some places that allow gray water dumping but not black water?

One issue that comes to mind is that it is possible, in an RV, to forget about the limited waste water holding capacity. If you put too much water down the drain, without dumping waste tanks, then you get a back-flood of gray water coming up out of the lowest drain. As in, you run water down the kitchen sink, and all of a sudden a stinking mess of stale gray water bubbles up in your shower.

If you only had a combined holding tank, then the effect of that kind of malfunction would be even worse. This usually isn't an issue, since it would be pretty goofy to design a system with more holding capacity on the fresh side than the waste side, but if you hook up to a fresh water line at a parking spot and forget to open the drain valve....

Oh, that reminds me of another reason - when you are parked long term somewhere, you often want to constantly drain your gray water for showers, laundry, dishes, cooking, etc., but you can't leave the black water valve open all the time. There simply isn't enough water used in an RV toilet to flush solids all the way through the blackwater system, through the external hookup hose, and down the sewer pipe. If you try, the little water that does go into the black tank will drain, leaving behind an increasing mass of solid waste that gobs up your sewage system.

I presume at some kind of RV service point why7 people dont just put a hose into the toilet and fill the black tank up so its easier to drain..

That's exactly what people do. At least, it is what I did when I used one. It seemed to be the only way to even come close to draining the black water tank properly. Some RVs have waste tank cleaning wands mounted near the toilets just for this purpose - to spray water into the sewage tank.

and why so many people use dry toilets..?

A lot of people just don't like sewage? I'm not sure. I've had some really stinky experiences with black water tanks, but that doesn't mean I'm ready to carry poo around in a bag. That really doesn't strike me as an improvement. I do, however, have some design plans to minimize the hassle involved with draining and cleaning the tanks when I get mine built.

As for dry toilets... I will leave the litter boxes to my cats. ;)

[cowlitzcoach]

The grey water didn't use to have tanks. I can remember one travel trailer we had that had a hose fitting on the outside of the trailer so you could put a hose to drain the kitchen sink away from the trailer. What came with the trailer was a hose that was just long enough to reach the ground.

The problem with most black tanks is if you don't have enough liquid the solids won't flush out. Most RV toilets us a fraction of the water a house toilet will use. Most house toilets use 1.5 gallons per flush. Most RV toilets use less than 0.5 gallons per flush. If you have women using the toilet you also end up with a lot of paper product that absorbs the water.

Ideally, when you go to empty the black tank it is best to use water to fill it to the brim before you open the valve. Once it is empty if you fill it up again to flush it out you can usually get all of the solids out.

After the black tank is flushed out if you then flush the grey tank out it will clean out most of the solids from the black tank out of your sewer hose.

What can be a problem is if the tank was filled or partially filled when parked. If the black tank is left with solids in the tank over several weeks the solids tend to turn into solid mountains. It can be exacerbated with sub-freezing temperatures. When you have solids that are petrified it can be a bit of a challenge to clean them out. Rehydrating is the first step. But if filling the tank with water and letting it steep for a day or three doesn't work you will need to invest in a RV black tank product designed to "release" solids.

If it is frozen about all you can do is wait for spring.

[lucasd]

Originally Posted by ourmefa

Personally, I am going with a composting toilet just to avoid ever having to empty a black tank, not to mention having to unclog one. One stray tampon in the macerator pump and you are up to your elbows in poop. No thank you.

It really boggles me that macerators can't grind tampons (I guess it's usually the strings that do them in?) or even wet wipes sometimes. I expect to use one, but I'm thinking about putting it between the toilet and the black water tank. At least if it dies there, I won't have an entire tank trying to drain when I replace it.

[mbnomad]

Hello All,

Been lurking around here for a bit, doing a lot of reading and resurch about this skoolie consept as life has taken a turn in a different direction, but that's another story.

