Jump to content

What is the weight of water?


Bob52

Recommended Posts

My Truck Camper water tank is a 40 gallon and wondering what weight would this tank be? I also have a black and gray water tanks which is 30 gallons each, My camper weighes 2700 pounds dry.

2005 Host Bachelor SS Truck Camper, ultralite Aluminum Frame, Double pane windows, One Piece TPO Roof, 40 gallon fresh water, 40 gallon grey water, 30 gallons of gray water, Roof ladder, 34,000 BTU furance, 6 gallon DSI Gas Water heater, Built-in interior Entry step, Dinette Slide-out, Electric Jacks with remote, attic fan, Winterization system, all season,

Link to comment
Share on other sites

At 8.35 pounds per gallon my 40 gallon water tank would be 334 pounds. Then a dually would make a good truck to haul my camper with the water and other stuff I need to haul like plastic boxes that weigh 50 pounds or more each. I have five of them.

2005 Host Bachelor SS Truck Camper, ultralite Aluminum Frame, Double pane windows, One Piece TPO Roof, 40 gallon fresh water, 40 gallon grey water, 30 gallons of gray water, Roof ladder, 34,000 BTU furance, 6 gallon DSI Gas Water heater, Built-in interior Entry step, Dinette Slide-out, Electric Jacks with remote, attic fan, Winterization system, all season,

Link to comment
Share on other sites

You need to be a little more specific.

Are you asking what the weight of 40 gallons of water?

Or are you asking what the weight of your 40 gallon water tank is?

 

It will render a different answer.

2016 Volvo VNL780 D13 I-Shift

2016 DRV 44 Houston

2015 Smart Cabriolet

Link to comment
Share on other sites

Water only. My water tank is plastic which shouldn't weigh much.

2005 Host Bachelor SS Truck Camper, ultralite Aluminum Frame, Double pane windows, One Piece TPO Roof, 40 gallon fresh water, 40 gallon grey water, 30 gallons of gray water, Roof ladder, 34,000 BTU furance, 6 gallon DSI Gas Water heater, Built-in interior Entry step, Dinette Slide-out, Electric Jacks with remote, attic fan, Winterization system, all season,

Link to comment
Share on other sites

For estimating purposes, the old saying "A pint's a pound, the world around" is close enough and easy to remember.

 

This is another reason we should be on the metric system like the rest of the world. One liter of water weighs one kilogram. Nothing easier to remember than that.

2000 Volvo 770, 500HP/1650FP Cummins N14 and 10 Speed Autoshift 3.58 Rear 202" WB, 2002 Teton Aspen Royal 43 Foot, Burgman 650 Scooter

Link to comment
Share on other sites

Water only. My water tank is plastic which shouldn't weigh much.

 

A typical 100 gal plastic fresh water tank weighs ~75 lbs. That's not "nothing"

 

http://www.plastic-mart.com/product/11012/trionic-100gallon-rv-water-tank

Sandie & Joel

2000 40' Beaver Patriot Thunder Princeton--425 HP/1550 ft-lbs CAT C-12
2014 Honda CR-V AWD EX-L with ReadyBrute tow bar/brake system
WiFiRanger Ambassador
Follow our adventures on Facebook at Weiss Travels

Link to comment
Share on other sites

My water tank is a 40 gallon and black tank is 30 gallons and gray tank is 30 gallon tank. That's why the past owner had all the tanks empty when he had the camper on the truck.

2005 Host Bachelor SS Truck Camper, ultralite Aluminum Frame, Double pane windows, One Piece TPO Roof, 40 gallon fresh water, 40 gallon grey water, 30 gallons of gray water, Roof ladder, 34,000 BTU furance, 6 gallon DSI Gas Water heater, Built-in interior Entry step, Dinette Slide-out, Electric Jacks with remote, attic fan, Winterization system, all season,

Link to comment
Share on other sites

Dry weight includes the weight of the empty tanks guys.

RV/Derek
http://www.rvroadie.com Email on the bottom of my website page.
Retired AF 1971-1998


When you see a worthy man, endeavor to emulate him. When you see an unworthy man, look inside yourself. - Confucius

 

“Those who can make you believe absurdities, can make you commit atrocities.” ... Voltaire

Link to comment
Share on other sites

 

That's why the past owner had all the tanks empty when he had the camper on the truck.

Which can work if you always stay in RV parks with full hookups. It is really no problem to always empty the gray water tank before travel but the black tank should be at least 1/3 to 1/2 full before you empty it in order to get the rush of fluid that will carry out anything not yet liquid. You can put water into the black tank in order to get it to that level, if needed. While traveling with less than a full fresh water tank is rather common, as there is really no need to buy fuel to haul water that you don't need, most of us do keep enough water in that tank to have an emergency supply if we should need it or even to spend a night in an emergency. With your tank, I would probably keep about 10 - 15 gallons in the tank while traveling and probably not empty the black tank more than every third or fourth day.

 

If the 2700# that you are using is either a factory spec. weight or one from a scale, that should include all things except those which you will be adding to the RV such as food, water, clothing and personal items. It would be a good idea to get an actual weight to use at a truck scale because then you would be able to consider the GVWR of your truck against your starting weight in loading the RV. Once prepared for travel you then need to weigh it again. Also, pay attention to weight distribution as you load your things into it.

