usapyro Posted January 2, 2012 Posted January 2, 2012 (edited) My parents happen to use a hydraulic custom built extrusion machine for one of their businesses. It can make six 12 inch long 5mm rods with a pull of a handle in seconds. I was working a bit with some cordite type compositions last summer that could be hand rolled into rods and they were flexible when dry. They worked good as fuse. It just gave me an idea though... Isn't parlon (chlorinated rubber) pretty flexible? I think it would be very easy to find the right binders to make a suitable flexible fuse composition that could be extruded hydraulically into 3mm rods. In fact... I am going to go do some tests on a oxidizer/parlon/charcoal comp to see if this is feasible without the use of exotic nitrates... Does anyone happen to know the Oxygen Balance of chlorinated rubber? Edited January 2, 2012 by usapyro
NightHawkInLight Posted January 2, 2012 Posted January 2, 2012 Cool idea! I haven't thought about making a flexible fuse that doesn't have some sort of outer coating. I'm interested to see how it works for you. If it goes well I'm sure it would be easy enough to make a PVC extruder that can be used on a typical H frame press.
usapyro Posted January 2, 2012 Author Posted January 2, 2012 (edited) I happen to have hundreds of feet of fuse, but this is such an interesting idea that I will do some tests in the next few days. Btw, the receiver on my parents setup is some sort of teflon/nonstick surface that stuff slides on. Another solution would be to have the stuff pushed out onto some paper that automatically is rolled out with the speed of the extrusion. Edited January 2, 2012 by usapyro
NightHawkInLight Posted January 2, 2012 Posted January 2, 2012 I also have plenty visco and time fuse, I'm more interested in specialty fuses like falling leaves and maybe some jumbo extruded flying fish. Maybe even some with a microstar matrix if the process works well enough. You could coat the fuse easily enough after it cures by painting or dipping it in a solution of the original binder.
dan999ification Posted January 2, 2012 Posted January 2, 2012 (edited) i take it that it will not stay flexible once dried, how can you stop it breaking and work with it, or is it for short lengths only and a specific purpose? like micro star matrix's, giant fish fuse would be great and sell like hot cakesperhaps you could extrude a string in the comp to reinforce it in the event of a breakage. dan. Edited January 2, 2012 by dan999ification
usapyro Posted January 2, 2012 Author Posted January 2, 2012 (edited) Nope, it stays decently flexible... In my experience working with a comp consisting of half sulfurless BP + half NC/NG 15/85... (Something around there, forgot the exact comp... It was last summer.) Acetone solvent. The stuff stayed flexible when dried. A four inch long 4mm rod of the stuff could be bent around an inch and it would snap right back. It could be wrapped around something with a 1.5" diameter just fine without breaking, but would not snap back fully. I attribute a lot of the comps flexibility to the fact that it had a lowered density with lots of airspace after the solvent dried out. I used a LOT of acetone... Parlon is chlorinated rubber... And it's nearly as flexible as natural rubber as far as I have read. A 25-30% parlon comp should be flexible. We shall see! I am only looking for enough flexibility that the comp won't crack/snap or break for normal fuse use... Rockets, fountains, pre-quickmatch fuse for mortars, etc... Your not going to be able to tie it in knots or anything like that. If it isn't flexible enough or doesn't burn well enough... Then I guess a certain amount of self oxidized gel is required in the comp to give it enough flexibility. Which would limit it to personal use only. I will test a simple Oxidizer/Parlon/Charcoal, and a Oxizider/Parlon + Bullseye DBSP (40% NG / 55% NC / 5% ETC) comp tomorrow. I am probably going to modify a caulk gun cartridge and use that for testing... Acetone will probably bloody dissolve the thing! Ha Dan, if we have to go down the route of embedding string in the comp, or wrapping it in string... Then we might as well just make a visco machine. Edited January 2, 2012 by usapyro
dagabu Posted January 2, 2012 Posted January 2, 2012 Not really fuse unless it is shielded from side fire, pretty much flexible black match from what I understand about the idea of extruding it into rods. -dag
NightHawkInLight Posted January 2, 2012 Posted January 2, 2012 Not really fuse unless it is shielded from side fire A dip in a solution of the binder used should accomplish that.
Mumbles Posted January 2, 2012 Posted January 2, 2012 Yep, parlon is quite fire resistant actually. A coating with it should be enough to to keep side spit from jumping down the fuse. I suspect this fuse will be somewhat difficult to ignite anyway, so it may not even be a problem. If you want to keep this outside the realm of the HE section there are plenty of other thing plasticizers that could be used. Alkyl phthalates are fairly common, and I bet something like poly(ethylene glycol) would also work quite well. Something like silicone oil or mineral oil may also work. There is plenty of literature on improving flexibility of films and coatings out there if you take the time to look. Reworking the silicone fuse would be interesting too. Getting rid of the potassium permanganate and sulfur that Microtek was a fan of would be a good start.
Recommended Posts