Punk Rock, Longboards and Mad Science

Longboard and Gas Laws

What am I doing to help kids achieve?

How do I know when they are there?

What is the evidence?

  It all started with a class my son and I took together at . To make a long story short, we started on a Saturday morning with nothing and left Sunday afternoon with a custom built longboard. (Think skateboard but...well...longer). It was a great class taught by . So what does this have to do with chemistry? The word spread after we got home. Nephews, nieces and friends wanted one. My princinpal even said, "Hey, we have a handful of kids who love skateboarding that we are trying to reach. Ever consider starting a club?" (That tends to be code for "Thanks for volunteering...") So the challenge was on. Would it be possible to make a decent longboard without a gold plated workshop and a master craftsman standing over my shoulder to answer any and all of my questions? Maybe...with the help of a little science...

  Most modern skateboards or longboards are made by a process called bent lamination. Essentially it consists of taking thin strips of wood called "veneer" and gluing them together. It is similar to creating homemade plywood. This has a couple of advantages. First, the process produces an extremely stable strong product that does not expand or contract in different weather and usually bends but does not break. Think "material science" in action. Another advantage is that once the veneer "sandwich" is glued together and before it dries, it can be placed over a custom styrofoam form. It will dry in the shape of the mold. It is much easier to shape and curve wood this way than to do the same with a large chunk of wood that would need to be steam bent or sculpted. There are also a great gas law applications in the process. The veneer sandwich and mold are placed in a thick plastic bag, sealed and the air is pumped out of the bag. In theory, the column of air above the bag is pushing down with a pressure of about 12 to 14 pounds per square inch. This is great for clamping the curved veneer to the mold. There is a problem. Most vacuum systems with the bag can run close to $1000. That is a big chunk of change for one skate board. However, there is a company in Canada called . Here is the genius behind their system called the "Thin Air Press". They provide a thick bag that has a tar like substance that completely seals the bag and a one way valve used for evacuating the air. A person can place the veneer and mold in the bag, seal it and start to pull most of the air out with a shop vacuum. This will not be enough. The shop vac pulls a large amount of air out quickly but it is low pressure. To get to higher pressures required for the pressing, there is a hand pump that takes small amounts of air out slowly but a person can get to higher pressures. Once most of the air is out, atmospheric pressure takes over and clamps down the veneer. It is only required initially for a person to check back every few minutes to make sure there is not a leak in the bag.The total time to evacuate the bag and get a good seal usually only takes a few minutes. The bag does not evacuate air to the degree of a professional system, but it gets pretty close, is a tenth of the cost and is "good enough". It is great to see gas laws and air pressure at work.

  Once the board is out of the bag, work is done to cut and sand it to its final shape. The problem now is the art work that is placed on the board or what people call the "deck". Honestly, I have little to no art ability. I do know something about intermolecular forces and chemicals. came across a simple and inexpensive way to transfer images from an ink jet printer to a piece of wood. It is all about utilizing the intermolecular forces involved. Steve takes a sheet of labels from a office supply store and takes off all the labels but saves the paper that was attached to the labels. The paper is really similar to a stiff wax paper and seems to be extremely nonpolar. Ink from the printer, on the other hand, is pretty polar. Steve feeds the label free wax paper into the printer, wax side up. The ink is on the paper but is wet and does not stick. He then carefully and quickly places the ink side of the paper on the wood. The somewhat more polar fibers of the wood immediately bond with the ink and the image is transfered to the wood. It pretty much soaks the ink up like a sponge. Next, a coat of polyurethane is placed on the wood. The polyurethane over time reacts with oxygen and the polyurethane chains are made even longer and with more tangles. The resulting coat is chemistry at work again. The result is long tangled polymers which end up being similar to coating the board in a protective plastic. This method works amazingly well. My nephew is a huge fan of the band They have some great looking film noir type concert posters. I used this process to place these posters on the longboard and it turned out great. Caution... more chemistry occurs with polyurethane than most people know. Oxygen reacting with polyurethane is an exothermic reaction (again...more chemistry). There have been reports of people taking rags soaked in polyurethane and just throwing them in a trash can. In some cases the polyurethane reacts with oxygen and produces enough heat to start a fire...especially if saw dust is around.

     Next, it is time to put on the wheel assembly or what the skateboard community calls "trucks".  The key is to get the trucks placed exactly in the middle of the board at both ends.  Suppose you are dealing with some kids who hate math.  How do you teach them to use something they hate?  Simple. You cheat and use geometry and don't tell them it is math.  The ancient world build some pretty cool structures and never used tap measures and auto cad. How did they do it?  I do not have all of the answers but have most of them. For centuries people built tables, chairs and buildings really well without ever using a ruler. Instead they used a sector, a divider and simple whole number proportions. Jim demonstrates in this video called  how to quickly, easily and efficiently find the center of any segment, such as the width of a longboard, faster and probably much more accurately than I could ever measure with a tape measure. It utilizes similar triangles and works like a charm. It can get the dead center every time within seconds.

     Why bother will all of this???  I just had a conversation with a passionate teacher and good friend who really cares about her students.  She is struggling.  She sees the value of chemistry but how do you really convey that to a teenager that this "stuff" is important?  Why should a kid care?  What if that kid could use gas laws, chemical reactions, geometry and material science to make a really cool longboard that was custom built and their very own? Would they care then?  The job we do is hard and somedays feels like it is impossible.  We cannot always be reinventing the wheel.  This time now might be the right time to "tweek" a few things and try something new that might reach the kid that people may have thought could not be reached.  It can be fun, exciting, I get to learn new things, most importantly kids might get excited and when I test out the board, fall and break my arm I will be able to tell the doctor...."It's O.K....I'm a science teacher..."

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