Also, the least expensive wadding is flame resistant cellulose insulation. You buy it at a building center. It’s recycled paper and bio-degrades quickly.
Do not get blow in fiberglass!
Ah yes. Cellulose insulation. Also known as “dog barf”. I have a love/hate relationship with dog barf. It is cheap. It works. But, it is messy. (But not as messy as the talcum powder on the parachute.)
Also, my experience is that hot ejection gasses sometimes escape around or through the dog barf. To remedy that problem, I have begun putting one square of Estes wadding into the tube before adding the dog barf. That square sort of “seals” the tube.
I guess that begs the question of why I don’t just use all Estes wadding and forego the dog barf? Estes wadding is not THAT expensive, after all. A little goes a long way.
In favor of using dog barf and one sheet of Estes wadding, I guess one sheet of Estes wadding plus some dog barf is still more environmentally friendly than 3 or 4 sheets of just Estes wadding as the dog barf is more biodegradable. Plus there is less “litter” on the flying field when I use just one sheet of Estes wadding and some dog barf.
I have a couple of packages of Estes wadding from the 1990’s that I still use. I have not experienced any problems when l launch rockets with wadding from those packages. I have not, however, closely inspected the used wadding when I find it on the flying field. I will try the flame test to see if the old wadding is still flame retardant.
Finally, on larger diameter rockets (BT-55 and larger), I will sometimes just install a Nomex blanket on the shock cord. More expensive and heavier than wadding but it is a non-messy, 100 percent environmentally friendly alternative to using wadding.
