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dhbarr

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In case someone has some handy to measure it might be good to specify pink, green, or white.
 

RocketNut9

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I have been out if the loop for a number of years now. Has there been a change? Back in the day Thermalite was used for any thing pyro firing, lite by a e-match. Also there was only one flavor, red I think was the color.
 

timbucktoo

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I have been using Pyrodex pellet wrapped around an e-match for L & M Loki & AT motors.
 

cavecentral

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Things changed. Now igniters are purchased, kits to make them are purchased, or people make their own.
 

RocketNut9

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All those ingniters require 12 volts to fire. I am working on a flight controller that has a capacitor discharging circuit that only supply 5V @ 1.5 Amps. I found these e-matches on Ebay (https://www.ebay.com/itm/E-match-10...535564?hash=item1eac3a868c:g:6S0AAOSwzgRW0qS4). They work very well with my firing circuit. I was thinking of using them to light Theramalite to do staging and recovery deployment.

So any ideas on how to ignite the pyro charges upper stages?
 

ECayemberg

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I have been out if the loop for a number of years now. Has there been a change? Back in the day Thermalite was used for any thing pyro firing, lite by a e-match. Also there was only one flavor, red I think was the color.
Actually, there were three flavors: slow, medium, and fast. Slow had red wrap on it, Medium had green wrap, and Fast had white wrap. From testing, unsheathed "Slow" has a burn rate of ~0.6"/sec, sheathed is twice that at 1.2"/sec. Fast was in the range of 1"/sec unsheathed.

No current source other than old stashes from "back in the day". Rolls of it can be bought/sold, but the price is usually quite high nowadays.

I do enjoy using it for airstarting BP motors unaugmented (Loc Heavy Duty Beauty is a favorite!). Also use it for airstarting AP motors using Pyrodex pellets in the AP motors.

It is good stuff for simple clustering/airstarting once you get the hang of it! :)

-Eric-
 

georgegassaway

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Yeah, Clsuters and Air-starts were great. Used T-lite with Flashbulbs for clusters for many years. Recent years, have used Quest Q2G2 ignitors for BP clusters, but those have become hard to get..

One of my favorite air-starts was with an R/C Rocket Glider to fly in "G Rocket Glide" At NARAM-34. It took off on an F10 but was a bit heavy for an F10 and also it needed more Total Impulse to qualify as a G powered model. So I had a D12 in a second pod. But I did not want to risk a cluster, in case only one motor lit. So, Thermalite in the D12, ignited by the exhaust of the F10. Took off a bit slow than about 1-2 seconds later the D12 lit and it was like going to "Afterburner" while the D12 burned. Then the D12 burned out and the F10 continued for the rest of its 8 second burn, at a much faster velocity than before. Flight two, took it a step further, with a second F10. It lit about 4 seconds into the first F10 burn, but the model got so FAST with the combined thrust until the first F10 burned out, that the model almost went out of control, pitching nose down slowly and full up elevator could not stop it. Worked out though, first F10 burned out before it got too far off-vertical and I got it under control for the rest of the 2nd F10 burn.

And that was the fun, simplicity, but also risk of Thermalite for an air-start like that. I could not time the ignition of the second F10 as precisely as I needed it to (wanted it to ignite 6-7 seconds after the first F10 lit, for only a 1 to 2 second thrust overlap). But that was the only time I really needed an air-start by Thermalite to be that accurately timed.

Nearly all of us (without old stock, or in Canada) have learned to fly without Thermalite. But, still, there's still times when it would be SO NICE to use , instead.

 
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RocketNut9

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So if I under standing what you all have been saying Thermalite is no longer available in the USA? If so what is it replacement if any?
 

cvanc

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It hasn't been available for years. There really isn't a direct substitute - you'll have to come up with a different idea, especially if you intended it to create a (more or less) specific amount of delay on an airstart or whatever. Sorry.
 

