Thanks for Asking!
1) Can dried out rosin be 'reconstituted'? - such as by heating, or
additive? It seems that once dry & hard, it's useless. I can't get
any to come off & stick to my fake horsehair bow.
It's possible to scrape the rosin cake with a flat blade in order to
powderize a layer of it for use, even when very dry, however this may
not provide the degree of tackiness you require for the best sound. I
know rosin users who store their rosin in zipper plastic bags, or
small, tightly closed plastic containers to help it remain useful
longer. It is also possible to reheat and recast bow rosin. This
excerpt by cellist Terry Mauric describes the process.
"Rosin is a naturally occurring resin derived from pine trees and it
is a thermoplastic material; that is it can be melted and reset. When
it is melted it is fluid, but of a fairly high viscosity. I have, in
the past, melted down my old rosin cakes to make a “new” one. I simply
poured the melted rosin into a tin lid and let it set. When rosin
cools it forms what is known as a glassy polymer, which, for all
intents, is a fairly hard and un-reactive material, something akin to
window glass, which is the classic glassy form of silicon dioxide or
sand. Glassy polymers have a point at which they soften and become
“rubbery” or soft. The glass transition point is known as Tg. Some
glassy polymers also exhibit the ability to crystallize, but cannot do
so until the glass transition temperature, Tg, is reached. Tg, can
however, be lowered by the addition of plasticizers and this is the
basis of the texture and feel of many synthetic materials that we use
daily. So the addition of a plasticizer can lower the glass transition
temperature of rosin to a point where the material is in the "rubbery"
or sticky zone."
The full forum post further describes the materials chemistry. You'll
find the post by scrolling about one-third of the way down the full
page located at:
http://www.cello.org/heaven/mbarchs/2001/june2/rosin.htm
However, you should be cautioned that bow rosin, as a resin product,
is highly flammable. It has been known to spontaneously combust
without any heating whatsoever. Newport Glass publishes a Material
Safety Data Sheet for gum rosin that suggests the following
precautions:
Work in a well ventilated area.
Do not breath vapors if melting or softening material.
A cover should be over the melting pot & an exhaust hood used.
Have a dry chemical fire extinguisher available in the immediate area
if heating, softening or melting the material.
You may read the full safe handling information at:
http://www.newportglass.com/amsgrosn.htm
Traditional rosin is also manufactured in a powdered form, an
alternative to the traditional cake. Two online purchasing sources for
Geipel Powdered Rosin are available:
http://www.tonewood.sk/12.php?od=0&avail=122&ia=1&na=1&sn=270501#1
http://www.cellos2go.com/rosin.htm
2) Aren't there alternative technologies to real/artificial horsehair
& rosin? - such as some natural or man-made material that would excite
the string as well if not better and not require rosin?
Synthetic resin is available from ClearToneTM. An online information
sheet details the differences between traditional rosins and
ClearTone:
The comparison of ClearToneTM's susceptibility to oxidation states:
"[Traditional] Rosin is very reactive to oxygen and in its fine
powdered form on bow hair will oxidize and lose its tack in a matter
of days. This causes buildup of useless powder on bow hairs. Rosin is
so unstable, that bags of flaked rosin have been known to
spontaneously combust."
"ClearToneTM is extremely resistant to oxidation. Where rosin powder
oxidizes in a matter of days, ClearToneTM. will resist oxidation for
months. It keeps its useful tack for a long time and does not build up
on bow hairs like rosin does."
I'm not able to locate an online purchasing source for ClearToneTM,
nor does the one music supplies dealer I found open on Memorial Day
weekend have it available, however, he offered to search his catalogs
and call me back if he located a source. I'll post a clarification if
I hear back from him. You might also inquire at your own supplies
dealer.
Current trends in bow materials are still focused on horsehair and
synthetic alternatives of horsehair. Traditional bow craftsmanship is
focused on technical analysis of currently used materials, and seeking
global sources for the best products available. An example of modern
technology applied to the analysis of bow hair may be found at:
http://iwk.mdw.ac.at/english/research/bowhair/bowhair.htm
A bit of thought seems to be heading toward completely new instruments
for the 21st century, and digitizing string sounds and voices. Here is
a treatise on 21st Century Instruments, which contains predictions and
suggestions for stringed instruments. The introductory page offers a
link to the full study as a zip file in Excel or Word formats:
http://www.c21-orch-instrs.demon.co.uk/
Research and experimentation into the reproduction of the SOUNDS of
bowed strings is available in this technical document entitled
"Nonlinear Commuted Synthesis of Bowed Strings", which suggests that
future stringed instruments might more likely be digitized rather than
physically played as traditional bass and other instruments have been
played in the past and are still played today. The document is
available in PDF format:
http://www-ccrma.stanford.edu/~jos/ncbs/ncbs.pdf
Experimental musical instrument links offer many exploration
possibilities. Several of the sites, though not containing specific
information about stringed instruments, offer some fascinating
information and speculation about traditional instruments using new
materials and technologies.
http://www.windworld.com/emi/links.htm
I hope this information is useful to you. If you'd like clarification
of any portion, please feel free to ask.
Thank you for using Google Answers.
~larre-ga |
,
0 Comments
)