photo sharing and upload picture albums photo forums search pictures popular photos photography help login
jCross | all galleries >> What I Did Today >> What I did Today 2013 > April 4, 2013
previous | next
04-APR-2013 jCross

April 4, 2013

130404_0008P.jpg

Well, it's that time of year to start annual inspections of my airplanes. Today I got the wheels and brakes done for the Swift. Had to replace left tire and I decided to put a new tube in as well. I am converting to all butyl rubber tubes each time I change one. Butyl holds air a lot better than any others.

Canon PowerShot G1 X
1/60s f/5.6 at 15.1mm iso200 full exif

other sizes: small medium large original auto
comment | share
jCross08-Apr-2013 10:28
John: My last assignment at Exxon was Director of Butyl Polymer Product Development. What keeps your tires rock hard nowadays is a halo butyl rubber coating on the inside of the tire, called the innerliner. In the old days, inner tubes were made of natural rubber which leaks air through the rubber quite rapidly. The difference in molecular structure of the polymer makes a big difference in the air permeability.
John Cooper08-Apr-2013 01:17
John, I brought a bottle of some gungy stuff to put in my push bike tyres.
It is supposed to stop small punctures.
I do know for sure that it stops the air slowly leaking out of the tubes.
Where I used to top up the pressure often, they stay rock hard now.