Making Thermalite
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MarkABrown
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I remember seeing that site once before. Unfortunately, I don't have a link to it anymore.
hokkyokusei
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Could someone explain to me what thermalite is, and what it's used for? I don't think I've ever seen it here in the UK.
Silverleaf
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Thermalite - A material, originally used to detonate plastic explosive, which burns at a controlled rate and high temperature. Used with rocket motors as an ignition enhancement. It can be ignited by electric (nichrome) means, flash bulbs or the exhaust of a previously started motor. It comes in three burning speeds color coded as pink (slow), green (medium) and white (fast). For a rough order of magnitude, slow is around 1/2 in/sec and fast is 2 1/2 in/sec in free air, but this can be affected by temperature, humidity, pressure and whether or not the fuse is sheathed in a tube.
In addition, its a low-explosive device in the shape of narrow string, similar to detonation cord. Thermalite is often used to enhance the efficiency of igniters in large-diameter composite motors, and is sometimes used for airstarting motors. The possession and use of Thermalite now requires a LEUP to be issued from the BATF.
Hope that helps,
In addition, its a low-explosive device in the shape of narrow string, similar to detonation cord. Thermalite is often used to enhance the efficiency of igniters in large-diameter composite motors, and is sometimes used for airstarting motors. The possession and use of Thermalite now requires a LEUP to be issued from the BATF.
Hope that helps,
Elbmod
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Is this what you're looking for???
https://www.wecreate4u.net/dwilliams/thermalite/thermalite.html
Pete
https://www.wecreate4u.net/dwilliams/thermalite/thermalite.html
Pete
hokkyokusei
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Is it like visco?
marvSRG
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Elbmod,
Yep, that's it! Thanks a bunch. I wanted to check it out again....
hokkyokusei,
The only similarity to visco is the fact that it's fuse. Thermalite burns much hotter, and can be time controlled, also when sheathed with heat-shrink tubing it burns almost instantly. It works great for ignition, staging, and airstarts. But unfortunately, as with almost everything these days, it's regulated by the BATF
Yep, that's it! Thanks a bunch. I wanted to check it out again....
hokkyokusei,
The only similarity to visco is the fact that it's fuse. Thermalite burns much hotter, and can be time controlled, also when sheathed with heat-shrink tubing it burns almost instantly. It works great for ignition, staging, and airstarts. But unfortunately, as with almost everything these days, it's regulated by the BATF
hokkyokusei
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Originally posted by marvSRG
The only similarity to visco is the fact that it's fuse. Thermalite burns much hotter, and can be time controlled, also when sheathed with heat-shrink tubing it burns almost instantly. It works great for ignition, staging, and airstarts. But unfortunately, as with almost everything these days, it's regulated by the BATF
From what I see in the link, I don't think I've ever seen thermalite in the UK. I've seen some other stuff used for fairly similar purposes - such as ensuring ignition, but that's quite different. It is approx 2mm in diameter, brown, covered in a yellow/green plastic with what appears to be a very thin wire down the centre.
Not sure what it's real name is, everyone seems to refer to it as "slow". As in the opposite of "quickmatch".
Lee Reep
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If you are looking to make igniters, try FireFox in Idaho. Their Liquid Element is great. You dip fine gauge wire (I use pairs from CAT5 cable) into it, and it ignites black powder motors just fine. Liquid Element is conductive, so you do not need a nichrome bridge wire for lighting it. It glows a little, with a few sparks, much like Estes ingniters.
For composites, you can redip in another pyrogen, like their PyroMax. These produce a white hot ball of fire that will ignite anything.
This URL works . . . Yes, I know it is 14 years later !
https://www.brianredmond.net/dwilliams/thermalite/thermalite.html
https://www.brianredmond.net/dwilliams/thermalite/thermalite.html
jimzcatz
Boss, Carolina Rocket Mafia
ABSOLUTELY NOT !
Visco is cannon fuse. It will not light with a flashbulb or ematch,typically anyway. YMMV.
Don't diaper the solids. Get the liquids mixed, do (wet out) the metals mixing into the liquids and oxidizer last.
Problem is acquiring all the fix'ins but a little goes a long way. Nice
"starter". Mix or as a base for MTV starter.
Blackleaf99
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I realize this is an old thread, but here is something.
The Encyclopedic Dictionary of Pyrotechnics, Issue 34 lists the following
Thermalite™ – A type of igniter cord formerly manufactured by Canadian Safety Fuse.
The Encyclopedic Dictionary of Pyrotechnics, Issue 34 lists the following
Thermalite™ – A type of igniter cord formerly manufactured by Canadian Safety Fuse.
I'm not Kurt, but I think he was trying to say "don't dry mix the solids" and his autocorrect changed it to diaper. Unless he's got a very unusual mixing process
rharshberger
Well-Known Member
Diapering is a mixing process, the materials are placed in the middle of the sheet and then corners are alternately picked up to roll the products together very gently.I'm not Kurt, but I think he was trying to say "don't dry mix the solids" and his autocorrect changed it to diaper. Unless he's got a very unusual mixing process
https://pyrodata.com/definitions/Diaper-method
I spit out the term verbatim. I think the Pyro people use it but yes dry mixing the fuel and oxidizers like Pyro people do is an
unnecessary risk when making a pyrogen dip. The pyro folks who deal with dry powders will stick it in a casing, stuff in a mandrel and either use a press or a freaking hammer to compress the dry mix. I don't have cojones to do that and those that do have my respect for knowing what they can get away with.
