Estes's Ignitors and the Plug

[shockie]

Well, unlike the litigation about the Johnson & Johnson product that was found to contain carcinogenic asbestos (commonly co-localized in talc deposits), there really is no prospective evidence of any definitive linkage between pure talc and and mesothelioma or ovarian cancer. Or J&J wouldn't still be on the shelves of every Walmart and CVS. And it is simple to find around here. I'd guess elsewhere, too. Unless it all got hoarded along with the buttwipe. Love nylon, but if you're using plastic like a gadzillion LPR/MPR rockets still do, you can either wear a hazmat suit, stand upwind when powdering your chutes, try graphite, or worry about something probably a little more hazardous like crossing a busy street.

Fake news

 

[BABAR]

IPowdered graphite is second only to air float charcoal for making/spreading mess. It's also more flamable.

I DID know about the mess. I didn’t know about the flammability, so thanks.

I do use it on the launch rod (my original Estes rods are bent and discarded, the hardware store ones work fine but I do wipe them with sandpaper once in a while and throw on a pinch of graphite powder. It’s very little, almost all of it is gone by the time rocket is loaded, so I think I am okay. I will take extra care to keep the lid on it and keep it away from my motors now, though!

 

[SharkWhisperer]

I DID know about the mess. I didn’t know about the flammability, so thanks.

I do use it on the launch rod (my original Estes rods are bent and discarded, the hardware store ones work fine but I do wipe them with sandpaper once in a while and throw on a pinch of graphite powder. It’s very little, almost all of it is gone by the time rocket is loaded, so I think I am okay. I will take extra care to keep the lid on it and keep it away from my motors now, though!

Graphite is nearly inert in flammability. I'm sorry but that statement is just not accurate. I have pounded some nozzles containing 25% graphite (usually less) before to act as a lubricant in bentonite/grog consolidation, and there is zero nozzle erosion indicating graphite burning. This is basic fireworker chemical knowledge.

Yeah, while technically a cloud of any finely powdered substance is ignitable under specific conditions, I'd sit in a chair with a lit cigar in my mouth holding two lit blowtorches and let somebody blast me with powdered graphite in any format they chose: 10 tries for a $10k (it'd be quite messy).

Then try intimately mixing superfine graphite with essentially any common oxidizer and see if you can get that burning nicely with a blowtorch--5 gets you 10 that you will be unable to. Then substitute the graphite with talc and try again. No burn. Then sub the crappiest hardwood airfloat charcoal for the graphite and hit it with the torch (or just a piece of low-temp fuse)--just stand back if you enjoy your eyebrows.

There is absolutely no risk of starting fires in model rocketry by including graphite, but a 100% chance of making a huge mess that can be impossible to clean up! Black boogers for weeks...

 

[BABAR]

Graphite is nearly inert in flammability. I'm sorry but that statement is just not accurate. I have pounded some nozzles containing 25% graphite (usually less) before to act as a lubricant in bentonite/grog consolidation, and there is zero nozzle erosion indicating graphite burning. This is basic fireworker chemical knowledge.

Yeah, while technically a cloud of any finely powdered substance is ignitable under specific conditions, I'd sit in a chair with a lit cigar in my mouth holding two lit blowtorches and let somebody blast me with powdered graphite in any format they chose: 10 tries for a $10k (it'd be quite messy).

Then try intimately mixing superfine graphite with essentially any common oxidizer and see if you can get that burning nicely with a blowtorch--5 gets you 10 that you will be unable to. Then substitute the graphite with talc and try again. No burn. Then sub the crappiest hardwood airfloat charcoal for the graphite and hit it with the torch (or just a piece of low-temp fuse)--just stand back if you enjoy your eyebrows.

There is absolutely no risk of starting fires in model rocketry by including graphite, but a 100% chance of making a huge mess that can be impossible to clean up! Black boogers for weeks...

I am relieved by this additional information. Thanks. It does work well to slick down a cheap launch rod, but it is messy!

 

[jrap330]

I originally was not a fan of the new igniters. Then I read this tip from der MicroMeister. If you don’t know who he is, he’s the guy responsible for most of the MicroMaxx forum, although @kuririn seems to have picked up his mantle. Der MicroMeister passed away not long ago. By the way, if you launch a rocket recently and it never comes down, it’s a good bet he grabbed it.

Problem is not the igniters. It’s the plugs. Ditch ‘em.

Use wadding.

Start with about a 1x1 inch square for B or C. (1.5x1.5 inches or thereabouts for an A or D motor)

After rolling into a ball, taper on side a bit so it “fits” a bit into the nozzle

Gently widen the “V” of the igniter. Careful not to break the thin wire, just spread enough to the main wires don’t cross and short circuit in the nozzle

Insert igniter into nozzle. I TRY to remember to hold the rocket with the launch lug or buttons TOWARD ME, so when I am done I can bend the wire AWAY. That makes it easier to access the wires on the pad as they face away from the rod or rail.

