New PROPANE TANK 4 Water Storage ???? - Welding progect

[JimRB]

My math agrees with FordMan and OldMcDonald. I am working with US gallons which is 7.48 US gallons per cubic foot. A thousand gallon tank is 133.6898 cubic feet. A thousand square foot roof is a thousand square feet whether it is 2/12 OR 12/12. 1 inch of rain is 1/12 or .08333333 of a foot. Or an inch of rain yields 83.333 cubic feet of water also known as 623.333 gallons. 1.6 inches of rain falling on a thousand square feet yields a 1000 gallons. A quarter inch of rain is 155.833 gallons.

 

[JimRB]

Adding 6 feet increases the roof size 192 square feet. Back to .08333333 X 1192sf yields 99.33 cubic feet of water or 743 gallons of water collected with an inch of rain. Or 297 gallons with a quarter inch of rain. You could add some more square feet if your barn has overhangs.

 

[crash325]

For several reasons I will go with the steel tank.
Original steel tank lasted about 18 years. No problem with rust in water.

Was hoping someone had drilled or cut 1 up. Mainly want to know how thick the metal is.

Thanks to all for your replies.
Jim

 

[dfkrug]

Was hoping someone had drilled or cut 1 up. Mainly want to know how thick the metal is.

I have cut a few, but nothing that big. The one I converted to diesel storage had 0.162" walls.

Note that propane tanks can be made in DOT or ASME versions, or at least my 125-gal tank
I bought new was (420#). One is thicker than the other.

 

[drizler]

Not sure I see the reasoning behind using a tank designed for so much pressure for water storage? Go buy a couple of those 300 gallon totes for water storage. Those are easy to use and move around.

If you are looking for a welding project there may be better ways to utilize a propane tank. I"ve been trying to figure out a use for a 1,000 gallon tank as they are only $750 from this place.
Used Propane Tanks - Repurposed Materials

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Dang, they sure are proud of that ton and a half of scrap steel aren't they? Scrap value say 350 ish and essentially useless. Sounds like they are stickin it to somebody one last time after that tanks long lifetime of their crooked pricing and filling tactics. Typical for propane dealers.

 

[drizler]

Not sure I see the reasoning behind using a tank designed for so much pressure for water storage? Go buy a couple of those 300 gallon totes for water storage. Those are easy to use and move around.

If you are looking for a welding project there may be better ways to utilize a propane tank. I"ve been trying to figure out a use for a 1,000 gallon tank as they are only $750 from this place.
Used Propane Tanks - Repurposed Materials

Only 750, **** but they are pretty proud of that useless piece of steel scrap that's not worth more than 400 tops? Typical propane company, gotta stick it to somebody one last time.
Go plastic. That's what they are made for and do the job extremely well. Besides you won't have to play inventor trying to get everything workable.

 

[crash325]

I have cut a few, but nothing that big. The one I converted to diesel storage had 0.162" walls.

Note that propane tanks can be made in DOT or ASME versions, or at least my 125-gal tank
I bought new was (420#). One is thicker than the other.

Thanks for the info & picture. Much appreciated.
Jim

Plastic in this part of the world rots fairly fast, it cannot take the sun.

Very hard to weld plastic.

 

[roadhunter]

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Dang, they sure are proud of that ton and a half of scrap steel aren't they? Scrap value say 350 ish and essentially useless. Sounds like they are stickin it to somebody one last time after that tanks long lifetime of their crooked pricing and filling tactics. Typical for propane dealers.

I guess it just depends how you look at it. Some might see it as a good starting point for a project such as a bbq grill.

Kinda like the OP. There are other ways to store water but he is looking for something a little different.

 

[OldMcDonald]

The math sounds right but it doesn't work in real life. All I know is that when my rain gauge showed "about" 1/4", I could usually count on the tank being full again. Whether it rained at a rate of 1" per hour for 15 minutes or rained all night for a total of 1/4" It didn't seem to matter. . All I care about is what I get in the tank.

The barn I'm collecting rain water from is 32x30 with a 2 in 16 pitch on corrugated steel roof. So do you increase the surface area for corrugated steel? .

It does work in real life. It is the only way that it is possible to calculate how much water can be collected from a given area, and it is essential to get the maths right if it is critical that you collect a minimum amount of water with a given amount of rainfall - as it was for me when I farmed in Australia. Gauges there measured small amounts in 1/100ths of an inch, then tenths after a certain amount. Here I measure to the nearest millimetre. Under the circumstances I had in Australia, where rainfall was the only water, you must know your collecting area and the required storage capacity. I assume it is quite important for the OP to have this information.

If your tank is full after one quarter inch of rain, or even 1", then it was not empty to begin with. It does not matter what the intensity of rainfall was (except there will be a little bounce off the roof area if it is particularly fierce) - it is only the total that matters. I totally agree with you that the only thing that matters is what you get in the tank.

The pitch of the roof does not matter either, but the corrugations do add a little to the surface area (as does your overhang of course) but not sufficient to give 1000 gallons from even an inch of rain. An exaggerated example of showing how the corrugations would add area to the roof is to place a piece of cloth (a handkerchief will do fine) on a flat surface, mark the edges and then pinch the centre of the cloth between a thumb and a forefinger and raise it slightly. Note how much that the area originally covered is decreased. For this reason, undulating land has a lot more surface area than a flat field covering the same area around the boundaries.

JimRB, 743/4 is not 297. Not important in the context of this thread, but it is if your project needs to include the right amount of roof area and storage. You might die of thirst in some places if you get it wrong. I bet the serious preppers make sure they get it right.

 

[Jim Timber]

Surface area of the corrugations don't magically make the roof take up more area as far as the rain is concerned. It probably slightly helps in retaining it as edge bounce is reduced, but the water encountering the roof is still no greater than the shadow cast by the structure itself in relation to the direction the rain hits it.

So if you had a wind blowing the rain at a 20 degree angle as it fell, your roofline would approach the rain at an angle and might collect more than if there was no wind, but not appreciably more. The wind causing more sideways impact would also potentially be blowing some of it off the back where it normally would've collected too, so there's a hit or miss aspect to that as well.

Think of a shower head and a cookie sheet in the bathroom. Your sheet will only block a given amount of water regardless of how you hold it to the source. As you increase the angle, it reduces the area covered no differently than the pitch of your roof increases the length of material needed to cover it as it goes up. The foundation size doesn't change.