Build a level.

[Pat]

A lot of projects, especially larger projects, require more than a small spirit level. Nowdays a lot of folks have abandoned the transit for a LASER level (Muy precio, amigo!) Transits weren't cheap either and a lot of things can go wrong, many in the instrument calibration and or user adjustment department.

Water levels have been discussed here but maybe some folks could profit from a description of how to build one, cheaply, but first some motivation.

Why build an old fashioned thing like a water level when your project needs close tollerances, ease of use, and an econo price. Real affordable LASERS are poor over much distance and can be useless in bright sunlight. Water levels can be read to about a tenth of an inch or so with excellent repeatability. They work fine in bright sunlight. They will work over a range of hundreds of feet or more (if you have enough common garden hose to span the distance.) Not expensive to build or use. No batteries needed (except for your flashlight if you work at night.) Not expensive to calibrate if dropped or abused (do it yourself in a couple minutes for free.)

Parts list:
1 each male and female garden hose ends (repair type)

About three feet or so of clear plastic tubing to fit the garden hose ends (I prefer 1/2 inch fittings and 1/2 inch ID clear plastic hose.)

Some electrical or other vinyl tape or similar.

A grade stake, scrap rebar, T-post, whatever to hold one end of the hose for you, later.

You need common garden hose as long or longer than the greatest range over which you need to compare elevations. If you use multiple hoses screwed together for greater length it sure helps that the connections don't leak. Not a real tough requirement since the pressure is never more than a few PSI.

Not absolutely mandatory but convenient to have is an inline ball valve with male hose threads on one end and female on the other. Also convenient is a yard stick, a few rubber bands, and a 1x2 (or 2x2 or...) 4 to 8 ft long or as required, you decide the length after I mention its use. A small funnel that will fit into the clear plastic hose is handy. Some folks like to have a small spirit level handy to tell when they are holding the 1x2 or whatever vertical. Some tie wraps would be handy but more tape is fine.

Construction:

Cut the clear hose into two pieces, one about a foot long and the other about 2 feet. Connect the female hose end to the 1 ft clear plastic hose. Connect the male hose end to the 2 ft piece of clear plastic hose.

Screw the male end of the ball valve into the female hose end that you put plastic hose on. Wrap some electrical tape around the 1 ft plastic hose midway along its length. Be neat and get it even as this is the index mark where you will read the level indication.

That is about all the construction.

Assembly and prep for use:

You have to fill the garden hose with water. This is most easily done by hooking the female end of your hose to a spigot (faucet) and the other end to the female ind of the ball valve. Open the ball valve and turn on the water. When all the air bubbles are purged, hold the end with the water squirting out above the elevation of the faucet and turn the faucet off. Close the ball valve. Disconnect the hose from the faucet and place the fitting with the 2 ft clear hose on that end trying to not spill a lot of water. It is handy to hold both ends of the garden hose side by side in the same hand so neither is lower and water doesn't try to run out. Add water to the 2 ft clear hose to nearly fill it (overflowing is OK too.)

Drive a T-post, rebar, stake, or whatever into the ground and affix the hose and 2 ft plastic hose to it with ruber bands or tie wraps or... Hold the 1 ft clear hose next to and at the same height as the 2 ft clear hose. Open the ball valve and while holding the 1 ft clear hose vertical, slightly lower the clear hose with the ball valve in it untill water runs out and the height of the water in the 2 ft clear hose falls to within an inch or so of the lowest visible portion of the 2 ft hose then raise the end with the ball valve until the water level is even with the top of the electrical tape and make a pencil mark next to the water level in the 2 ft clear hose.

The only critical part of the above procedure is having the water levels right at the electrical tape while marking the height of the water at the other end.

Now until a lot of evaporation takes place or you spill some water the unit is ready for use. You can try to select a loacation for the stake/post holding the 2 ft clear hose that is convenient to many of your other height (grade) measurements.

An example of a common use is in the next post.

[img]/forums/images/icons/smile.gif[/img] Pat [img]/forums/images/icons/smile.gif[/img]

[Pat]

A sample appication for a water level:

All the other uses are quite similar.

Suppose we are building a retaining wall and need to dig a trench to accept gravel to bed the first course of blocks and we want it to be level. First decide where you want "grade to be in one spot. I selected 66 inches below the nearby porch slab. That was about 52 inches from slab top to dirt plus 8 inches to bury first course plus 6 inches for gravel bed.

I hold the moveable end of the instrument (water level) such that the water is just at the top of the black tape and attach the moving end to a 1x2 with bubber bands so there is 66 inches of 1x2 below the slab top. Some people would adjust the fixed end of the instrument such that the water level was right at the slab top during calibration phase to simplify everything but all is relative and it doesn't matter if you don't mind the math.

Assuming we used the slab top as a reference height then I need the stick to extend below the black tape a distance of 66 inches. At first you will see as soon as you =start to open the ball valve that the end in your hand is too high as the water starts to drop out of sight (and comes up in the other end). Just lower it to prevent that.

You can hold the 1x2 vertical in one hand where you want a reading and have the movable end of your instrument in the other hand. I often just put my thumb over the end of the clear hose at the movable end instead of opening and closing the ball valve so much. (Just for convenience and I don't have three hands.) If the water rises too much when you take your thumb off then raise that end till the water is at the mark. Note the height of the water on your 1x2. Lets say for example it is 51 inches.

