Science With Secondo: Cola Clock: Accepting Failure and Pressing On

DSCN1689Often, I am amazed at how children can take some failures and turn them into grand learning experiences.

Secondo turned nine this last week. I don’t know where the time went. Primo grew three inches since October and five since a year ago. Secondo has lost that toddler look and in those quieter moments is starting to look more like the young man he is destined to be.

The birthday wishes were simple: a Cola-Clock (i.e., powered by), a Pokemon video, time at the public pool (it was 90 degrees last weekend in Tucson), a fish tank for his bedroom with a Betta, and sushi for dinner (No, not the Betta! How could you think such a thing? You should be ashamed of yourself! Really! 😉 )

DSCN1692Assembly of the Cola-Clock went easily, and at first I was disappointed that Secondo was not interested in reading the “How it Works”-section of the instructions. Its simple, but interesting: acid on zinc and copper plates and voilà Volta! We don’t have cola (or any soda) in the house very often, so we used some 5% white vinegar. Primo was disappointed as well, so proceeded to “instruct” his brother; “No, I just want to build it now. I’ll read it later.”

In and of itself that last statement is still a blessing. Secondo is reading; and, if you have been following us, you’ll remember that he got a late start in the reading department (at least by public-school standards). I am actually quite content now as his reading and comprehension skills appear to be caught up with his peers; so, I figured I would have to take him at his word when he said he would read it later.

So, with him and Primo back into the indulgence of the Pokemon video, I tackled my latest project, the broken dishwasher, before we headed out for Sushi with Secondo.

Have I ever mentioned that I loath dishwashers? Probably not… I will have to write some on what a pain in the @#%! they are: like “Why do I need a pry bar to extricate the blasted thing from its home because the home builder doesn’t know what level really means?” But I digress… the point of this segue is that we are often faced with challenges that make us just want to call someone in to save the day, but in the end it is much more satisfying to find a solution ourselves (especially one that does not involve disassembling the kitchen cabinets and removing the countertop just to pull out a dishwasher… agh! Stop it… we’ll discuss that later)

After getting home from dinner Secondo announced that the clock had stopped. I later found it on the kitchen table, opened up and non-functional. Now he was interested! We proceeded to inspect the clock, sanded down the zinc and copper plates and refill the reservoirs with vinegar. During this time we discuss how it works and even looked up a few things about potato clocks and other similar liquid-acid batteries, but still nothing appeared on the clock’s LCD display.

Out of curiosity I pulled out the multi-meter and checked the voltage across the plates. To my amazement I was seeing nearly 6 Volts; I’m thinking out loud, “how is that possible across four plates? Well no wonder the clock stopped working, it’s only rated to 1.5 Volts.”

Secondo is only briefly disappointed, then he starts thinking about the other things he can power with his vinegar battery. I head off to the computer to look for another clock module, still puzzled about the voltage… maybe we should have used soda or lemon juice, something with lower acidity?… No, that should not have made that much difference…

DSCN1687Meanwhile, Primo and Secondo get curious; Primo rummages through the garage for some Galvanized nails and copper wire, and Secondo raids my supply of alligator clips (really, you can never have too many alligator clips!). They dip the nail and wire into a cup of vinegar and play with the multi-meter.

“Dad? We’re getting less than half a Volt.”

“Uh huh… that’s cool. I’ll be out in a second.”

Tick, tick, tick… Why can’t I find a simple LCD clock module for sale that doesn’t involve buying in lots of 10,000?



Primo: “We can’t figure out how you got six Volts?”

Secondo: “It’s less than a half.”

I plod back into the kitchen, pour some more vinegar into the reservoirs and put the plates back into place. Attaching the multi-meter I show them 6 Volts, “See?”

Primo: “Uh, dad? That’s the 2.5 Volt setting, not 10, so that is about 1.5 Volts. You’re reading the wrong scale.”

“Uh… Uh…” Dang… that’s why I use a digital meter at work.

So we started talking about it; why won’t the clock work? At this point Secondo doesn’t really care, he just wants to take it apart to see what “makes it tick”. Upon inspecting the clock to decide how we might open it, I notice a little moisture around the hole where the wires enter the module.

Secondo: “Oh, yeah. I accidentally tipped it and it spilled.”

alien_single.enMe: cue internal imagery: Silent scream… camera panning back from planet Earth… aliens on planet Vipnu looking puzzled as to the strange primal sounds emanating from some distant part of the universe.

I showed Secondo which screws to remove. Sure enough there was moisture inside, particularly across the power leads. A little paper towel and a discussion of what a “short circuit” is, then Secondo reassembles the clock module. Voilà.

What did we learn? Besides the obvious chemistry and electrical physics, Secondo and Primo both persisted in searching for empirical evidence, even designing an experiment. Me? I am satisfied with the results, but I will need to interrogate the witnesses a little more vigorously… next time… hmmm… where’s that spot light?



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