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Summer 2004: Everything You Ever Wanted to Know about Foam, but Were Afraid to Ask!
Hello, fellow campanologists and handbell enthusiasts! Professor Handbell here with more in-depth insight on the inner workings inside the world of handbells (from a scientific perspective, of course!) This time out, we’ll take a look at a subject that usually doesn’t get much coverage. Actually, come to think of it, it is something that stays covered most of the time. I am talking, of course, about foam. The more astute readers probably garnered that from the title!
Foam plays an important, albeit often overlooked, role in handbell ringing. Most obviously, foam protects your bells from the table. I mean, could you imagine laying your beautiful, bright, bronze bells directly on that hard table?! Ouch! Also, there are several ringing techniques – Martellato and Table Damp, most notably – that actually use foam to create a distinctive musical sound.
Looking at things scientifically, our next question is: “What exactly is foam, and how is it made?” The foam we use in the handbell world is actually Flexible Polyurethane Foam (which we’ll shorten to “FPF” for brevity’s sake). FPF’s main use is in cushions for the furniture industry. Chances are that chair you are sitting in right now is padded with FPF! The properties of the foam itself may be a little different than what we use, but we’ll get to that a little later. FPF is also used in pillows, insulation, flotation devices, carpet underlay, and even in the Space Program! In fact, a blended Foam-In Place system has been on every Space Shuttle flight since 1983. Pretty cool!
So how exactly is foam made? Suffice it to say that there is a lot of chemical mumbo jumbo that goes on: blending one liquid chemical with another liquid chemical to cause a reaction (trust me… it’s all VERY scientific). Carbon dioxide is released during this reaction and the bubbles become trapped as the liquid solidifies… FOAM! This is then cut to size using a saw, the end product being what you see on your handbell table!
The physical properties of FPF can be altered, thus separating handbell foam from that used on your couch or on the Space Shuttle. For example, the greater the foam’s density (the weight of one cubic foot of foam), the better its quality. So while our foam is not as dense as the foam needed for space travel, it is about the same density as that used to make furniture. Another important property of foam is Indentation Force Deflection (IFD). Simply put, this is a measure of the firmness or softness of foam. If your foam is too soft, your bells roll in toward each other. Not good! Too firm, and the foam does not offer the padding you need. You can see why IFD is so important!
Other changeable physical properties include resilience (liveliness or springiness of the foam), static fatigue (a measure of the degree of softening that can be expected over time), and tear resistance (you can figure that one out for yourself). And you thought your foam was just a big cushion!
A final recommendation from Professor Handbell: When it comes to foam thickness, the thicker the better. 2” is for CHIMES ONLY! 3” is acceptable for bells, but watch yourself on any table techniques. Finally, 4” provides maximum protection for your bells, while allowing you to do techniques without much worry.
So, there you have it! You didn’t ask, but now you know. Feel free to use these foam facts to impress friends, family, and fellow ringers. You’ll be the hit of every social engagement! This is what makes Professor Handbell so popular at parties. Well, that and his rugged matinee-idol looks, razor sharp wit, good grooming habits, etc. I’m sure Mrs. Professor Handbell would agree! Anyway, until next time, I remain