Mike wrote:
So, does this mean that my potato cannon constructed out of schedule 40
PVC is now to be considered "unsafe"? I wrapped a few layers of duct
tape around the combustion chamber, just in case of a blow out - no
problems yet.

BTW, I've got a great book on the subject called "Backyard
Ballistics". All kinds of fun projects involving PVC.


When I worked for the railroad the car knockers would drop a lit fusee
into a pipe they had rigged up to a glad-hand and kick the valve on the
ground air open.

Probably got a good 100 ft or so altitude ... maybe twice that
horizontally.

;-)

I think that they used them to signal each other. The fusee goes out
when it strikes anything hard (a gentle sideways tap is sufficient to
extinguish them) so they are actually pretty safe for that use.

Bill