MadMax Posted April 27, 2011 Share Posted April 27, 2011 Here's a trick I've used to prime stuff for rapid ignition take your fuse and dip it in some BP dextrin slurry. Around that wrap some nitrocellulose cotton (a.k.a guncotton) The outer layer should be fuzzy and very easy to ignite. To illustrate earlier I went for a quick drive and had a couple gram bp salute which had a fuse of this type. To ignite I took a lit cigarette and quickly swiped it across the primed fuse. That was enough to reliably ignite it. I believe that stars with hard-to-ignite comps or stars in really fast bursting shells like flash burst could potentially benefit from this. So the stars would be "fuzzy" to promote fast ignition. Link to comment Share on other sites More sharing options...
dagabu Posted April 27, 2011 Share Posted April 27, 2011 That would be impractical, expensive, tedious and not effective since gun-cotton creates very little actual heat. NHIL has video of his holding several balls of gun-cotton in his hand, igniting it and suffering no burns. The best hot prime found *so far is fence post prime or one of its variants. Silicon metal is used to hold the heat on the star for and extended amount of time, that placed of a stepped primed star will light almost ant star. -dag Link to comment Share on other sites More sharing options...
Mumbles Posted April 27, 2011 Share Posted April 27, 2011 The concept is a well known one. Make a fluffy or rough surface, and increase ignition. As Dagabu said, NC is probably impractical for regular usage. The fencepost prime he referenced uses diatomaceous earth typically used in pool filters as an agent to rough up the surface. There is though that the porus nature of the material also plays a role, but that is yet to be definitively determined. Some other primes, such as the Veline style super prime, use wood meal. This also makes the surface rather fluffy. Using somewhat coarse metals such as -60 or -100 mesh MgAl may also play a similar role in addition to heating up the prime. Even something as simple as using a granular prime as a final coat is quite effective. I keep all the loose BP and prime that falls off my stars on the drying racks and in the coating bucket for use as a final coating in the future. The surface feels like sandpaper when it's dry. Link to comment Share on other sites More sharing options...
MadMax Posted April 27, 2011 Author Share Posted April 27, 2011 Thanks for the info guys. I probably should have mentioned the gun cotton had been rolled in a bit of dark al powder before being used. This made it burn quite a bit hotter. Really what makes it work is if some of the cotton is submerged into the BP that coats the fuse. Also, I have found when the cotton is integrated into a hot BP this way it doesn't really need to get too hot to ignite the BP. I the NC cotton is pricey but the way I'm using it a little goes a long way. I guess it would be more for use for priming fuses rather then stars - or only in certain niche situations. Example: Aerial salute with stars - assume they don't shatter of course . I'll try to get a pic of it tonight. Link to comment Share on other sites More sharing options...
pyrochris732 Posted April 27, 2011 Share Posted April 27, 2011 ive never had any problem getting stars to light with the old green mix and silicon metal prime. Simple and works like a charm. Link to comment Share on other sites More sharing options...
MadMax Posted April 28, 2011 Author Share Posted April 28, 2011 Don't get me wrong there's nothing wrong with bp/si or veline or any of those. I'm not trying to replace anything - just provide a possible solution. My hope is that it might find a use in situations where conditions are rather extreme and ease of ignition has to be extreme. Maybe open a few new possibilities. BP is easily ignitable and produces high temperatures. NC cotton is extremely easily ignitable but doesn't produce very high temperatures. All I'm trying to do is get the best of both worlds. I tried to upload a pic but it asked for a url so I assume I can't upload pics directly to posts. ive never had any problem getting stars to light with the old green mix and silicon metal prime. Simple and works like a charm. Link to comment Share on other sites More sharing options...
Peret Posted April 28, 2011 Share Posted April 28, 2011 I tried to upload a pic but it asked for a url so I assume I can't upload pics directly to posts.You clicked on the Picture icon at the top. Instead, use the Attach dialog at the bottom. Link to comment Share on other sites More sharing options...
MadMax Posted April 29, 2011 Author Share Posted April 29, 2011 I snapped a pic of a fuse. It's essentially a bp primed fuse that's slightly hairy. The amount of NC here is probably less then a tenth of an mg. You clicked on the Picture icon at the top. Instead, use the Attach dialog at the bottom. Link to comment Share on other sites More sharing options...
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