Because you widened the “V”, the wires will be wider than the bore, they will flex medially to accommodate the bore, keeping the leads on opposite sides. You will feel a “thunk” when the tip hits the propellant.

Drop in your wadding ball, with the taper down so it fits into the nozzle (not much at this point.)

Tamp down with a semi-sharp object, I find the cheap mechanical pencils with the lead retracted work perfectly for 13 mm through 24 mm motors.

The ball of wadding will push the igniter tip toward the exposed grain (should already be touching it anyway) and keep the igniter wires spread apart so they don’t short circuit.

Feel free to press hard. For small to medium LPR rockets, I can generally GENTLY support the weight of the rocket by the igniter leads after tamping.

Bend the wires AWAY from the launch lug or rail buttons.

If I am not launching immediately, I stick a square of tape over it to hold everything together.

I am pretty close to 100% success with this.

Straight trails!View attachment 446548View attachment 446549View attachment 446550View attachment 446553View attachment 446554View attachment 446555View attachment 446556View attachment 446557View attachment 446558

I finally used the wadding instead of plugs today. 2 launches successful and one lost Custom Elite on an A8 engine...Geez...shock cord broke and found nosecone near pad...body....somewhere out there. Again poor eyesight and sunset.

 

[RocketTree]

Used 130 Estes igniters in last 12 months, and never once had a problem or misfire.

Here is what I do:

Tip the rocket on its side, insert the igniter. Use your thumb on the pointed leads of the igniter to bottom-out it out within the motor. Firmly pressing it deep into the bore and angled toward whichever side of the nozzle you choose, press in the plug. Now you can gently form the igniter leads to the side and upward.

If thats what you were doing, I would suggest trying a controller with li-po battery. Might be an entirely different issue. When you remove an igniter, it will sometimes appear broken.

 

[jrap330]

Used 130 Estes igniters in last 12 months, and never once had a problem or misfire.

Here is what I do:

Tip the rocket on its side, insert the igniter. Use your thumb on the pointed leads of the igniter to bottom-out it out within the motor. Firmly pressing it deep into the bore and angled toward whichever side of the nozzle you choose, press in the plug. Now you can gently form the igniter leads to the side and upward.

If thats what you were doing, I would suggest trying a controller with li-po battery. Might be an entirely different issue. When you remove an igniter, it will sometimes appear broken.

Yeah, I would think holding engine upright on a surface and gently putting in plug was the most careful method of insertion since I am looking directly down into nozzle/engine. Maybe someone was righ, I push the plug directly between ignitor leads and therefore broke the wire. Again did not have this problem 15-20 years ago and these are 15-20 yr old engines/igniters. I will give you method a shot...thanks.

 

[prfesser]

Graphite is nearly inert in flammability. I'm sorry but that statement is just not accurate. I have pounded some nozzles containing 25% graphite (usually less) before to act as a lubricant in bentonite/grog consolidation, and there is zero nozzle erosion indicating graphite burning. This is basic fireworker chemical knowledge.

Yeah, while technically a cloud of any finely powdered substance is ignitable under specific conditions, I'd sit in a chair with a lit cigar in my mouth holding two lit blowtorches and let somebody blast me with powdered graphite in any format they chose: 10 tries for a $10k (it'd be quite messy).

Fun fact: graphite and diamond have the same melting (actually, decomposition) temperature, around 3500 C. Diamond is a trifle expensive as a nozzle material, though. Heat it to that temperature in the presence of oxygen and you form some extremely expensive carbon dioxide...

In a couple of student research projects some years ago I wanted to look at the effect of varying the percentage of several ingredients. But (for example) if the propellant was 70% X and 30% Y, increasing X by 5% means that Y decreases as well. The wrinkle I came up with was to make a control propellant that contained, say, 10% graphite powder as an inert additive, so the propellant was 60% X, 30% Y, and 10% graphite. To increase X by 5%, the graphite was decreased by 5%, so the test mix would be 65% X, 30% Y, and 5% graphite. That way all the other ingredients stayed at the same percentage. Not a perfect solution but it seemed to work okay.

Best -- Terry

 

[SharkWhisperer]

I guess you could call graphite "inert". But apart from being non-inflammable under most human circumstances, it could by heat transfer/blocking properties play more of an active role in flame propagation than just being an "inert" burn-blocker". It's used as an opacifier in commercial BP coatings (and other applications), not just to simply slow a burn down (though it does) but to actually regulate the burn so that the outer granule burns slowly, and completely, while flame transfers to the granule's inside so you get a simultaneous inner/outer burn--there's high-speed video of the effects. It's not perfect, but it does have an effect. It's also a great lubricant for keeping Goex BP granules separated, particularly in humid circumstances. If anybody looks at the chemical structure of graphite "crystals" and how they interact, they'll understand immediately why it makes a great lubricant. Pictures make it simples.