Good travelin !...............Kirk

Full-time 11+ years...... Now seasonal travelers.
Kirk & Pam's Great RV Adventure

            images?q=tbn:ANd9GcQqFswi_bvvojaMvanTWAI

 

Link to comment
Share on other sites

For estimating purposes, the old saying "A pint's a pound, the world around" is close enough and easy to remember.

 

This is another reason we should be on the metric system like the rest of the world. One liter of water weighs one kilogram. Nothing easier to remember than that.

 

 

"A pint's a pound.....etc."

 

Hmmmmmm..... is - "Black and White makes a light and green is ground the world around" - close enough?.. ;)

 

.

Link to comment
Share on other sites

Sir Kirk has covered most of this in his post and he his dead on for real world advice.

To simply answer your question the wt. of water is 8.34 lbs. / gallon

 

40 gal X 8.34 = 333.6 or 334 lbs. rounded

30 gal X 8.34 = 250.2 or 250 lbs. rounded X 2 =500 lbs.

 

total wt. of full tanks is 834 lbs.

 

You will need to work the weight out so that with all your stuff and any water that you need to carry is not an overload on your truck .

Setting in the campground does not count only when you pull out onto the road will you need to worry about weight.

Also don't forget you can manipulate the axle weight somewhat by moving things forward or backward within the camper so that more or less weight is on the front or rear axle .

 

Now a suggestion load your camper the way you would like to travel . Dive to a truck scale ( most good truck stops will have one )and weigh the front and rear. Then you will be able to play around with how much water and where things are at in the camper

Link to comment
Share on other sites

Just as an aside. One common mistake often made is to empty your black before you leave camp. If you know you are going to somewhere with a dump point then let the black stuff slosh around while you are on the road. Dump it as soon as you arrive. Solves many problems for folks who find they are having 'back up' problems.

 

regards

Link to comment
Share on other sites

Depending on the quality of the RV, some waste tanks are so poorly secured that the worst thing you can do is go down the road with product sloshing around inside them. Twenty gallons of liquid sloshing around puts a lot of stress on a plastic tank.

Everybody wanna hear the truth, but everybody tell a lie.  Everybody wanna go to Heaven, but nobody want to die.  Albert King

 

Link to comment
Share on other sites

We ended up with full holding and fresh tanks a couple times, not something we really wanted to do from a weight standpoint. We weren't so worried about the RV weight though, more that the holding tanks are fairly flimsy construction and the supports aren't so great either.

 

Anyway, the reason was that we could fill up with good water where we were camped but they had no dump. The dump we were going to use was along our route and either had iffy water or no water and there was no water available at our destination.

 

Our preferred travel mode was full fresh and empty holding tanks so we could stop anywhere and boondock for a couple weeks but we planned the rig to be safe with a full load.

First rule of computer consulting:

Sell a customer a Linux computer and you'll eat for a day.

Sell a customer a Windows computer and you'll eat for a lifetime.

Link to comment
Share on other sites

I always use the mnemonic phrase "a pint's a pound the world around" to remember how much water weighs, but then I'm a retired school marm. That has a double meaning, by the way. Think beer in a British pub. Yes, it's approximate regarding the weight of water, but it's easy to remember.

Link to comment
Share on other sites

  • 2 weeks later...

I have always use 8.33 lb/ gallon. But if you want more accuracy, you can use:

8.328676 lb/gal at 70 degF.

Ken

Amateur radio operator, 2023 Cougar 22MLS, 2022 F150 Lariat 4x4 Off Road, Sport trim <br />Travel with 1 miniature schnauzer, 1 standard schnauzer and one African Gray parrot

Link to comment
Share on other sites

hot water weighs less than cold.

 

No. The weight of a given mass of water is the same no matter what the temperature is. Weight = mass x gravity.

 

You are talking about density and hydrogen bonding and you will find that the density is the greatest at 4C for liquid water. Obviously density is even less when water becomes a solid - which is why ice floats. A

 

And yes, the 'weight' of water differs when one is looking at altitude because weight is a measure of the pull of gravity on a given mass.

 

Barb

Barb & Dave O'Keeffe
2002 Alpine 36 MDDS (Figment II), 2018 Ford C-Max HYBRID
Blog: http://www.barbanddave.net
SPK# 90761 FMCA #F337834

Link to comment
Share on other sites

Here is a link of a chart showing water density by temp.

 

http://www.engineeringtoolbox.com/water-density-specific-weight-d_595.html

 

As seen on the chart, cold water at 40 degrees F weighs 8.3451 lbs/gal. For 180 degree water (say the 6-10 gallons in your water heater) it will only weigh 8.0969 lbs/gallon. This means that 10 gallon water heater filled with very hot water will weigh about a pound less than with very cold water.

 

Chip

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

RVers Online University

mywaggle.com

campgroundviews.com

RV Destinations

Find out more or sign up for Escapees RV'ers Bootcamp.

Advertise your product or service here.

RVTravel.com Logo



×
×
  • Create New...