This means that the current grade is 51 inches below the slab and we want 66 so we have to dig out 15 inches of dirt. Later after we think we are about done we can walk along the trench and every few feet put the stick down to the bottom and use the instrument to see if we are high or low and by how much.

We can add our gravel and rake it smooth and check it for level with the instrument. As we add courses of retaining wall block we can check the tops of the courses or every 2nd course or whatever with the level to make sure we aren't getting off.

Another application: You want to have 1 inch in 10 ft fall on an outdoor slab. The slab is 15 ft long in the uphill/downhill direction so we need a 1 1/2 inches of total fall. Once we pick a height for either end of the slab and set our water level to it we can go to the other end and mark it 1 1/2 inches higher or lower depending on the situation.

Third application. Marking under eaves for gutter installation. You can walk along under the eaves (assuming no more than a 2 story house for most of us) with your instrument and mark a series of "level" marks using a long stick to reach up to the eaves. Later you can measure from these points to the spots under the eaves where you want to hang the gutters. Masking tape stuck to the house is good to take the marks.

The "water level" refered to as the instrument can be read easily to within 0.1 inches. To check calibration just take the movable end to the fixed end and see if the two water levels are both at their respective marks at the same time they are equal to each other. You can add a drop or two to do a fine adjustment or drip out a drop or two if needed.

The water levels will oscillate a bit after the instrument is disturbed so just wait a few seconds for the motion to stop and the instrument will be dead on as close as you can read it. With practice you can dampen the oscillations by placing and removing your thumb on the end of the tube. Place your thumb on the tube when the water is passing the mark and take it off briefly when it is at the highest or lowest points in its swing. If you don't have better rythm and coordination than Steve Martin's character in "The Jerk" maybe you should just wait a few seconds for it to dampen out on its own. I have seen people using a magnifying glass to read it but I think that is a stretch. Some people put food coloring in the water to make it easier to see but I do fine without.

With practice you can tell where the water height will end up by watching its damped oscillations and make corrections without waiting for the water to stop. I believe, in principle, you could use an extremely long hose but when disturbed it would take a while to dampen out.

In theory you are not defining a level plane but are defining a spherical surface equidistant from the center of the earth or at least normal to the local gravitational field. You aren't likely to notice the difference unless you were making measurements with a few miles of hose stretched out.

The actual doing is much much simpler than trying to describe how to do it. Give it a try, it works well and is cheap and the most costly component (garden hose(s) will have other uses.

The 1 ft clear hose with the ball valve is handy for filling tanks in RV's sprayers and such.

Enjoy,

Pat [img]/forums/images/icons/smile.gif[/img]

[Bird]

Pat, all the folks I've seen the last few years who set up and level mobile homes use a water level, but nearly as elaborate as yours; just a long piece of clear plastic tubing or hose with a jug of water set on a pedestal of some sort (upside down bucket, concrete block, or something similar).

[Pat]

Bird, Yeah, I'm sure it works good enough, for them. They are more interested in getting things alike than set to a specific height/depth.

It is like having a ballance for weighing things. You can tell when things are the same but still not know how much of something you have unless you have standard weights calibrated to he degree of presicion you need.

Same story on the water level. Since I was proposing the water level to replace a high dollar rotating LASER level there is a tad more to the setup so you not only know when two places are of equal elevation you also know by how much elevations vary.

I'm sure a variation using their setup and a yardstick would do as good as what I propose but why buy a couple hundred feet of hose that you may never use for anything else when you can use hose fittings and standard garden hoses you can use again for other things?

The trailer folks use their level over and over and it is lighter and easier to use than a garden hose. Different goals and assumptions, different tools.

Pat [img]/forums/images/icons/smile.gif[/img]

[egon]

I have leveled some roads out at the farm by looking over a small clear glass container filled with hydrating fluid.

Egon

[Al_Wa]

Bird, the clear plastic hose for the entire length assures that if you have air in the line you can see it. Pat's approach does not. Clear vinyl hose is cheep and well worth it for a water level.

[Pat]

Egon, What "proof" was the hydrating fluid and how much of it did you have to drink to make the roads look level?

Pat [img]/forums/images/icons/smile.gif[/img]

[egon]

It was a very hot day Pat. The hydrating fluid container had horizontal rings on it. The road in question was almost at the bottom of a hill and at 90 drgrees to the fall line. I was able to stand at a lower elevation and look through the container using the horizontal rings as reference. Water may have also worked but having a greater meniscus may have missled my myopic old eyes.

It did work as later confirmed by my hand level which had been forgotten on that day.

Egon

[Pat]

Egon, There are some tricks you can do with water or other liquid, using the surface for a mirror that is essentially perfectly level in two axes. Knowing that and some trig and geometry you can sight across the surface of the liquid (using it as a mirror) and do some ratio and proportion stuff.

Celestial navigation with a sextant typically requires a clear view of the horizon at sea. On land there is no practical way to compensate for the unknown elevations of the "apparent" horizon so celestial navigators on land used to use a bowl of mercury to provide a reference to level. Its surface was flat and level and made a good reflector that would let you see the image of a navigatiional star reflected in it. As the sun is so bright, noon shots of the sun can be made with a bowl of water, provided the wind isn't too strong which makes ripples in the water.

I have done some desert navigation this way (pre GPS)

Pat [img]/forums/images/icons/smile.gif[/img]