----- Original Message -----
Sent: Saturday, February 08, 2003 4:09
AM
Subject: ShopTalk: A Stupid/confusing
Experiment
Hi Folks,
You can tell it's really cold in Wisconsin and I've got too
much time on my hands.
I've always wondered why some graphite shaft manufacturers
paint their shafts to look like lolly pops. It always seemd to me that the
advantage of graphite was it's very high stiffness relative to its weight
(Young's modulus). I assumed the Young's modulus of paint has got to be pretty
damn low. I took a perfectly good orange painted Micro 58 that was being given
away at the PCS and decided to sacrfice it in the name of
science.
I took a whole bunch of measurements on the this very fine
shaft and then removed all its paint! I tried MEK, toulene, lacquer thinner,
varnish remover and some paint remover that smelled like oranges. Nothing
touch it! I finally had to scrape all the paint off. (I was very careful not
to damage the ghaphite when I removed the point. ) Apache really knows how to
paint a shaft. With the removal of the paint the weight of the shaft of course
went down. This should have increased the frequency of the shaft. The damping
effect of the paint should also have resulted in an increase in cpms with the
paint removed. Here's what I got:
The shaft initially weighed 64.9 grams. The paint was 0.015"
thick (diameter) at the tip. The frequency was carefully measured. Before
removal it ranged from 254.8 to 258.0cpm in the weak and strong planes of the
shaft. After I removed the paint the weight dropped to 60.6 grams. The paint
had added about 7% to the weight of the shaft. Now for the weird stuff. The
frequencies of the nude shaft were now 253.7 and 256.2! The frequency went
down. I guess the paint did add some stiffness. I would not have guessd it.
Has anyone tried making shaft out of paint? To hell with all
the fancy epoxy wraps.
Anyone interested in a rather odd looking Micro
58?
Cheers,
John K