My mother never let my brother and I have the "ashcan kits" by mail (spell that M-80's) but did allow us to make Roman Candles and smoke bombs from kits. I remember "diapering" the "fixings" and mashing them in the Industrial casings for 6 minute smoke bombs using a dowel rod and tamping the blowing and delay powder for the stars for the Roman Candles. She probably saved me and my bro from injuring ourselves.
unnecessary risk when making a pyrogen dip. The pyro folks who deal with dry powders will stick it in a casing, stuff in a mandrel and either use a press or a freaking hammer to compress the dry mix. I don't have cojones to do that and those that do have my respect for knowing what they can get away with.
My mother never let my brother and I have the "ashcan kits" by mail (spell that M-80's) but did allow us to make Roman Candles and smoke bombs from kits. I remember "diapering" the "fixings" and mashing them in the Industrial casings for 6 minute smoke bombs using a dowel rod and tamping the blowing and delay powder for the stars for the Roman Candles. She probably saved me and my bro from injuring ourselves.
Each pyro mixture has its own ignition hazards. For example, BP is highly spark/flame sensitive but is largely insensitive to impact and pressure, which is why centuries of BP rocket makers lived to tell the tale. It's also why BP can be ball-milled. Diapering is the way that smart pyros make "ashcan" flash and/or whistle mix; both are sensitive to flame and impact. Whistle rockets are always pressed, never rammed. Armstrong's mixture is sensitive to being looked at cross-eyed. ;-)
Best -- Terry
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Re firefox-fx.com - got my order a few months ago... it was not smooth or quick despite being on file and ordering in past. took greater than a month to ship. My answer to are they still in business is ‘barely’. Hopefully your order went better than mine as they are a great source of metals and Nitocelliose.
Would it violate any rules if I used nitrocellulose as a replacement for shear pins, for recovery use? it's moldable to shape, and pretty much pisappears on ignition.
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As with any novel deployment method, I think you'd need some compelling evidence for the RSO. A sheet of calculations and a successful test video or two go a long way toward reassurance you're not endangering the agreement with the Land Owner.
Thermalite is useful for some projects in rocketry but is not needed for most of us.
Ummmmm. I wouldn't use it for a cardboard tubed rocket. Would burn a wider hole. In fiberglass, it would probably alter the hole that you drilled by the flame. Stick to 2-56 nylon screws or 4-40 ones.
In cardboard rockets, I'd epoxy a small piece of sharpened aluminum about .020" thick above the shearpin hole. Otherwise, the tube would get ripped through by the nylon shearpin. I shifted to fiberglass tubes and never looked back. (Don't ask me how I learned this!)
Nitrocellulose as a shearpin? Experiment if you want but I think it's a stupid modality. Running wires to all the nitrocellulose shearpins to ignite them sounds like it would be a PITA and totally unneeded.
Plus the stuff may burn too hot and would melt plastic nosecone holes. If you want a single use rocket, have at it. You've been warned.
Kurt
Yeah, seems like a crazy idea this morning. I'm having separation issues with my Falcon heavy model; the boosters' tubes are being separated by the air hitting them, after their nosecone leaves. There is an ejection charge that removes the nosecones well, but it doesn't build enough pressure to kick themselves away from the main, in unison. lol.
I have nylon screws. think I need more area in the seperation passage and less open nose; so I'll try nylon screws, to let it build a bit more pressure.
On the good side, the circuitry I built to detect the ap engine lighting is working well; engine plasma is conductive! APCP much more so than BP engines. I modified my launch controller so that hitting the fire button, and holding it, will detect the main engine lighting, and it hitting a switch(reed switch and magnet) as it moves away from the pad, it fires the boosters. If only one separates, it's pretty unstable. It has to work better before I dare to launch it around people.
I made it such that it could be launched as separate rockets, and it's too much fin combined.
I have nylon screws. think I need more area in the seperation passage and less open nose; so I'll try nylon screws, to let it build a bit more pressure.
On the good side, the circuitry I built to detect the ap engine lighting is working well; engine plasma is conductive! APCP much more so than BP engines. I modified my launch controller so that hitting the fire button, and holding it, will detect the main engine lighting, and it hitting a switch(reed switch and magnet) as it moves away from the pad, it fires the boosters. If only one separates, it's pretty unstable. It has to work better before I dare to launch it around people.
I made it such that it could be launched as separate rockets, and it's too much fin combined.
shockie
High Plains Rocketeer
Prfessr, I'd never heard of that mix, and I totally agree with you; there's a long list of things I won't mess with, and red phosphorus is one of them.
Could you share details of this circuitry? Seems like ignition detection could be useful for all sorts of things.
