Priming The Pump

In yesterday's post I wrote about monkeying around with our cast-iron water pump.

In a comment, Donna from the terrific blog Irresistible Ideas For Play Based Learning, mentioned that their school was contemplating the acquisition of one of these simple water moving machines, but was concerned about my casual reference to having to regularly take it apart and put it back together. Knowing how to do this, or having someone readily at hand who knows how to do this, is essential to owning one.

I inherited parts of this pump when I took on my current position at Woodland Park. I found it behind a bunch of junk in storage closet, apparently having not been used for several years. I'd never been personally involved with a preschool that had its own water pump, but I'd heard such items discussed among my fellow teachers with great enthusiasm and even reverence. It came already attached to that wooden platform you see in the picture, with its 18-inch intake pipe emerging from the bottom. At the time, we only had one vessel deep enough to accommodate the pipe, a muck bucket like the one pictured below.

It was a perfect fit, telling me that it had been made specifically to fit over such a water supply. I filled the bucket with water, but no matter how hard I pumped, I couldn't get it to draw water. Now, I understood in theory how a pump worked, but my hands-on experience was zilch. The thing wasn't working. Could I really make it worse by taking it apart to see if I could figure out what was wrong?

A quick investigation found that there were only 3 bolts holding the whole thing together, two at the base and one at the top. I started by loosening the one at the top with a wrench and after a few turns the entire lever apparatus came off, attached to the "piston" part. I could see right away what was wrong. I knew that for the piston to create suction, it would need to fit tightly into the cylinder and this one didn't. There was a cup-like fitting (which I was later to learn was made of leather) on the piston that was shriveled and cracked. I could remove it easily by unscrewing the piston from the rod. A little internet research told me that there are, in fact, two "leathers" required to create the seals needed for suction. The second leather was a ring that fit around the base, which I would have discovered if I'd removed the other two bolts.

There are standardized sizes of these leathers and after a little investigation I figured out the size I needed and located an online supplier. Installing the new leathers was a piece of cake. Anyone who can remove and replace a bolt can do it.

Excitedly, I got the newly be-leathered pump ready for its trial run, but again was foiled. It still didn't draw properly and the handle was very, very hard to pump. I left it outside in frustration and went home for the night. Luckily, it rained. The next morning, I tried the handle again. This time it moved easily and after a few pumps began to draw water! The leathers apparently needed to be wet in order to function properly. I've since learned that this is what is meant by the expression "priming the pump." Now, whenever the pump has set idle for a few days without rain, we know to prime the pump by pouring a little water into the cylinder while pumping to get everything re-moistened.

For years, we had fun using our pump as an occasional and temporary installation, usually setting it up near the garden and employing house gutters to create a "raceway" in which the water can flow, but we wanted a permanent water source with our playground redesign, hence all the fiddling around with it over the past month.

If you don't have a pump, I highly recommend one as an addition to your outdoor play area, at least as an occasional, temporary installation. I'll let you know in an other month or so if they're worth the effort on a "permanent" basis.