You Can Build a Real Waterpump

We can built a BILGE PUMP that works…

bilge pump finished

A bilge pump draws water from the lowest level of a ship’s hull, or from any lower level where water can pool, to a higher level. You can also pump water from a pail into a container.

Build your own pump and have a race with your friends to fill a yogurt container with water from a larger pail. Who pumps the fastest wins. BUT to pump fast you need a tactic: move the piston up and down gently but regularly and you might win the contest. Only one can win, but you all have much fun.

Warning: do this outside… it is a watery game!

If you really want to know how this pump works, go to the side bar and click “Understanding WATER PUMPS”.

The materials you need for our water pump

Here are the materials you need.  A coat hanger, a piece of electrical conduit, that is a plastic tube, a few washers, a leather or rubber washer, a short piece of flexible tubing and a cork n and marble, and at last, a short piece of black fuel tube from a garage; they have lots….

Top of the pump assembly.

Drill a small hole at one end of the plastic tube, which is also called the “cylinder” The soft plastic tube should go tightly into this hole. The cork has also a hole drilled in it and this should slide over the coat-hanger wire and act as a stopper while still allowing the wire to slide in and out of the pump. 

The  piston

The piston is the part that moves the water when you  pump. You can see here how it fits together: a bend piece of coat-hanger wire, a small metal washer, a larger metal washer that supports the rubber or leather piece, the piston, and then on top of the piston another metal washer and a piece of flexible tubing to hold it all together and keep it in place when the pump works.

Piston and cylinder assembly

The piston goes into the tube or cylinder. Note we have added a cork with a small hole in it so the coat-hanger wire or piston rod can slide in it but it should be small enough to keep the water back in the cylinder when pumping. The coat-hanger wire should be long enough to stick out of the cylinder so that we can bend it to make a handle.

The foot valve assembly

At the other end of the cylinder we take the marble and the short piece of fuel line tubing and put the marble on top then push it into the tube or cylinder. This is the “foot valve” that allows the water to be sucked up into the cylinder when we pull the piston up, but prevents it from escaping when we push the piston down. 

You finished the pump, congratulations!

And here is your finished pump. You might need to fine-tune it, don’t loose patience, try to find the problem if there is any and solve it. That may need the help of an older person. BUT this is what engineers do all the time, it is called trouble -shooting…

Try the  pump in the sink or in a container the water will come out of the narrow tube at the top of the pump, you pump water from a lower level over a height to discharge it over the rim of the container or if it is used on a boat, you suck the water from the bilge and into a pail or overboard into the river or lake…