RocketNut9

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Thanks for the info. Looks like I have to redesign my pyro units.
 

ksaves2

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There are recipes floating online if one cares to search. Firefox has a DIY book with thermalite formulas but one has the hassle of locating an acquiring the chems to make it.
It's not impossible though remember to mix the liquids first and add the powders (oxidizers) sequentially so they are fully wetted. Some instructions list mixing the
powders dry which the pyro folks may feel comfortable with but a simple spark could set the powders off and cook whomever is standing there. Kurt
 

dave carver

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All the same. Gonna say 1/16"

I think that's about right for a diameter. It would slip inside either a Teflon tube or shrink wrap with two results. Inside a Teflon tube it burned at the normal rate making for a fairly reliable delay. No such thing happened with shrink wrap. It went from inches per second to yards per second. The shrink wrap constricts and a wavefront of flame shoots up the inside of the tube. I made small test pieces , it would shoot across a sheet of plywood like they were rocket propelled. I like it for igniting outboard in a 3-in-line Titan lll like. One piece bridging over the central motor, igniting it the sideboards lit almost immediately after the main motor. The magical rolls are rumored to hide in the bottom of old timers launch boxes....
 

cavecentral

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Yeah 1/16th is about right, then wrapped in wires and then some ribbon.
 

Johnly

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Just measured some that I have. .062" off the reel, .048" without the wrap and wires.

John
 

kclo4

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The replacement now days would be a small light weight timer/flight computer wouldn't it? A Raven would be able to do such a thing with extra safety lockets based on altitude/velocity/etc no?
 

RocketNut9

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The replacement now days would be a small light weight timer/flight computer wouldn't it? A Raven would be able to do such a thing with extra safety lockets based on altitude/velocity/etc no?
That's what I am working on, flight computer. The problem I am having now is finding a igniter that fires with 5V@~1Amp. All the igniters I have seen so far require 12V. The firework e-matches, I found on Ebay ([url]https://www.ebay.com/itm/E-match-100pcs-lot-11-81in-For-Fireworks-Firing-System-Electric-Igniters-display-/131738535564?hash=item1eac3a868c:g:6S0AAOSwzgRW0qS4)[/URL], do not burn long enough to light a upstage engine.

If any one knows of such igniter, please let me know.:)
 

dhbarr

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I think many folks supplement w/ a sliver of blue propellant, but there can be diameter issues.
 

rharshberger

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That's what I am working on, flight computer. The problem I am having now is finding a igniter that fires with 5V@~1Amp. All the igniters I have seen so far require 12V. The firework e-matches, I found on Ebay ([url]https://www.ebay.com/itm/E-match-100pcs-lot-11-81in-For-Fireworks-Firing-System-Electric-Igniters-display-/131738535564?hash=item1eac3a868c:g:6S0AAOSwzgRW0qS4)[/URL], do not burn long enough to light a upstage engine.

If any one knows of such igniter, please let me know.:)
They will if you use a pyrodex pellet with the Ematch...or use a CTI motor with the ignition pellet.
 

cavecentral

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Yeah as others said, augmenting an ematch with pyrogen, propellant slivers, or pyrodex pellets works well for low current ignition (staging, timers, etc.).
 

cavecentral

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Pretty big - 50 cal are most common - not going through a small nozzle.
 

RocketNut9

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It is a three stage bird. The first stage will be 9977M2245-P and stage 2 & stage 3 will be 2645L265-P. That is if I can find a low voltage iginter. I am going to test the firework e-match and a Pyrodex pellet.
 

rharshberger

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It is a three stage bird. The first stage will be 9977M2245-P and stage 2 & stage 3 will be 2645L265-P. That is if I can find a low voltage iginter. I am going to test the firework e-match and a Pyrodex pellet.
Send a PM to CJ aka Blackjack2564 aka Jim Henderson (cant remember the exact numbers after blackjack) asI believe he uses the pyrodex pellets with ematches method.
 
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