I was at my "local" (40 minutes away) Hobby Lobby and they had Estes standard wadding and their "Series II" wadding ($10!).
That's crazy for flame retardant Kleenex.
Any alternatives? I've heard fiberglass insulation or cellulose insulation will work well.
Any advice?
DO NOT use FIBERGLASS insulation... the stuff is NON-BIODEGRADABLE and it will still be laying there 100 years from now... matted and washed flat and probably embedded with dirt, but the glass fibers themselves will still be completely intact... fiberglass insulation poses a threat to anyone else using the property-- from kids who may play with it or folks who might step or sit on it and get fiberglass fibers embedded in their skin (and thus get the "fiberglass itchies" and skin irritation, to animals that may ingest the fiberglass accidently which can seriously injur or probably kill the animal... grazing animals are particularly susceptible! Other artificial disposable fibers like pillow ticking or mattress ticking (stuffing) are also non-biodegradable and will contaminate the flying site...
If you want a CHEAP substitute for wadding, use CELLULOSE BLOW-IN HOUSE INSULATION... also called "dog barf" by rocketeers... this is available from your local big-box indoor-lumberyard type home-improvement store, packed in big bales or blocks wrapped with plastic. If you check, sometimes they'll have a bale or part of a bale laying around from the dumb guy running the forklift who shouldn't be, who's speared a bale and punctured the plastic, or from leftover stuff in the machine when someone brought it back after renting it to blow the stuff into the walls of his house and not cleaning it out properly... these can usually be gotten VERY cheap, although just buying the bale outright at full retail won't set you back much... (usually $4-8 bucks or so...) This will provide a veritable LIFETIME of rocketry wadding... Since the stuff is actually shredded recycled newspaper and phone books and such, it's completely biodegradable. It's treated with the same sort of borate fireproofing (flameproofing, fire retardant) chemicals that are applied to Estes style wadding... just stuff some of the it into the rocket about 2-3 times the rocket diameter fairly loosely, and then install the recovery device, shock cord, and nosecone, and you're ready to fly... Another thing that's nice about this stuff is, when it blows out, it's basically CONFETTI-- it usually rains down in a pretty wide area, and is SO widely dispersed and pretty small particles, so it rapidly disappears into the turf or soil after a little exposure to wind or rain. As most soils in the US are actually boron deficient, when the particles break down into humus in the soil and release their boron, the boron is actually a fertilizer... so it's actually GOOD for the environment! Estes wadding will do the same thing, BUT, since it's usually in the form of wadded up "kleenex sheets", it will lay around on top of the grass as "litter" for a pretty good while before rain or a storm finally works it down to the damp layer at the soil surface and it starts to decompose... the finer particle size of dog barf allows this to happen almost instantly to within a couple days...
Other alternatives to dog barf or sheet wadding exist as well... some are "reusable" or do away with wadding entirely, like baffles... but usually even with a baffle most folks wrap the parachute in at least ONE sheet of wadding just to "make sure" it doesn't get singed... Nomex cloths can be installed over the shock cord (or tied on with small ring or bit of kevlar string or something) for reusable wadding... sometimes ironing board covers can be used, but be careful-- not all are as "flameproof" as they're supposed to be... (especially if they have the mark of quality on them that says "China"...) For years folks used crepe paper for streamers and for wadding substitute, since crepe paper is required by law to be flame retardant... but again, some has turned up that is far less 'flame retardant' than it should be, usually from ultra-cheap sources.
Even green leafy vegetation has been used successfully for wadding... tear off a few handfuls of lush green grass and stuff it in your rocket like dog barf-- the high moisture content prevents the grass from being ignited by the ejection charge hot gases and burning BP particles-- or you can use lettuce or cabbage leaves... some folks use popcorn, but popcorn CAN burn... so I don't recommend it...
Another alternative that Micromeister here on the forum has presented involves making 'pom-poms' out of regular cheap white Teflon Plumber's Tape... available just about anywhere... tear it off into strips several inches long, laying them out on top of each other in a starburst pattern overlapping the center... once you have a bunch of strips, grab it near the center, and tie some string around them all tightly in the center to make the pom-pom... then tie it onto the shock cord... the teflon plumber's tape is very heat-resistant and acts as wadding when shoved down into the tube, protecting the parachute or streamer from the ejection gases and burning particles. Just make sure the pom-poms are tied to the rocket, as they too are non-biodegradable and fully reusable-- just shake out the crap from the ejection charge and stuff it back inside...
Another material commonly used, especially by competitors, is foam plugs... basically these are plugs of foam cut from pink or blue house foam insulation using a hard body tube or similar size pipe to "cut through" the foam and make the plug. This is basically a variation on the "ejection piston" idea, which uses a piece of tubing slightly smaller than the inside of the rocket (so it can slide easily, not a tight fit like a tubing coupler) fitted with balsa disk or pair of disks to form a "piston" which is connected to the shock cord, thus being between the ejection end of the motor and the recovery device above... If you use foam plugs, competitors will usually just eject them from the rocket and let them flutter down on their own-- IMHO this is irresponsible, because the foam isn't biodegradable either (though it will break down with long-term exposure to UV in sunlight) and will be "litter" on the launch site... IF you choose to use a foam plug for an ejection piston, tether it to the shock cord by taping a piece of thread to it and tieing it to the shock cord, or run a needle with a bit of string through the foam plug, take the needle off, and tie the string to the shock cord or parachute... the weight will be minimal and this will keep the foam plug with the rocket, preventing the litter problem, which will make your launch site landowner much happier... Pistons, of course, are tied to the shock cord and stay with the rocket, as they're reusable...
Later! OL JR
PS... you CAN reuse Estes wadding... I go around the field a day or two after the launch and pick up all the Estes wadding I can find (which helps since I live on the farm the club flies from) and stuff it in my pockets... drop it in a plastic bag in your launch box when I get back to the house...
Some of it will be partially burned or singed, some will have holes burned through it... use this stuff closest to the motor, and put less burned or unburned stuff near the top by the parachute... the burned stuff will take the brunt of the blast from the ejection charge, and probably be darn close to confetti after another launch, but the stuff higher up will catch anything that gets through and keep the chute from getting burned... and if you can find it, you can use it AGAIN down by the motor!
