hondo Posted November 2, 2007 Posted November 2, 2007 What is a good delay composition for black powder core burning rockets, and can someone give me directions so I can add headers on my 1 pound rockets so they go off at the top of flight, I hate to spend 55.00 for a book to get one question answered
NightHawkInLight Posted November 2, 2007 Posted November 2, 2007 I use black powder with various percentages of baking soda added depending how much delay I want. 40% baking soda is pretty much the maximum. I'd go for a half inch of 25% and see how that works out. Should get you around 2 1/2 seconds.
mormanman Posted November 2, 2007 Posted November 2, 2007 or; you make some BP but don't mill it. Green mix. You can just use the TT star mix. Baking soda is hydroscopic though.
hst45 Posted November 2, 2007 Posted November 2, 2007 hondo, it's actually impossible to tell what EXACTLY you should do since there are too many variables that we don't know, such as what tooling you are using, what is the speed of your fuel, etc. For my 1lb core burners I use Greg Boyd's tooling, a 60/30/10 fuel with maple charcoal, fresh step cat litter nozzle (no kidding, try it), and for me a half inch of the same mix cut with 15% baking soda works. The other suggestion will work too I'm sure. That's the joy of this, the trial/error/success. Good luck.
hondo Posted November 3, 2007 Author Posted November 3, 2007 Ok, I see I need to be very specific, which is ok, I am new on here, I know a lot about british sports car,,, british sports car forum, I am using skylighters tooling, I made my own grapvine charcoal and using 55g potassium nitrate, 21g grapevine charcoal, 14g sulfur and 10g- 80 mesh charcoal. Ball milled for 4 hours, but not the 80 mesh charcoal it added after the fact, pressed in an 8 ton press, I dont know the pressure cause I dont know how to affix a gauge so I kind of use the same amount of strokes. to start I add 10 grams of clay for the nozzel then I add 10 grams of powder at a time press repeat till I get above the spindal 10 more grams of BP and then 10 grams of clay plug for the top. the rockets work well only 1 CATOs, so I am wondering if I should press the clay plug at the top, drill a pass fire hole and then press 5 to 10 grams of delay and add the header? it sure is a trial an error and I live in the city too so not much testing in the back yard but I love the smell of BP
mormanman Posted November 3, 2007 Posted November 3, 2007 Ok, I see I need to be very specific, which is ok, I am new on here, I know a lot about british sports car,,, british sports car forum, I am using skylighters tooling, I made my own grapvine charcoal and using 55g potassium nitrate, 21g grapevine charcoal, 14g sulfur and 10g- 80 mesh charcoal. Ball milled for 4 hours, but not the 80 mesh charcoal it added after the fact, pressed in an 8 ton press, I dont know the pressure cause I dont know how to affix a gauge so I kind of use the same amount of strokes. to start I add 10 grams of clay for the nozzel then I add 10 grams of powder at a time press repeat till I get above the spindal 10 more grams of BP and then 10 grams of clay plug for the top. the rockets work well only 1 CATOs, so I am wondering if I should press the clay plug at the top, drill a pass fire hole and then press 5 to 10 grams of delay and add the header? it sure is a trial an error and I live in the city too so not much testing in the back yard but I love the smell of BP Affixing a gauge (it means attaching right) is pretty easy depending on what kind you have. Give me/us a full name of the gauge or take a couple detailed photos.
Mumbles Posted November 3, 2007 Posted November 3, 2007 Normally the delay is pressed before the top plug. When using a delay, I don't see much use in using a top plug. It is mainly to contain pressure when the fuel gets up there and make a little jet of hot gas to light the fuse. When the delay comp is burning, there is no pressure buildup.
hondo Posted November 3, 2007 Author Posted November 3, 2007 I have a bottle jack 8 ton unit, and there is no port to screw a gauge into, so unless I drill a hole and tap it, I cannot attach a gauge unless some one out in pyro land has drilled, taped and screw in a gauge, I figure you have to find the high pressure side of the jack, I saw on the net where you can buy bottle jacks that have ports for attaching a pressure gauge but I dont want to spend 400 for the jack and 200 for a gauge
WarezWally Posted November 3, 2007 Posted November 3, 2007 I remember seeing a guide somewhere to install a gauge on a bottle jack, ill try locate it.
pudidotdk Posted November 3, 2007 Posted November 3, 2007 I remember seeing a guide somewhere to install a gauge on a bottle jack, ill try locate it. http://www.passfire.com/archives/issue2_10/tool2_2_10_1.asp
hondo Posted November 3, 2007 Author Posted November 3, 2007 I am currently ball milling 45g potassium nitriate, 45g charcoal and 10g sulfur and see how that works for a delay
oskarchem Posted November 3, 2007 Posted November 3, 2007 I remember seeing a guide somewhere to install a gauge on a bottle jack, ill try locate it.http://www.passfire.com/archives/issue2_10/tool2_2_10_1.asp humm.. You see you need to be a passfire member to see that I am thinking of giving the 40$ for it...
cplmac Posted November 4, 2007 Posted November 4, 2007 Best 40 bucks you will ever spend on Pyro. There is so much information on Passfire it's ridiculous. The forums there sport some of the best hobby builders in the country. That fee will get you access for closer to three years than one.
FrankRizzo Posted November 4, 2007 Posted November 4, 2007 Yep, definitely the best $40 you will ever spend.
psyco_1322 Posted November 5, 2007 Posted November 5, 2007 Um or you could just add a few inches of fuse to your header for a delay. Then you could send me about $10 and id send you about a pound of firefox delay comp.
Aquarius Posted November 7, 2007 Posted November 7, 2007 I use a slow mix of BP and add 10% of linseed oil. It smells a bit, so I'll switch to "Baby Oil" instead. I am not sure, but will storing make a impact on the delay? Will it dry out and make the delay burn faster?My 7 mm of delay burns for about 3-3.5 secs and seem reliable, but I suspect drying has an effect on the burn rate. Also, I know some use Sodium bicarbonate. I'll might try that as well.
Mumbles Posted November 7, 2007 Posted November 7, 2007 Linseed oil will "dry" in the effect that it cures to a plastic-like substance. This may have some effect. A relatively non-drying oil such as vaseline or mineral oil. I hope mineral oil is what you're talking about, and not an oil derived from....ehem, another source.
Aquarius Posted November 7, 2007 Posted November 7, 2007 No, "Baby oil" is not made from the little cute things that barf and cry all night. It is a mineral oil used for massaging my wife...
Mumbles Posted January 29, 2008 Posted January 29, 2008 I see no use in placing KNO3/Sucrose above a blackpowder fuel increment. It doesn't really give any sort of tail, and isn't very storage stable. To me the core part of the rocket is to get it airborne, and then the actual artistry takes place. Unless your name is Steve LaDuke, or cplmac, there is very little artistry in the motor itself. Glitters are some of my favorite delays. Strobes in the appropriate rockets are nice as well. Colored star comps can be used. There are two especially pretty delays, coincidentally used by two especially prolific rocket builders. 39J by Tom Rebenklau, and Chrysanthemum of Mystery with a few percent Ti by Steve LaDuke.
whitefox77 Posted January 29, 2008 Posted January 29, 2008 Chrysanthemum of Mystery with a few percent Ti by Steve LaDuke. I used Chrysanthemum of Mystery for the delay in the rocket I made. Of course it's nozzle blew out so it never left the ground, resulting in 10g of KNO3/Al micro-stars going off on the ground (sort of like an unplanned mini-mine). In any case, I'll remember that it makes a nice effect.
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