Diamond dust as a burn inhibitor, hmmm....? I usually use sodium bicarbonate added to my propellant to slow burn rate for delay charges in "research" (everyday) BP rocket motors, because it's cheap/easy/stable, but I'd be willing to try diamond dust, too if there's any donors available! Graphite, I sometimes (rarely--only loooong burning motors) do I add to my BP motor nozzle mix. Some do add it religiously and it is neither expensive nor will hurt nozzle function, but never had the need myself (yet). The pound I have will probably outlive me... Graphite you can turn to airfloat powder just by sneaking up on it and saying "Boo!". Diamond, maybe not so soft, but I'll bet it'd make a fantastic BP rocket nozzle grog (think hammer-crumbled ceramic) substitute to add a little "bite" between your nozzle mix into the surrounding cardboard tube to reduce the likelihood of the nozzle blowing out.

And I iterate that anybody that can get graphite to "burn" at STP has both my accolades and admiration!

Fun fact: graphite and diamond have the same melting (actually, decomposition) temperature, around 3500 C. Diamond is a trifle expensive as a nozzle material, though. Heat it to that temperature in the presence of oxygen and you form some extremely expensive carbon dioxide...

In a couple of student research projects some years ago I wanted to look at the effect of varying the percentage of several ingredients. But (for example) if the propellant was 70% X and 30% Y, increasing X by 5% means that Y decreases as well. The wrinkle I came up with was to make a control propellant that contained, say, 10% graphite powder as an inert additive, so the propellant was 60% X, 30% Y, and 10% graphite. To increase X by 5%, the graphite was decreased by 5%, so the test mix would be 65% X, 30% Y, and 5% graphite. That way all the other ingredients stayed at the same percentage. Not a perfect solution but it seemed to work okay.

Best -- Terry

 

[prfesser]

Diamond dust as a burn inhibitor, hmmm....? I usually use sodium bicarbonate added to my propellant to slow burn rate for delay charges in "research" (everyday) BP rocket motors, because it's cheap/easy/stable, but I'd be willing to try diamond dust, too if there's any donors available! Graphite, I sometimes (rarely--only loooong burning motors) do I add to my BP motor nozzle mix. Some do add it religiously and it is neither expensive nor will hurt nozzle function, but never had the need myself (yet). The pound I have will probably outlive me... Graphite you can turn to airfloat powder just by sneaking up on it and saying "Boo!". Diamond, maybe not so soft, but I'll bet it'd make a fantastic BP rocket nozzle grog (think hammer-crumbled ceramic) substitute to add a little "bite" between your nozzle mix into the surrounding cardboard tube to reduce the likelihood of the nozzle blowing out.

And I iterate that anybody that can get graphite to "burn" at STP has both my accolades and admiration!

Carbonates and bicarbonates slow the burn of APCP. I found that 5% baking soda added to a batch of APCP kept it from sustained burning at room temperature. It could be ignited with difficulty but went out moments after the flame was removed.

 

[bobbyg23]

I am pretty close to 100% using the plugs.

Same here.

 

[bjphoenix]

Tip the rocket on its side, insert the igniter. Use your thumb on the pointed leads of the igniter to bottom-out it out within the motor. Firmly pressing it deep into the bore and angled toward whichever side of the nozzle you choose, press in the plug. Now you can gently form the igniter leads to the side and upward.

I've done this the past 3 or 4 years and had 100% luck too. Most of my igniters are the slightly older ones with black coating but a couple of weeks ago I used some new ones with the white. I had one pink plug that just didn't want to go in. I was in a hurry and may have left a lot of the extra on the tip of it, but it launched. I've also at club launches in recent years used the nichrome and wadding trick and it still works. I think the reason Estes came up with the newer designs was to work with small batteries. Long ago we used nichrome with small batteries and it was always a challenge (we were poor kids). With enough battery any igniter will probably work. I still have a small package of nichrome in my range box just in case. Back in the old days the advice was to wrap the nichrome around the tip of a ballpoint pen, then use the same ballpoint pen to push the wadding into the engine.

At our club launches the scouts have a lot of trouble with igniters. Don't know if they are installing them wrong but someone even suspected that they were trying to reuse them.

 

[Cape Byron]

At our club launches the scouts have a lot of trouble with igniters. Don't know if they are installing them wrong but someone even suspected that they were trying to reuse them.

