Hi,
Being a BAR starting the end of last season and having only lost one of the Estes micro rockets on an A10 I consider myself lucky out of the
50 or so launches attempted. Have read the FAQ's in rec.model.rockets and purchased a bale of that shredded paper insulation that is supposed to be fire-proofed. I am hoping that it would be cheaper in the long run over spending bucks for a few pieces of fire proofed toilet paper!:) (I did remember a recipe from the 1960's about soaking toilet paper in boric acid to fire-proof it. Any credence to that?) I have been pondering the situation of using the shredded stuff and hypothesize that if one pours an adequate layer of the stuff down the body tube then at the moment of ejection, the powered insulation closest to the hot gases will immediately carbonize and expand, forming a crude plug. It would then go forward to push out the parachute. I suspect one would have to put an adequate layer in the body tube so it would protect against the hot gases. I don't think I would ever be able to prove the plug theory as the remnants of the powdered wadding would probably be blasted apart in the slipstream and turned to powder/fibers again. Then again when I start using this stuff, if I see or recover a carbonized plug from an ejection that would probably support my conjecture. One problem I could portend is that by simply pouring the contents into the body tube, one really wouldn't have an idea as to how thick a layer is down there or whether or not it is adequate for ejection protection (great illiteration there) :) One work around would be to use a single layer of the tissue wadding or even use just plain untreated toilet paper, pour the insulation in the sheet to form a plug in a defined "layer" to hold the powdered insulation together. Stuff it down the tube and fire. I would think that a single layer of the flammable stuff would carbonize so rapidly that it wouldn't be able to support combustion and burn the body tube. Again I am talking about a single layer not a wad. The powdered stuff would do its' job after the single layer burned through and off course the non-flammable fibers closest to the flammable t.p.layer would fuse and help form a plug. If I or anyone was still paranoid, they could still use a single layer of the commercial non-flammable t.p. wadding. O.K. how does this sound? I know this sounds like old hat but wanted to think through this before I tried it. Anyone have any experience with this already and have they ever recovered a "fused plug" of fibers?Best regards, Kurt Savegnago NAR# 84326 Part of the reason for getting back into rocketry, is I have a beautiful launch range 3 minutes drive from my house and I don't like golf.