<VV> What is it & where can I get some?

[NicolCS at aol.com]

<snip>
Years ago I worked for Beechcraft building King Airs in Wichita.  At the
time we used a product to protect wire bundles etc from chafing whenever
they passed in the vicinity of a sheet metal edge.  We called the stuff
"tractor tread" because that's what it looked like. Looking at a cross
section it was like a rectangular "U" shape. <unsnip>

It's called "continuous grommet".  I remember the hard nylon stuff with the 
gear teeth, here's a link to something similar:
http://mcm.newark.com/NewarkWebCommerce/mcm/en_US/endecaSearch/partDetail.jsp;
jsessionid=FJKPUYNHFIGOMCXFEOFSFGAK2URYSIV1?SKU=21-3696&N=0
This link is to MCM/Newark.  Radio Shack may have something similar. It run 
just under $10 for 100 feet. Will that be enough?  Another approach is to use 
a/c-heater hose grommets.  They fit in 1.25" openings and accomodate hoses from 
1/2" to 1" with an airtight seal by using a stretchable internal cone.  
Vintage Air and other sell them.
Craig Nicol