Sunday, April 22, 2012

"It Pulls The Water Up"

I wrote yesterday about our cast iron water pump. A lot of people asked for more information, so right at the top of this post I'm going to say that you can get a new one very much like the one we have for around $50 -- no need to scrounge around for a vintage one -- and it will be the best outdoor play investment you'll ever make. With basic maintenance, it will last for decades.

That said, I found ours in the back of a storage closet when I first arrived at Woodland Park 10 years ago, apparently abandoned there by the teacher who came before me. I know the teacher who came before her and I'm quite certain that she used it, although the pump itself may well have pre-dated her. In any event, as an investment, rest assured you'll more than get your money's worth, and that over a long period of time.

Until I discovered it, 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, including those two long protruding bits, 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" (leather valves) 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 too many days without rain, we know to prime the pump by pouring a little water into the cylinder while pumping to get everything re-moistened.

A couple years ago, I decided I should make sure I wasn't the only one who knew how to clean and otherwise maintain the pump, so I began to involve some of the parents in the process, one of whom is a contractor. He suggested we could improve the pump's performance by adding a little plumbing grease, and sure enough that's made the whole thing far less finicky.

We haven't always had a permanently installed pump. In fact, this is only our second full year. For most of my tenure here, we just used the water pump in the muck bucket as an occasional, temporary set up. It's a simple way to get started, one I recommend to those of you who have had this "on my list" for too many years or who don't think they have enough room. Aside from being a down and dirty way to get started, another benefit is that you can experiment with where the kids have their water supply, moving it around for specific projects. The only real downside other than the minor hassle of setting it up each day, is that the kids tend to treat it as something "special" queuing up for a turn, bickering, negotiating, and so on, which is great stuff for sure, but it means only the most persistent kids really get the time to create much of a relationship to the pump, to get to know it with the intimacy required to really understand it. That's the biggest advantage, I think, to having a permanently installed pump: they still bicker and negotiate, but it is no longer the core aspect of their play, clearing more space for the science learning.

For instance, the other day, Finn found the pump handle unoccupied and began pumping very slowly, stopping at the top and bottom of each stroke, a luxury we never had when it was a temporary installation. Most of the kids, most of the time, stay focused on the water itself, watching it emerge from the spout and following whatever course it's taking today, but Finn was watching the mechanics of the pump. When kids ask questions, I explain how a pump works. We even sometimes take it apart to show the kids what it's like inside, but what Finn was doing is a much surer way to learn.

He was losing himself in his thoughts, when a few of the kids performing water experiments of their own down stream began to grow impatient, shouting, "Pump faster!" He didn't respond, however, continuing his slow motion up and down pumping, drawing mere trickles of water with each down stroke.

"Pump faster! Pump faster!"

He was not going to be hurried. Finally he said to no one in particular, "It pulls the water up."

He's not the first kid to have that epiphany. Some of them learn it when I take the thing apart, like I did, and some of them learn it, like Finn, with their eyes and deep thought. Others have learned by watching their friends. Most of them, however, have learned it through the motion of their whole bodies, internalizing it almost like an intuition or a memory. 

When our more recent alumni return to visit us for a day, the pump is usually where they head first. I remind them, "If you play with water, you might get wet," and they reply, "I already know that." That's not all they know.

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Morah D said...

Wow! That looks incredible and like loads of fun!
I love eating about your experiences!

Faigie said...

What an amazing learning experience. These are the types of learning experiences that the children will never ever forget. Its usually these kind of experiences that propel the kids that had them into professions in the sciences where they trace their interest in their chosen fields back to their early childhood experiences