I've often reused the older style Estes Igniters. Ignition is a fraction later, but unless you're clustering or drag racing...

 

[BEC]

I've also at club launches in recent years used the nichrome and wadding trick and it still works. I think the reason Estes came up with the newer designs was to work with small batteries. Long ago we used nichrome with small batteries and it was always a challenge (we were poor kids). With enough battery any igniter will probably work. I still have a small package of nichrome in my range box just in case. Back in the old days the advice was to wrap the nichrome around the tip of a ballpoint pen, then use the same ballpoint pen to push the wadding into the engine.

The Solar Igniter was introduced in 1972 along with the 4-AA-cell Solar Launch Controller. So yeah....for small cells. But that was a LONG time ago. That said, I do remember wrapping the nichrome around the launch key to make a coil, then retaining it with wadding.

At our club launches the scouts have a lot of trouble with igniters. Don't know if they are installing them wrong but someone even suspected that they were trying to reuse them.

I TRY to get them to install them either as @RocketTree said or to put the rocket nose down, drop the straight igniter in, then put in the plug. Only after that allow them to bend the leads over. But some bend the leads first (which can prevent the tip from going where it needs to go) and some leave the little L-shaped bit on the tip of the plug, which leads to erratic results. They are also not at all careful about not twisting/bending the igniter so that it's shorted in the nozzle. All of these lead to misfires.

I have a big Scout group coming to the club launch in late July....so I expect lots of recycled launches.

In general I've personally had pretty good success even with the much-maligned "Solar Starters" but I am looking forward to when the StarTech ones start showing up in the field as they allow you to mess up the installation (though not short it) and still work.

 

[bjphoenix]

The Solar Igniter was introduced in 1972 along with the 4-AA-cell Solar Launch Controller. So yeah....for small cells. But that was a LONG time ago.

I was launching rockets a long time before 1972, maybe 9 years. When did the straight igniter come out? A long piece of heavy nichrome that had blue pyrogen patches on it, you had to cut it into 3 pieces and bend to fit the motors. That had to have been around mid-1960s.

 

[BEC]

Those flattened-nichrome-with-blue-stuff-on-them igniters are the first I remember being packaged with motors, even though I remember doing the nichrome wire coil thing....and i started in the hobby in 1967, I think (and got out for a long time upon going away to college in the fall of 1974). But I can't say when they first appeared.

 

[Alan15578]

I was launching rockets a long time before 1972, maybe 9 years. When did the straight igniter come out? A long piece of heavy nichrome that had blue pyrogen patches on it, you had to cut it into 3 pieces and bend to fit the motors. That had to have been around mid-1960s.

Those were Astron Igniters. They are still my favorite; they are very robust and reliable. The center section of the nicrome wire was actually hammered thinner, si it would easily fold in the right place and have higher resistance there, without needing a bridge wire. Furthermore, you could cut them to have longer leads for clusters, and shorter leads for single motor use. You hold them in place with a small wad of recovery wadding tamped into place. You can actually grab the igniter lead with a pare of pliers and hold up the whole rocket. For clusters, you can then twist the leads together of adjacent motors. Thus, you only need one clip whip, instead of three, to get that old Saturn V going. Never twist the leads of an igniter/starter with a bridge wire; you will often break the weld and ruin the igniter. The Sure-Shot igniter also worked well, but it was more fiddly.

The Solar igniters are more fragile,and even the pyrogen would often crumble off. However, you can simply clip them to the launch rod with a clothes pin and lower the rocket onto the igniter. I actually liked the Solar launcher. I was able to squeeze 5 AA Nicad cells into mine and that worked well, even with Astron igniters. Also, if you have one of those controllers that uses a single 9V battery, try and find a 7 cell rechargeable Nicad replacement battery.

I'm hoping that I will like the new Solartech starters as much as the old Astron.

 

[BEC]

I was launching rockets a long time before 1972, maybe 9 years. When did the straight igniter come out? A long piece of heavy nichrome that had blue pyrogen patches on it, you had to cut it into 3 pieces and bend to fit the motors. That had to have been around mid-1960s.

In looking for something else, I just stumbled upon the answer to this question. They are announced as new in the June 1965 Model Rocket News. Last page here: http://spacemodeling.org/jimz/mrn/mrn_v05n02.pdf

 

[dpower]

<snip>I'm hoping that I will like the new Solartech starters as much as the old Astron.

I've flown quite a few of the StarTech starters. They're an improvement over the Solar Starter, but still not as good as the Solar Igniter. With 4 AA batteries, they take longer, and are less energetic than the Solar Igniters, but do produce some flame, unlike the Solar Starters. They work very well with the Estes PSII controller (9V), and the old Estes Pro Series Command Control (7.2V).