usapyro Posted June 11, 2011 Posted June 11, 2011 (edited) I couldn't find a thread on this so I decided to start one in here as it should be helpful information to people in rocketry too. What do you need to treat the paper with in order to make sure it won't burn up? I am actually not going to be using these parachutes for rockets. They will be attached to smoke canisters that are shot out of a mortar and eject a parachute at around apogee. (Can't figure out any other way to get legendary smoke bombs not to burn to the ground... LoL!) My idea that I am about to test that will probably fail is to make a baking soda solution and soak a paper towel in it. Then attach heavy duty woven fishing line to the four corners... Not sure about the square parachute design... Hum... Edit: Also, I just found information on using Alum (Household pickling stuff)... However I have no idea if that stuff will make the paper too stiff to unfold? I will be H3 to eject the parachute because it usually doesn't even set paper on fire. The smoke will be coming out of the bottom of the canister while the parachute will shoot out of the top end. Kinda complex design that requires some duct tape protected quickmatch running down the outside from the parachute burst and a side time fuse for the parachute deployment. Edited June 11, 2011 by usapyro
dagabu Posted June 12, 2011 Posted June 12, 2011 (edited) Fishing line and paper towels will not work. Try cotton broad cloth treated with borax and NOMEX string or other fire retardant string. If you are intent on making parachutes, I suggest a shotgun sabot design that I was told of over on Passfire. Make or use a tube (1" works well for me) cut a disk 3/4" round, cut three strips of 30# kraft, 3/4" wide by 3x the length of your cavity, glue them on the bottom of the disk at 120° offsets and push the wadding into the tube. This is a real quick and dirty mock up of the sabot: http://www.pyrobin.com/files/100_2336.jpg http://www.pyrobin.com/files/100_2337.jpg This isn't the way I make them in the picture above, its just a mock up to show you how the leaves overlap the center and protect the insides from fire. You still need some paper wadding to protect the bottom of the sabot. You will find some ideas below. BORAX -dag Edited June 12, 2011 by dagabu
guntoteninfadel Posted June 12, 2011 Posted June 12, 2011 Kinda complex design that requires some duct tape I do like where this is headed
usapyro Posted June 12, 2011 Author Posted June 12, 2011 I do like where this is headed That stuff is awesome. The military has even used it to tape hovercrafts back together temporarily...
Arthur Posted June 12, 2011 Posted June 12, 2011 You can help preserve the parachute by careful preparation if the paper and by separating the paper from the fire using wool wadding or plain rice hulls. Sometimes the chute strings are made of wire or have a wire leader near the hot side.Shimizu has lots of information in his books.
usapyro Posted June 16, 2011 Author Posted June 16, 2011 (edited) use ALUM Dagabu's method combined with Alum works good. Rice crispies barrier against the burst works a little better for me though. I have had that damn cardboard plug with it's tendrils get tangled in the parachute once... I kinda decided I prefer white cotton string treated with Alum and paper treated with Alum barricaded from direct flame by a filler like rice crispies. I actually even got this to work with untreated paper and braided fishing line too... Althought thats not perfectly reliable... LoL! You guys need to experiment with H3 sometime... You can burn 20 grams in a paper cup and the paper cup won't even be burned... Weird how little heat it conducts with low pressure. Edited June 16, 2011 by usapyro
layedbackkustomz Posted June 17, 2011 Posted June 17, 2011 here ya go. back in my high powered rocketry days we us to have to make our own wadding because of how much we used and the cost. so we would take sodium bicarb.(baking soda) and water and soak blow in insulation for your attic.it worked get so we figured if it will work for that lets soak some paper in it and make a parachute for a estes rocket. so we soaked then carefully pulled out the paper and spread it out to dry. it worked also.now heres a tip(when folding the chute sprinkle talc/flour or corn starch on the chute it will help it deploy and keep it good for longer term storage. now i remember i got some parachute rockets and after i chased down the chute it was a tissue paper chute and i have a feeling it was soaked in a sod. bicarb mixture. also theres shells i have seen with paper chutes. I hope this helps LBK
Mumbles Posted June 17, 2011 Posted June 17, 2011 Being fairly non-compressible, I'd imagine rice crispies would make a pretty poor fireblock. Something like rice hulls, or usually saw dust are much more traditional.
usapyro Posted June 17, 2011 Author Posted June 17, 2011 Being fairly non-compressible, I'd imagine rice crispies would make a pretty poor fireblock. Something like rice hulls, or usually saw dust are much more traditional. The brand of rice crispies I use are like little thin hollow squares. They are not the traditional puffed rice type. I think these are made from flour.
madmandotcom Posted June 30, 2011 Posted June 30, 2011 i dont think theyll be flour, ive seen people do cremoras with flour
dagabu Posted June 30, 2011 Posted June 30, 2011 i dont think theyll be flour, ive seen people do cremoras with flour MMDC, Flour is a main ingredient in almost all cereals, "Flour is a powder which is made from grinding cereal grains, other seeds, or roots. It is the main ingredient of bread, which is a staple food for many cultures." In this case, he is speaking of the final product that the flour combined with water and other ingredients and then extruded, cut and dried make, not the raw powder. Mum, two weeks?!? Please? You promised!!!!!! -dag
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