Using Old CD's as Reflectors?

On Sat, 14 Feb 2009 00:19:14 +0000, Peter Grange wrote:


Not bicycle related, but I saw several Wannado installation CD's
strung between fruit trees as bird scarers in a garden in France a few
years ago.

Unless French birdies are different, it doesn't work in my
Australian garden.

On 2009-02-14, sergio wrote:
On 13 Feb, 19:59, Ned Mantei wrote:
Not bicycle-related but at least road-related: I often see them swinging
in the breeze, hanging from tree branches or metal posts, where roads
pass through a forest. I think the idea is that a reflection from
headlights will help keep a deer from crossing the road as a car
approaches at night.
Ned in Zurich

I have seen them hanging from trees and from fence posts on the side
of roads in the Simmenthal region, and wondered what they were for. I
fancied they might be like the flags in the Himalaya.

Sometimes they are also used to scare birds.

terryc wrote:
:: On Sat, 14 Feb 2009 00:19:14 +0000, Peter Grange wrote:
::
::
::: Not bicycle related, but I saw several Wannado installation CD's
::: strung between fruit trees as bird scarers in a garden in France a
::: few years ago.
::
:: Unless French birdies are different, it doesn't work in my
:: Australian garden.

The idea is for there to be a sufficient number for them to twirl in the
wind. It's the shiny movement that birds don't like. The discs have to be
hanging freely and moving quite a bit.

Pat

From the original poster:

Thanks for these ideas. Now I have an idea of what to do with about a dozen
of them. As far as the other several hundred, I decided to ship them off to
a recycler in California. It cost me $9 and half a roll of packing tape,
but they assure me every usable component will be recycled.

(PS: There's no sensitive data on any of the discs.)

TM

On 14 Feb 2009 05:59:28 GMT, terryc
wrote:

On Sat, 14 Feb 2009 00:19:14 +0000, Peter Grange wrote:


Not bicycle related, but I saw several Wannado installation CD's
strung between fruit trees as bird scarers in a garden in France a few
years ago.

Unless French birdies are different, it doesn't work in my
Australian garden.

Maybe it was the content then :-)

On Sat, 14 Feb 2009 10:12:12 -0500, "Papa Tom"
wrote:

From the original poster:

Thanks for these ideas. Now I have an idea of what to do with about a dozen
of them. As far as the other several hundred, I decided to ship them off to
a recycler in California. It cost me $9 and half a roll of packing tape,
but they assure me every usable component will be recycled.

(PS: There's no sensitive data on any of the discs.)

TM

Dear Tom,

I couldn't help wondering about the costs for shipping several hundred
CDs to California for recycling.

A typical CD weighs about 16 grams. If "several hundred" means ~500,
that's 8,000 grams or ~18 pounds of polycarbonate plastic onto which a
very thin layer of aluminum has been sprayed, and then covered with an
even thinner layer of lacquer, plus ink of various colors:
http://en.wikipedia.org/wiki/Compact...ysical_details

There isn't enough ink and lacquer to be worth recovering.

The polycarbonate isn't worth much more--after all, a CD costs about a
quarter at the store, scarcely any of which is for the materials.
You're payihg for high-precision processing of cheap materials, plus
shipping, packing, and marketing.

It's the aluminum that's valuable. Recycling centers pay a little less
than fifty cents per pound for raw aluminum cans plucked from the
trash because it's by far the most valuable material for recycling.

So how much aluminum is there in an approximately 16-gram CD?

I couldn't find that information quickly on the internet, but I've got
an electronic scale, so I cut out a piece of aluminum foil in the
shape of a CD and weighed that.

True, aluminum foil is probably _much_ thicker than the layer sprayed
onto a CD, so we'll end up with an exaggerated value for recycling.
But the aluminum foil was handy and the exaggeration should cover
whatever tiny value is being overlooked in the polycarbonate, lacquer,
and ink.

On my scale, a brand-new Memorex CD weighs 15.1 grams.

A piece of aluminum foil cut to the size of a CD weighs 0.4 to 0.5
grams. Let's use the higher figure, 0.5 grams.

500 CDs x 0.5 grams aluminum/CD = 250 grams of aluminum

That 250 grams of aluminum is about half a pound.

At less than half a buck per pound down at the recycling center, that
means that there's about 25 cents worth of aluminum in 500 CDs.

And that's if it's as economical to separate the aluminum from the
comparatively huge bulk of polycarbonate as it is to handle raw
cans--recycling cans would cost a lot more if each can was _filled_
with solid plastic that couldn't be crushed and had to be separated.

For comparison, prices for most other common recycling materials are
per ton, not per pound. A realy good price of well-sorted green glass
is around $50 per ton, which works out to 2.5 cents per pound.

So you used your time, $9 worth of shipping and its inevitable
byproducts, and half a roll of non-recyclable packing tape to send 500
CDs to California, where they might produce 25 cents worth of aluminum
(a generous estimate).