Anyway, I have read a lot of posts from folks that are asking about what basically comes down to wieght distribution acroos the frame of the buss, (i.e. the placement of water/waste tanks and other heavy "main frame" items, but in all the responses, I have yet to read where anyone talks about the the OEM design specifications for the oveall chassis/ frame system. I believe that the "sweet spot" wieght distribution between front and rear axels should be around 60/40 meaning that in a "normal" operting capacity, 60% of the GVWR would be on the front axel and 40% on the rear axel. much like a towed trailer should be loaded.

Is my thoughtnprocess wrong?

[Brad_SwiftFur]

Originally Posted by mbnomad

Hello All,

Been lurking around here for a bit, doing a lot of reading and resurch about this skoolie consept as life has taken a turn in a different direction, but that's another story.

Anyway, I have read a lot of posts from folks that are asking about what basically comes down to wieght distribution acroos the frame of the buss, (i.e. the placement of water/waste tanks and other heavy "main frame" items, but in all the responses, I have yet to read where anyone talks about the the OEM design specifications for the oveall chassis/ frame system. I believe that the "sweet spot" wieght distribution between front and rear axels should be around 60/40 meaning that in a "normal" operting capacity, 60% of the GVWR would be on the front axel and 40% on the rear axel. much like a towed trailer should be loaded.

Is my thoughtnprocess wrong?

Yes, there is a *REASON* the front axle has a lower rating than the rear axle, and to that end, the rear (usually) has dual tires. Try reversing your percentages to something more 40/60, front/rear, respectively.

[mbnomad]

Yes, I did get my numbers backwards, but hey it was dark and I was drunk, hahaha

[TheHubbardBus]

Our plan (not yet implemented) is two identical freshwater tanks on either side of the bus directly behind the rear wheel wells, on the floor of the interior of the bus, linked by a common drain/output pipe. Our single greywater tank, the same capacity as one of the freshwater tanks, will be centered below the floor between the frame rails. So our water will be split for less sloshing, and the side-to-side weight distribution will always be balanced. As for tank dimensions, in order once again to keep it as close to the wheel-wells as possible, we opted for tanks wider than they were long, rather than the other way around

Our other 'big weight' - our house battery bank - was placed as far forward as possible. In our case, just forward of & to the right of the drivers seat (which also centers it side to side).

Intuitively, I feel this approach with our specific bus and components will work out fine, but I haven't 'done the math'. We've got a lot of spring in the back. As long as we don't go overboard I'm inclined to believe the water in the back will enhance handling rather than the other way around. But if not... that can be changed.

[Sleddgracer]

Originally Posted by TheHubbardBus

Our plan (not yet implemented) is two identical freshwater tanks on either side of the bus directly behind the rear wheel wells, on the floor of the interior of the bus, linked by a common drain/output pipe. Our single greywater tank, the same capacity as one of the freshwater tanks, will be centered below the floor between the frame rails. So our water will be split for less sloshing, and the side-to-side weight distribution will always be balanced. As for tank dimensions, in order once again to keep it as close to the wheel-wells as possible, we opted for tanks wider than they were long, rather than the other way around

Our other 'big weight' - our house battery bank - was placed as far forward as possible. In our case, just forward of & to the right of the drivers seat (which also centers it side to side).

Intuitively, I feel this approach with our specific bus and components will work out fine, but I haven't 'done the math'. We've got a lot of spring in the back. As long as we don't go overboard I'm inclined to believe the water in the back will enhance handling rather than the other way around. But if not... that can be changed.

keep in mind that on icy roads, the longer your vehicle is, the more it wants to go straight ahead in the corners - an easy tell to know when you have the balance between front and rear wheels is when your front springs start lifting the front of the bus higher than where it sits normally - too much weight in the back of your vehicle and it wants to switch ends on an icy highway

[TheHubbardBus]

Originally Posted by Sleddgracer

keep in mind that on icy roads, the longer your vehicle is, the more it wants to go straight ahead in the corners - an easy tell to know when you have the balance between front and rear wheels is when your front springs start lifting the front of the bus higher than where it sits normally - too much weight in the back of your vehicle and it wants to switch ends on an icy highway

Thanks for this, Sledd! Very good to know. At least with water, it's always possible - if not necessarily practical - to adjust the load. Still going to baffle tanks as well if possible.