At the price of a roll of packing tape, this sounds like a losing
proposition, both economically and in any recycling terms. You might
as well have shipped a piece of rusty muffler to the steel mill here
in Pueblo.

But you enjoyed the process, and I had fun thinking about it.

Cheers,

Carl Fogel

LOL. Thanks, Carl. I needed that chuckle today. It's also good to see
that somebody else has a lot of spare time on his hands these days.

I spent the better part of ten years accumulating these discs and the better
part of five years trying to figure out what to do with them. I did all
kinds of experiments with stacking them up and shining light through them,
trying to arrange them on a wall of my recording studio, etc. Nothing was
worth the effort.

Then I started looking into ways to use them on my bikes. I tried inserting
some in the spokes to reflect headlights from cross streets, but that seemed
to create a potential for jamming one of the wheels when a disc slipped or
cracked or whatever. Then I thought about using one as a front reflector,
since the rear reflector needs to be red. But when I experimented with
that, I discovered that a standard reflector works much better. Finally, I
thought about developing some type of night-riding vest covered in these
reflective discs. I was hoping someone on this group would suggest
something like that and legitimize my idea, but it didn't happen.

So when this recycling opportunity came along and I was going stir crazy
from having virtually no business on the books, I just packed all the discs
in a box and headed to the post office without giving it a second thought.
It was only after I met a friend on the way out and told him about what I
had done that I realized what a waste of nine bucks that probably was. I
spent the next couple of days talking myself into believing that, while it
may have been a dollars and cents mistake, at least I had made the right
choice for the environment.

Then YOU came along and made me feel like crap again. Thanks...

Papa Tom wrote:
Has anybody figured out a good bicycle-related use for old CD's and DVD's
yet -- perhaps as some type of reflector?

I am one of the gazillion people sitting on a stack of useless discs -- the
results of bad burns or outdated software content -- and I am just waiting
for the ultimate recycling idea to come along.


Not really bicycle related, but I had become tired of open plan living
and wanted an inexpensive solution. I used the thousands of data
back-up and advertising CDs I had accumulated, just stacked them up and
drilled them with four 1/8" holes near the perimeter and wired them
together as room dividers, drapes and doors.

My latest project is a giant disco ball for the backyard, I plan on
hanging it from a large walnut tree and illuminating it with discarded
bicycle head lamps.


Marcus
Re-use, recycle and cycle and cycle.

On Sat, 14 Feb 2009 16:11:29 -0500, "Papa Tom"
wrote:

LOL. Thanks, Carl. I needed that chuckle today. It's also good to see
that somebody else has a lot of spare time on his hands these days.

I spent the better part of ten years accumulating these discs and the better
part of five years trying to figure out what to do with them. I did all
kinds of experiments with stacking them up and shining light through them,
trying to arrange them on a wall of my recording studio, etc. Nothing was
worth the effort.

Then I started looking into ways to use them on my bikes. I tried inserting
some in the spokes to reflect headlights from cross streets, but that seemed
to create a potential for jamming one of the wheels when a disc slipped or
cracked or whatever. Then I thought about using one as a front reflector,
since the rear reflector needs to be red. But when I experimented with
that, I discovered that a standard reflector works much better. Finally, I
thought about developing some type of night-riding vest covered in these
reflective discs. I was hoping someone on this group would suggest
something like that and legitimize my idea, but it didn't happen.

So when this recycling opportunity came along and I was going stir crazy
from having virtually no business on the books, I just packed all the discs
in a box and headed to the post office without giving it a second thought.
It was only after I met a friend on the way out and told him about what I
had done that I realized what a waste of nine bucks that probably was. I
spent the next couple of days talking myself into believing that, while it
may have been a dollars and cents mistake, at least I had made the right
choice for the environment.

Then YOU came along and made me feel like crap again. Thanks...

Dear Tom,

Cheer up--it could have been worse.

Years ago, one of my clients, an otherwise sensible office manager,
developed what some might call an obsession with recycling paper.

She set up a special box for half-a-dozen busy clerks to visit and
deposit the torn-off tractor-feed strips from dot-matrix paper.

The idea, as I recall, was that the torn-off tractor strips were clean
paper, free from any ink, and would be much more valuable.

Here's a cheerful 5-minute experiment in just how far the recycle
business can go, conducted by Penn & Teller:
http://www.youtube.com/watch?v=SC3CZBDz7Wg

That was a recycling hoax in the USA.

In the UK, some people can only wish that such things were a hoax:

http://www.dailymail.co.uk/news/arti...st-inches.html

Cheers,

Carl Fogel

Those are the types of things I was trying, but nothing seemed worth the
effort. I was hoping to invent a breakthrough product for bicyclists, but I
guess it isn't going to happen any time soon!